Tuesday, September 16, 2008

Paddy Fixed - Queanbeyan Diesel Service

G'day All,

Frustrated as hell with testing and retesting most things that I was comfortable with testing and at the end of the day narrowed down to my worst fears - The Diesel Inspector Pump.

Leaving it with Diesel Specialist, they performed a total overhaul (about 75%) of the pump. Bushes, Seals, Rods and a few other bits and bobs. While he was at it I asked him to look at the injectors to see if they needed servicing. Well I got shock of my life, when he comes back to me and said who had last done my injectors ? I told him not me must have been the previous owner and proceeded to ask why ? He told me the injectors where the wrong ones and were severely coked.

So after all that work done, Paddy starts (as expected) perfectly every morning and time since and she runs like a dream, best way to discribe it is the engine runs / revs easier / freer. Yes I had to dig deep into the back pocket :) but it had to be done.

Well for anyone who has been following, my original hopes that since I had the pump seals done 2.5 yr ago I was hoping it wasn't the pump, but the pump was in a bad way.

I hope if you're currently experiencing the same issue(s) as I was and you have ran the tests I did and still no joy, well you better find yourself a good diesel mechanic / specialist. I ended up going to a different diesel specialist to who had done my seals 2.5 years back and went to the follow guys and would high recommend them.

Queanbeyan Diesel Service

www.queanbeyandiesel.com.au

4 Dominion Pl
Queanbeyan East, NSW 2620
(02) 6297 5248




All the best and take care, this blog is hopefully one for the books and put to bed :)


Regards
Mark (One very Happy Pajero Driver)

Thursday, August 14, 2008

Progress Report on Fixing Paddy - Update Test 15 AGAIN!!

Guys,

Paddy stalled really badly this morning, so I bit the "pride" bullet and called The Diesel Specialist again to have a chat. We both had a laugh, I did indeed have it the correct way round the first time (Still don't fully understand the reasons, but correct never the less). I took Paddy round to his place this morning to have a look at the Fuel Primer Pump as I told to him that it appears to be now leaking fuel more noticeably and wanted him to have a look and confirm the replace part.

The Primer Pump was indeed leaking, he confirmed that it was the 60mm bolt on housing version and not the 100mm, and has ordered one which should arrive tomorrow for $80-$100. If this ends up being the problem, then I'm going to be a little pissed at the previous Diesel Specialist who I had taken the primer pump to at the very start of my tests to check to see if it was leaking. They said they had tested it and it was fine and they did not charge me for the test Hmmmmmmmm...... Maybe with all the priming I've had to do I've just put it though it paces and wore it out ?????? or am I being a bit paranoid, and have the right to think they did not actually test it see Test 8 ????

At the end of the day I don't care, If this works I'll just be one happy camper and glad that its fixed.

Regards
Mark

Wednesday, August 13, 2008

Progress Report on Fixing Paddy - Update Test 15

Hmmmm Well I think I stuffed up!

Actually I'm hoping I stuffed up and misheard the diesel specialist's instructions. Basically Paddy started fine this morning as per usually after its been primed / bled. But this afternoon after work it stalled.

In my defense I thought it was strange the way I was installing it, between the Injector Pump and Fuel Filter. After all the specialist was indicating that fuel primer / hand pump was faulty (The little metal flappy thing that is part of the primer) and allowing the fuel to run back to the fuel tank so I did have a little alarm bell ringing, in that the value should be between the fuel primer / pump and the tank.

So I think when I heard him say "pump", I've assumed the fuel injector pump but what he probably had said between the Fuel "Hand" pump and the Fuel Tank, it was a noisy environment I was in when trying to talk to this guy.

This afternoon I put the 1 way value between the Fuel Primer / Filter and the Fuel Tank, so lets see if this configuration works :)

Regards
Mark

Tuesday, August 12, 2008

Progress Report on Fixing Paddy - Tests 14 & 15

Guys,

Well before moving onto tests 14 and 15, I doubly checked all fuel hoses and clamps, and all where good. Paddy was also due an service so I put on new Oil and Fuel Filters this time went with the more expensive option "Ryco" instead of the slightly cheaper brand REPCO. First morning after service it worked fine, but the next day and each morning after the engine would eventually run rough / lumpy and stall if I did not prime. On the bright side it did not take much priming if I primed early (ie before stall). But at the end of the day, no joy.

So I moved onto Test 14:

Test 14 - Inspecting the Fuel Pickup Line and Gauze Filter

Via the inspection hole in the back of the Pajero I was able to access the fuel inspection cover. After removing 8 x 8mm nuts and pulling the 8mm and 6mm fuel lines off the top, the fuel pickup was easier removed for inspection (Being careful not to damage or break the rubber gasket).

