GU 2.8TD - Starting Problem Resolved
Submitted: Saturday, May 08, 2004 at 17:14
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Member - Hugh (WA)
Hi Forumites,
There have been a number of posts discussing problems with starting GU 2.8TDs, namely continued cranking post glow plug light going out - particularly when engine is warm. Some excellent
feedback also, with some common issues being 1)a mod to fuel pump (fitment of shim to take up tolerance shift when pump is warm), 2) glow plugs, and 3) battery on the way out (despite plenty of cranking power). Perhaps others too - the above from memory.
This problem has been bugging my GU for the past 2-3 months. I wasn't keen on spending $ on a pump mod so spent some time diagnosing the issue. Glow plug resistance was OK so I didn't think they needed replacement. I found that if I left cranking until a while after the glow plug light went out the engine started OK. Reading manual shows that glowplugs are heated for a fixed time, pending coolant temp i.e. less heating time if engine is warm. Also, the glow plug light is only on for a short fixed time and glow plugs continue heating for sometime after. Also note that the glowplug circuit is only on for a finite time i.e. if you leave key-on for ages then crank the engine won't start because glow plugs will have cooled down.
So this made me think it was an electrical supply issue. I never did measure battery voltage though suspect it must have been low, hence needing longer time to get heat into the glow plugs. The battery seemed to be in good health with plenty of cranking power so I was beginning to think it might be the pump.
Well so I thought until the battery died during the week. Fitment of a new battery has solved my starting problem. The engine now starts when cranked directly after the glow plug light goes out. Also noted that cranking time to first fire is markedly reduced.
So thanks to those that have posted about the battery being a potential root cause - it was for me.
I thought I would post this for other people's information. I note that the new GU III 4.2TD has an electronically controlled pump (similar to 2.8TD). Owners may wish to make a mental note in case similar symptons occur.
Regards,
Hugh
Reply By: Member - David C (QLD) - Saturday, May 08, 2004 at 17:46
Saturday, May 08, 2004 at 17:46
Hi Hugh,
My 250,000 km GU 2.8 had the same problem and it was fixed with the new plate/shim on the fuel pump. $40 from Motsons or about $80 for them to fit (15 minute job). I can now start like a petrol without waiting for the glowplug light (I don't do this but you now can if you want).
Regards
David
AnswerID:
57745
Follow Up By: Member - Hugh (WA) - Saturday, May 08, 2004 at 21:05
Saturday, May 08, 2004 at 21:05
Thanks for the follow-up David.
I assume from the minimal fitment cost that installing the new shim is quite straightforward and likely with pump in-situ. I was expecting this to be a lot more expensive, but it seems to be worthwhile doing if I can do it myself.
I'll contact Motson's and find out all about this. Do you know where abouts on the pump that the plate/shim is fitted?
Regards,
Hugh
FollowupID:
319524
Follow Up By: rolande- Saturday, May 08, 2004 at 21:46
Saturday, May 08, 2004 at 21:46
Hugh,
As per David, I have recently had the plate fitted, it is simply a "thicker" version of an original part on the pump. It is an odd-shaped plate with a O-ring in the centre and two holes for screw fitment. As i did not fit myself I can't tell you exactly where on the pump it is, but my mechanic said it was straightforward without any directions as to how/where so i would assume anyone with some knowledge of the pump could do it themselves. My mechanic was also a bit sceptical about this simple fix. I asked that he fit the plate and do nothing else - then give me a reply - "Yes, it does seem to start a lot easier now".
i must add that the difference is not small, it is quite pronounced, as David says, it starts like a petrol now. The solution about waiting for a few seconds after the glow plug light goes out seems to give the pump more time to build up pressure to fire the engine, with the plate fitted it supplies enough pressure almost instantly. Cost me $55 posted O/night to my door from Motson's in Beudeasert, phone number on the website.
Rolande
FollowupID:
319525
Follow Up By: Member - David C (QLD) - Sunday, May 09, 2004 at 08:00
Sunday, May 09, 2004 at 08:00
Sorry not too sure where the plate is actually fitted. I have a friend who will be getting one shortly and doing the fitting themselves so I will try and get the instructions that come with the plate.
Regards
David
FollowupID:
319561
Follow Up By: rolande- Sunday, May 09, 2004 at 21:02
Sunday, May 09, 2004 at 21:02
David,
It may be helpful to your friend if they write down the instructions over the phone from Motson's as no written instructions are included
Rolande
FollowupID:
319649
Follow Up By: Nino & Kerry (VIC) - Sunday, May 09, 2004 at 21:47
Sunday, May 09, 2004 at 21:47
Hi Hugh.
I posted on this subject about two months back under the name of EX7RHA. Had the same problem with
mine. I bought the pump cover/shim from my local dealer. It cost $16.54 +tax and the part # for the "o" ring is 16826-V0700. I don't have the part # for the cover any more but Nissan will be able to cross referance from above #.
It is fitted in about 10mins and go's on the outter side of the pump as you look at it from the O/S/F guard ( between the pump and battery ) If you decide to fit one make sure you use only a little Vaseline on the "o"ring and Never use Silicon sealant as this WILL stuff the pump if a little gets in the pump