From the following 3 photos you can easily see my tank is clean and the fuel gauze filter was clean and the fuel pickup lines not rusted or have any obvious holes in them to allow air in. I put it back in and bolted down and hooked up the fuel lines and bleed the system. Next Morning the as expected since nothing was really done, the engine ran lumpy and eventually stalled.

Image 1 - Gauze Filter / Mesh looks clean





Image 2 - Gauze Filter / Mesh looks clean




Image 3 - Fuel Pickup and return lines look free of rust and holes.





Test 15 - Trying a 1 way Value between Fuel Filter and Fuel Injector Pump

After have a chat to a Diesel Specialist, he recommended trying a 1 way value between the Injector Pump and the Fuel Filter. He seemed fairly confident that it would address my issue and if I remember correctly on both UK Pajero Forum, a few thread had mentioned using a 1 way value.


Image 4 - 1 way Fuel Value




So for $25 I picked up the following 1 way value and installed it and bleed the air out of the fuel lines. Fingers cross, lets see how it goes tomorrow morning.

Cheers
Mark

Monday, August 4, 2008

Farking Hell - The Cold Start is Back!!

Guys,

1 day after posting my "Its Looking Good!" post the car had a hiccup rough idle gave it a rev and all was good, and so I shrugged it off. The next day and almost every odd day since the Engine is back to stalling unless I prime it. So time to continue with the tests:

  1. Firstly I'm going to go back over all the hoses and doubly / triply make sure that they are tight after settling.

  2. Fuel Pickup pipes and Gauze mess Give that a clean.

  3. Blow out the fuel lines make sure nothing is obstructing the flow of fuel

  4. Maybe look at replacing the fuel filter in case I'm unlucky and an obstruction has formed in there.

  5. Reassess my thoughts on having to do the Fuel Pump Seals.



On the bright side, it will keep me entertained a little while longer :) As usual I'll keep you all posted on my tests and results doing one thing at a time till I sort it.

But as I sit here and think, (pray more like it) and shaking my head, I'm still positive its not the seals. I just had 3 weeks of no issues during plenty of -5 degree C cold frosty mornings. Hopefully one of the new pipes clamps just needs a little tightening or the fuel filter has got clogged (please god not with oil ??????)

Regards
Mark

Sunday, July 27, 2008

Progress Report on Fixing Paddy - Its Looking Good!

Guys,

Its nearly been 3 weeks since I've had my Cold Start Issue since replacing the Spill-Over Pipe/Hose. Let me tell you, that It feels GREAT!!! being able to jump into the Pajero and knowing / having the confidence grow again that it will start and not STALL without holding my breath.

At this stage I'm feeling confident that the spill over pipe was definitely a major source of air leak into the fuel system, as it was the last item to be tested / replaced which appears to have cured my cold start problem. But I would like to remind everyone that I have now replaced all fuel hoses, so there is every chance that I had multiple air leaks (They were probably the original hoses so that would make them near 13 yr old) so if simply replacing the spill over pipe for you doesn't solve your issue then don't despair until you have replace all fuel hoses and performed all the tests I'd performed.

Another point I'd like to make/stress is that that this Spill-Over pipe/hose does need to be securely clamped down. For this particular pipe/hose being 4mm the auto / motor and hardware stores near me did not have EFI / hose clamps to securely tighten a 4mm I/D hose which had a O/D of about 6-7mm, most if not all stores indicated that I wouldn't need a clamp for a hose this size.

But you have to trust me on this as clamp that FUCKER down. I was finally able to get a couple of proper hose clamps from a Hose and Clamp store here in Fyshwick, Canberra:

AUSHOSE
83- 85 Gladstone St
Fyshwick ACT 2609

ph: (02) 6280 4777


I still have a couple more tests to try, and am intending on doing still doing them, since I've done everything else it would be a shame to leave these items/things unchecked. As I get round to doing them I'll add a bit of a blog about them just in case it will help you out.

I'm going to give it another few weeks before I call it, and sigh a sign of releif that it wasn't my fuel pump seals.

Thats all for now folks

Mark

Friday, July 11, 2008

Progress Report on Fixing Paddy - I think its fixed !

Well guys,

I think I've got some very good news. For the past three mornings Paddy the Pajero has not had the cold start issue Yahoooooooo!. Now I don't want to jinks myself yet and will wait a another week or so before I'll rest at ease. But yes !!!!! Paddy had started and ran with no stalls since replacing the Fuel Spill Over Pipe / Hose and hose clamps.

Well thats all I'm going to say for now, I'll give it a few more days / weeks before I believe it myself , but I think I've got it. It has not started more than two days in a row with no issue for several months, so fingers crossed :)

Cheers
Mark

Tuesday, July 8, 2008

Progress Report on Fixing Paddy - Test 13

Well still no joy, however definitely feels like I have more power after cleaning out the fuel vapor check valve. So after giving it a couple of days I decided to go on to Test 13.

13. This test dealt with the fuel spillover pipe / hose which is connected to the Injector Spill Rail (at the 2nd cylinder injector) back into the fuel injector pump with a small 4mm I/D pipe / hose. This should have been looked at and replaced during Test #6 when checking / replace the fuel hoses, but hey better late than never !.




The old spillover hose as can be seen above was fairly rock hard especially the ends. I don't blame it as where it is positioned is millimeters from the hot engine. After changing the hose and cleaning up the little fuel leak on the pavers, I took it was a 10km drive to give it a good run and leave it sit overnight.

Fingers crossed - Lets see how this does.

Mark

Sunday, July 6, 2008

Progress Report on Fixing Paddy - Test 12

Guys,

Today I went out to test Paddy's cold start issue and what a lovely frosty / misty / cold morning it was here in Canberra. Jumped in and cycled the glow plugs twice then kicked it the guts. Engine as usual started with no problems, I revved it to 1200 rpm. She started to run lumpy almost immediately, and just had time to race round and prime.

It then occurred to me when I was replacing the fuel hoses on the tank end I actually did not bleed the fuel system of air, simply primed it - Whoopsie another cold morning test wasted.

But soldiering on, I had read on the POCUK forum the following thread " Injector Pump " indicating another couple of possible causes regarding fuel tank end:

  • Fuel vapour check value /breather blockage - (Vacuum in a tank (because its not breathing) will draw fuel back out of the fuel system if there is ANY slight air leak on the pipework connections)
  • The fuel pickup pipes in the tank have been known to have an issue where the top end of the inner pickup pipes corrode and can allow air to be sucked in. Or the pickup mesh / filter is blocked or dirty. POCUK Thread - "Pajero cuts out when cold"
Let the testing continue:

12. So this morning having just bled the air out of the fuel system, knowing that I want to keep testing down to 1 thing at a time but at the same time not to waste another Cold Start. So I decided to look for the Fuel Vapour Check Valve. After a little looking I found the little bugger located behind a protection guard plate / cover at the rear passenger wheel arch.

After removing the mud flap (2 x 10mm, 1 x 11mm screws) and the protective metal plate (3 x 10mm screws) I found a fairly dirty looking object:






After inspecting the exposed (Atmosphere) end of the breather pipes it had mud caked outside and inside, nearly blocking the pipe, but from what I could see not blocking it totally.



After undoing the 12mm bolt that held the filter on the chassis, I then proceeded to remove the the hose clamp and hose of the pipe on the top of the tank as you can see in the above photo.



When I took the atmosphere end pipe of the valve, I blew through it with some resistance (not totally block) but then dirt shot out and the resistance was less and it was easy to blow through the hose. I tapped the hose several times to clean it out and to be sure ran water through it and dried it off.

I then moved onto the hose between the tank and the valve, when I blew through this hose, it was free of any obstruction and fairly clean.

Now the check valve itself, the next photo show what it looks like after you clean the dirt and mud of it. I was able to find the Part Number on the side of the filter: MB925886 and after a search on the web I found the matching description - "Checkvalve, fuel vapor control".

As you can see in the above photo of the fuel vapor check valve, there is an "arrow" which indicates the flow / install direction. In this case the arrow points away from the tank hence the vapor flow from tank out to atmosphere and allow air back in if required.

No sure of what test to perform on this valve, I simply blew into the end from the tank and with a little air nothing, then slight increase in pressure the valve opens. Blowing from the over end (atmosphere) I could blow easily with no obstruction.

So all appears to be correct, I put it together again and well have to see how it goes tomorrow morning.

That it for today fella's......

Mark

Saturday, July 5, 2008

Progress Report on Fixing Paddy - Tests 1 - 11

G'day Guys,

Having been reading a heck of a lot of forums and other documentation and learning alot of diesel diagnosing methods, symptoms and attempting to document what I'd learnt here in my blog in a more structured way I've been making my way slowly through the tests / diagnositics one at a time which has been very frustrating since you only have one attempt each morning to test the cold start since after the initial start issue the car starts and runs fine for the rest of the day, meaning you have to wait to the next morning. But I'm in no hurry as I want to eventually say for sure what the cause or possibly cause(s) have been.

To date I've done the following:

1. Bled the fuel system numerous times and especially at the start of the issue as I've documented in my blog. It helped for a little bit, but cold start issue came back after 3-4 weeks and bleeding did not help.

2. Drained and the water chamber for any water that may have been caught, ensured the water drain plug was securely tightened to prevent leaks. - No water and no joy.

3. Tighten all fuel hose connection clamps - No Joy

4. Replaced the Fuel Filter, making sure that the filter correctly sealed on the hand pump/primer (i.e. old seal not left behind) and that the water chamber / sensor had the seal correctly attached and tight - But still no Joy.

5. Attempted to look for air leak using clear Hoses on Filter 8mm input and output, 6mm return line. It was great to be able to see the fuel and what was happening during initial priming and engine running. During the initial priming and bleeding I could see there was a pocket of air about half the length of the hose from the filter to the injection pump. The only way to clear the lock was while the engine was running, to continue priming it, even when it got hard to prime, continuing priming and finally the the air pocket would just simply pass.






After this the car started for the next two mornings fine and did not stall. However when I took the car out for a test drive and got back, the air pocket would be back again. Putting it down to the size of the clear hose and not having the correct size host clamps to provide a good air-tight seal for the hose onto the pipes, but it was an improvement all over - Fingers crossed.

6. After some success from the previous test, I replaced the 8mm I/D Fuel hoses coming into and out of the FITLER and used new EFI hose clamps - but still no Joy.

7. Replaced the 6mm I/D Fuel host on the return line, including new host clamps. Initial cold morning start tests showed that Paddy would start and after little while start to run lumpy, but just like the very start increased the RPM for about 30-60 sec and the engine would run normal and no stall. It has been several months since I did not have to prime the fuel. Was I on a winner here ?

8. While priming / bleeding the air of the system after replacing the hoses, I could a high pitch squeal even now and then. I narrowed it down to the primer hand pump. When I wiggled the primer button, the squeal would appear to stop, but never start squeal. Thought that I finally had a sign of an obvious air leak hearing the squeal. What got me was that during the clear hose test, the fuel did not ran back into the tank. But I took the primer and filter of the firewall and took it to Diesel mechanic / specialist to have then test it under vacuum. When I dropped it off they said it would cost AUS$30 when I went to pick it up they told me the Primer / Filter was perfect andthey did not charge me for the test (Very nice of them). So I just saved myself $180-240 as a new Genuine Filter / Primer from Mitsubishi was $240 and after market one was $180.

9. After reading forums and other source regarding the HKT CP-05 glow plugs only lasting approx 12-18 months I decided to bite the bullet and replace the glow plugs with new CP-05's. I found the following PDF on the Delica forum - HOWTO Replace your Glow Plugs.

I tested each new glow plug and it heated red/orange hot with in 3-4 sec.

video


Took the old glow plugs out and tested them, most would take 7-8 secs to glow one even took near 11 sec and these were suppose to be quick glows.

video

Put the new glow plugs in and the next morning -4 degree C, in my eagerness I did a silly thing, I did not wait for full first cycle of the glow plugs, and so the engine started after the heating lamp went out (I should have known better and course swore at myself). The engine statrted but immediately ran lumpy, accelerator help a little but eventually stalled and shit loads of smoke. To add salt to the wound, a fucking kangaroo jumped out on me on the way to work and put a couple little dints on the right side. Fucking roos that the 2nd time Paddy has been hit by a roo.

10. Waiting for the next morning cold start I thought ok what next, so I decided to double check the glow plug power supply especially after the engine has started in case the glow plug module was shutting the glow plugs off prematurely during cold start. Next morning I had the multi-meter out and started Paddy (heating the plugs for 1 full cycle, and waiting a few secs after the 2nd heat lamp indicate went out) and pulled hand throttle on to bring RPM to 1500 to give me a little time before possible stall to get power readings.

After Paddy started and engine revved up to 1500 (poor thing, it did not sound good, especially not good at -4 degree C again), however I raced round put the multimeter leads on the glow plug busrail and negative terminal and I was reading 14volts, and I waited for sign of the busrail going to 0volts and the engine stalling. But the bloody engine did not stall, it did not even HICCUP. I scratched my head thinking WTF. This was the first cold start at below 0 degrees C that I have not had to prime her (Excluding the clear hose tests).

OK thought hard what had changed in the environment / startup procedure ? New Glow Plugs and properly heating the glow plugs. But there was no other difference except for I set the RPM immediately to 1500 rpm instead of 1000 RPM like normal.

11. This morning was only 0 degrees, and I heated the plugs normal couple of cycles, and started the car and let it rev up to 1000 rpm like I normally do. But before I could get reading the mulimeter the engine started to run lumpy. I took the voltage reading and it was at 14v so the busrail was getting voltage but the engine was running lumpy. not wanting it to stall, I primed it instead of using accelerator.

So Has it got anything to do with the RPM is 1000 rpm too low for a cold start ? I've got to wait for the next cold morning DAMN IT!!!!!

However I decided to delay the RPM test, after it nearly stalling this morning I replaced the fuel hoses and clamps at the fuel tank end. Lifting the carpet up to access the inspection panel in the boot of the Pajero I replaced the 8mm and 6mm I/D fuel hoses and clamps with new lengths of hose and efi hose clamps.

Image 1 - Carpet up and can see the inspection plate, remove 6 x 12mm bolts



Image 2 - Inspection plate close up.



Image 3 - Looking down through inspection hole onto tank. Can see the 8mm pipe left and the 6mm pipe to the right and what I assume to be the fuel tank guage wires and connector.




Image 4 - Looking through the inspection hole up towards the middle the car to see the other end of the hoses.



Image 5 - Job done, with the new fuel hoses and clamps fitted.




Lets see how Paddy starts tomorrow Morning. If it again runs lumpy and/or stalls I've still got the RPM test to do next and there are still a fair few more tests I've got to try which I've researched from the forums, but like I said, trying to elliminate one thing at a time and only getting one shot each day, I know it may take a while, but I'll get this little bugger sorted.

Stay tuned........

Cheers
Mark

Wednesday, June 25, 2008

Articles about Diesel Air / Fuel Leaks

  1. Land Rover Repair -> Freelander TD4 hard cold starts
  2. GM-Diesel Discussion -> GRRRRRRRR. Starting problems.
  3. Tracking down an Air Leak

As always the way, I've come across a great little GEM that pretty much has explained and summarised all what I was trying to capture here in my blog:


Hope you enjoy its information as I have.


Monday, June 23, 2008

Diesel Engine Diagnostic Tips PDF

Guys,

Just come across a very handy PDF cheat sheet describing Diesel Engine Diagnostic tips. Download PDF here.

Sunday, June 22, 2008

Glow Plug Information

This information was sourced from - "Winter Starting Tips" article and even though it related to VW diesels the information is fairly similar to all .

Two types of glow plug circuits were used on early and late model vehicles.
  1. The slow glow system was installed on early production vehicles;
  2. The fast glow on late production vehicles.

Always refer to the relay number for proper identification.

An incorrect match of fast glow relay and slow glow plug will result in premature failure of glow plug and/or relay.

To quick check the system, check the amount of current that is flowing to all glow plugs. A good specification to remember is fast glow plugs pull 12 amps each and slow glow plugs pull 9 amps each.

Listed below are some guidelines to refer to when checking fast glow plug systems.

  • 48 amps - all glow plugs are operating correctly.
  • 36 amps - one glow plug is defective.
  • 24 amps - two glow plugs are defective.
  • 12 amps - three glow plugs are defective.
  • 0 amp - all glow plugs are defective.

For slow glow systems use the following amp rating to test:

  • 36 amps - all glow plugs are operating correctly.
  • 27 amps - one glow plug is defective.
  • 18 amps - two glow plugs are defective.
  • 9 amps - three glow plugs are defective.
  • 0 amp - all glow plugs are defective.

The above specifications are applicable to four-cylinder applications. If you have more than four glow plugs, just add 12 amps for each fast glow plug and 9 amps for each additional slow glow plug.

NOTE: Depending on outside temperature, you may experience a surge of current up to 140 amps.

Engine Starts easy when cold but stalls after a short period.

1. Air Leak in Fuel Line / System

Diesels are very temperamental when air enters the fuel system.

Need to discuss / expand:

a. Fuel Hoses from fuel tank into Fuel Fitler and from Fuel Filter to Diesel Pump.
b. Sender and Return fuel hoses at the fuel tank end and how air leak can occur there.
c. Diesel Pump Return line/hose
d. Fuel Spill Over Pipe (small pipe interconnecting Injector spill rail back into the injector pump).
e. Bleeder screw on fuel filter / primer not sealing
f. Fuel filter not sealed onto primer
g. Fuel filter water sensor not sealed or the drain screw not sealing
h. Fuel Primer itself can be a source of air leaks via the hand pump.
i. Fuel Pickup pipe corroded within the tank can allow air leak
j . Fuel Pickup Filter and by pass can be blocked / dirty.

See my previous post "Air leak in Fuel Line / System".

2. Injector Pump

The injector pump has several seals that can and will perish over the lifetime of a diesel engine. However alot of recent failures with diesel engines has been caused by the reduction of sulphur in diesel down to 500 ppm and based on articles that I've read, it is being considered by the fuel / oil companies to reduce it further down to 50ppm. This is were its a little grey for me in that I believe that once you have the seals replaced the seals will be fine on 500 ppm, the failure is caused by the change in fuel mix environment where seals have been conditioned to the higher sulphur levels, but when the sulphur was reduce (less lubrication) it cause them to fail.


My understanding after reading articles is that when the pump seals perish, even though the fuel with in the pump is under a fair amount of pressure, you may not get any tell tale signs of diesel leaking from the pump. So if you inspect the diesel pump and can see a diesel leaking (or if the seals are truely gone - pissing) out of the pump then chances are this could be your source of an air leak within the fuel system.

There is one more seal issue that should be noted here and that is the BIG seal where the pump drive gear bolt together to the engine) that can allow diesel to leak internally into sump / engine block and allow oil to leak into the pump, allow oil to be burn upon a cold start up after the engine has been allowed to stop / lay for a while. Obvious signs to look for is if your oil level increases significantly and or you start find oil within the fuel filter and possibly injectors, you may need to cut open your old fuel filter and check it that way.


3. Possible Heating / Glow Plug Issue

With modern Diesels engine I've read about how they can with reasonable performance start with compression even at low temperatures. So don't overlook them as a potential source of the rough idle at start up. Remember that glow plugs are used to help start the engine but also to help initial running until the engine gets to a normal operating temperature or the max glow plug module time out.

Need to Expand on the following:

a. one or more glow plugs faulty or no longer effective

b. glow plug relay stuffed, hence preventing power to the glow plugs

c. Engine Sensors (i.e. temperature sender) may be stuffed or faulty causing the Glow Plug control module to prematurely shut off. Also the wiring between the sensors and the Glow Plug Module / Control.

d. Glow Plug Module / control itself could be faulty (i.e. capacitor controlling the timing circuit are a known issue on the Pajero's).

e. Depending on your Glow Plug system you may have two Glow plug Relays such as that in the Pajero 2.5ltr has a 12v for initial heating and star then a 6v relay for initial running.

f. Poor wiring / electrical connectivity between relay and glow plugs.

g. Busrail / bar in poor condition hence not providing glow plug with current to heat up.

h. Wrong glow plugs for the vehicle.

Engine Starts easy when cold but run lumpy for short period then runs fine.

1. Air leak in fuel Line / System

This is a possibility, but since it does not stall, the leak or amount of air in the fuel system was small and engine is able to cope albeit very lump.

Please read the following "Air in Fuel Line / System" for more details from my previous post.


2. Glow Plug System Faulty

If one of the glow plugs if faulty or the power supply to glow plugs is faulty then this could cause one or more of the cylinders to run cold and cause the engien to run lumpy until the cylinder reaches operating temperature / condition.

Please read the following "Glow Plug System Faulty" for more details from my previous post.

Engine takes a fair bit of cranking to Start when Cold, but eventually starts.

1. Fuel Supply

With this particular cold start issue, a possibility could be related to the diesel fuel waxing up during cold temperatures caused by the fuel not containing winter mix / additives, or its does and its even more colder than the winter mix is designed/produced for.

If your symptoms is not occurring frequently and only during very cold conditions, then this could be a possible cause. The remedy is to ensure that when you're entering cooler / cold conditions such as ski fields / alpine regions that you have filled your fuel tank up with winter mix.

Another scenario is outback Australia were its get fairly hot during the day, but bloody freezing at night, in this case none of the fuel outlets will have winter mix, and so to rememdy this you go to a local auto store or fuel station and pick up fuel additive ensure that you add to the tank when you expect these conditions are about to occur.

-=-=-=-=-=-=-=

A subject to discuss and expand on is when you don't have access to winter mix / fuel additive is the use of a small amount unleaded petrol to help prevent waxing. I've read a few articles and they state pros and cons of doing this. Please until I've fully understood it myself do your own research and if anything lock it away as an option if absoloutely needed when you are unable to obtain winter mix / additive and there is a change you're about to encounter cold condition and you fell you diesel will wax.

-=-=-=-=-=-=-=

2. Low Compression

As expected with diesel engines the fuel is ignited under the correct compression ratio and heat. If one or all of your cylinders are starting to experience low compression, then this could make it harder to start a cold engine.

I found the following article - "Compression Test" useful for detailing Compression Tests on both Petrol and Diesel engines.

3. Air in Fuel Line / System


There are a few causes that may cause air to enter the fuel system.

a. Fuel Hoses - There are a few to check / replace

  1. Input and Output fuel hoses of the Fuel Filter / Primer (8mm I/D)
  2. Return Fuel Hose (6mm I/D) from Injector Pump to pipe back to the tank.
  3. Sender (8mm I/D) and Return Fuel (6mm I/D) Hoses on the Tank End.
  4. Spill Over / Fuel Leakage Pipe (small pipe from middle injectors back to injector pump).

These hoses can perish over time. This could lead to air entering the system and you may not even be able to find the crack. It only cost about few bob per meter of fuel hose worth the investment and piece of mind nothing that you've done them.

The other part to this one is the fuel hose clamps, make sure they are secure / tight proper hose clamps (smooth inner bore) not standard jubilee clips that will tear / pierce into the host



b. Clogged Fuel Filters

Obvouiosly this can affect performance of a diesel engine, and eventually hinder even stop a diesel engine. Make sure you replace fuel at the specified km's / interval.

c. Water in the Fuel / Fuel Filter Water catchment full

Water in the fuel system can affect the performance of a diesel engine, cause it to stall and if large enough quantities kill the engine (ie water in via the air intake).

The fuel filter water catchment chamber that collects water from the fuel system may be full. Normally fuel filters have a water sensor that screws into the buttom of ther filter which will alert the drive when the chamber is full or nearing full. But this should normal not occur between regular fuel filter replacements unless you have encounter a very dirty source of diesel or water has contaminated the fuel tank some how.


d. Fuel Water Sensor leak

The water sensor that screws into the buttom of the fuel filter should always have the o-ring / replace before being screwed into the filter. This ensure that leak are prevented. However leaks can still occur if the plug is not total and securely screwed into the fuel or worse and shamelishly the water drain plug is not tightly shut off /screwed on.

e. Fuel Filter / Primer leak

The fuel filter seal onto the primer may not be air tight. Each time you replace your fuel filter you should make sure you add a little oil / fuel on the new seal of the fuel filter before screwing it back on to ensure a good air tight seal.

The Primer pump itself can be a source of air leak.


f. Fuel Pickup pipe corroded within the tank can allow air leak

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g. Fuel Pickup Filter and by pass can be blocked / dirty.

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4. Engine Block / Sump oil Heating Unit Failure

Depending on were you live and the weather condition you experience, vehicle come with or have aftermarket block heaters fits which plug into mains to heat the engine sub oil and block to enable diesel engines to start easier / possible. I've have no experience with these units but can appreciate that they can and do break down. And when the breakdown your engine maybe next to impossible to start without the vehicle being kept in a warm area.

5. Glow Plug System Faulty

The function of the glow plug is to heat the cylinder area to help diesel ignite inconjuction with the correct compression ratio. It usally comes down to glow plugs for a diesel engine having trouble starting cold. There are a few components within the Glow Plug System that could fail causing the failure to correctly heat the cylinders during a cold start.

a. Faultly Glow Plugs - Short / Open circuit

When testing Glow plugs, I've read there are two typical faults that occur with the glow plug itself (Open / Short Circuits).

You can test glow plugs in situ, however only for Open Circuits. To test glow plugs in situ you will need to remove the interconnecting powe bus bar / rails connecting each glow plug else if at least one of them working the test would always work. Once you have the bus bars off, if you use a test pen / lamp and connect one end to the positive terminal and then touch the tip of each glow plug, if it lights up then the circuit is complete and the glow is allow power through it.

However if there is a short with in the glow plug then the previous test will work, but because there is now a shorter path for the current to travel the plug will not heat up.

The best test is take them out and visually inspect them but applying power. To save me a bit of time, the following articles are brilliant source of information about glow plugs and how to test them. Even though its targeting VW vehicles, majority of the concepts are shared amongst all diesel engines:

VW Diesel Glow Plugs
VW Diesel / Glow Plug System
VW Diesel Glow Plug Control Circuit

One important bit of advice from these article I got and that is you should always test NEW Glow Plugs, just because they are new doesn't mean they are not faulty.

Here are some You Tube videos, the first one is current proedure for testing glow plug, the second video, well lets just say I wouldn'y advise it, but its cool to look at :).

Video 1 - VW Rabbit pick-up diesel glow plug test
Video 2 - Glow plug test

b. Incorrect Glow Plugs for the engine

I've read of instances where people have incorrectly put glow plugs for the Turbo Diesel Intercooler engine into a Natural Aspirated Engine causing it to be a very hard start. The other scenario is putting 12v Glow plugs into 6v systems meaning the glow plugs don't heat correctly.

Another common fault I've read about is that of "false ecomony" were people have experienced the hassles of purchasing cheaper brand of glow plugs but only to find out they are fairly short lived and start playing up.

Please consult the catelogs and look for the glow plugs for your vehicle and engine type (ie Turbo, Intercooled). Also stick with the tried and tested brands of glow plugs.

c. Poor or no power supply to Glow Plugs

There are a couple of places along the glow plug power supply line that could cause problems.

First test is to perform is to see if you are getting power to the glow plugs. This is fairly straight forward in that using a multimeter on DC volts mode you put the negative probe to the negative terminal or a good ground source on the chasis. Then put the positive probe on the 1st glow plug. Have someone else turn on the ignition to warm the glow plugs and you should see 6v or 12v depending on your vehicle for about at least 10 sec (even after the glow plug dash board indicator has went off). Repeat this for each glow plug.

Even if you are meauring correct voltage there could still be an issue with the power supply in regards to poor connections or faulty wiring which prevent the correct amount of current to be supplied to the glow plugs. Remember that glow plugs on average draw upwards of 36/48 amps depending on number of cylinders and voltage 6v or 12v - see here for more.

Second test to perform is to trace / check the wiring to the glow plugs, look for poor connections from battern to glow plug relay and then onto the first glow plug. Make sure now of the connections have corrusion and are tightly secured and making a good connection. With the pajero and many other diesel egines, the power is wired to the first glow plug and then distributed to the other glow plugs via a power bus rail (several metal strips interconnecting each glow plug. Each of these connections need to be checked and cleaned securely bolted to the glow plugs.

If this has resolved your issue, the next test to check for faulty glow plugs see previous section.


d. Malfunctioning Glow plug Control Module / Relay

If even after checking the glow plug power supply (fuse, wiring, power bus bar/rial) and assuming you have a good battery then it starting to indicated that your glow plug control module and or relay is stuffed.

The easiest way to test this is power / jump the glow plugs manually using a length 6mm wire with appropriate connection to bolt to the first glow plug and run to the positive battery. If you clip it on to the positive and wait say 10 seconds and then attempt to start the car.

If this resolves your troubles and the engine starts, then you will need to look at replacing the glow plug control module / relay or if that looks like its going to be too costly, I've read articles on how people have installed a proper manual power circuit to power the glow plug manully from the vehicle's dashboard. Please read this article - "Pajero Glow Up"


6. Injector Pump

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7. Injectors

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Types of Diesel Cold Start Issues

After researching diesel cold start issues for diesel engines I've come to understand the following common set of symptoms encountered during a cold start:

1. Engine takes a fair bit of cranking to Start when Cold, but eventually starts.

2. Engine Starts easy when cold but run lumpy for short period then runs fine.

3. Engine Starts easy when cold but stalls after a short period.

4. If your are unlucky you could experience combination if not all of the above scenarios :(


But depending on your cold start symptoms will depend on which tests you could perform to narrow it down or correct the issue.

I'm sure there are a few more symptons that exist, and if you have these symptons let me know, and more preferably provide solutions on how you diagnosed your symptons to fix the cold start issue.

Description of My Diesel Cold Start Issue

Paddy (Thats my Pajeros Name) developed its intermitting cold start issue around Feburary 2008. Its inital issue was that it would start pefectly but after about 10 - 20 sec the engine would run "lumpy" like one or more of its cylinders was not getting fuel or heated enough, and there was moderate amount of smoke coming out the exhaust. With a little increase of the engine RPM to about 1500-2000 the lumpiness would work itself clear and the engine would run fine. Once the car had past its first start of the morning, ever other engine start was perfect and no sign of the lumpiness.

But the intermitting issue became more persistant (as anything would do if it does not get fixed) and eventually even upping the RPMs to 2000-2500 would not help and the engine would simply stall and there was a shit load of smoke coming out of the exhaust during the lumpiness. The restart would take a fair bit of cranking, once started a little lumpy then all was good.

I jumped onto the Pajero 4WD Club of Victoria Forum and started the following thread "NJ TDi 2.8 Strange Start issue" This thread started expanding my knowledge of diesel cold start issues alot. After some very help advice, I followed some advice regarding air in the fuel system and I bled the system the cold start issue disappeared. And so let my guard down and thought I had won.... but only after about 3-4 weeks, it came back with avengence.

During my initial investigation when trying to work out what was happening I decided to do the following test to see what would happen. I started the engine and raced round to the fuel filter / primer and just as the engine started to run lumpy I pumped the primer a few pumps and the engine ran smooth. Then starting lumpy again so I repeated this process 6-7 times and then the engine ran fine. And as usual all other engine starts during the day, the engine started and ran without any hiccups.

This same initial test was the only process that would stop the Pajero Diesel enigne stalling during cold start so it meant I still had an issue with my fuel system. This started me down my path of researching and attempting to gain a better understanding of diesel fuel systems.

Please bear with me as I start doing a brain dump of what I've learnt and think I've understood. Then I'll start to expand on each sympton and tests and details as I have time. Over time with with your feedback, hopefully we'll have a nice little knowledge repository top cope with "Diesel Cold Start Issues".

Pajero Cold Start Issue Introduction

G'day All,

Well if you are here you are most likely researching for solutions / symptoms regarding the nortorious Diesel Engine Cold Start Issue. As you will know, this issue is not just specific to Pajero's. Actually all diesel motors will experience cold start issues at one time or another.

Earlier research on a number of forums indicate that it is a notorious Injection Pump Seal issue that the Pajero 2.8 Diesel experience. But there are a fair number of other causes documented as well. So Instead of me jumping to the conclusion that its the seal, the purpose of this blog is to document my research and knowledge I've gained while diagnosing my Pajero's Diesel Cold Start problem.

If you, while on your search for anwsers, find any information you think should be added here to help others please let me know :)


The Legal Stuff:

Before we get started or too far into all the fun, this information is by no means the word of a Qualified Mechanic. I'm bar far a Qualified Mechanic, I'm just a simple bloke who is not afraid to get his hands dirty and tinker with electrical / mechanical objects as long as I have a reasonable manual, guide / HOWTO.

So please make sure that you understand that anything said in this blog, by me or anyone, that you accept that myself and anyone else that posts information on this blog do not take responsibily or liable for any damage that this information may cause to yourself or engine / vehicle.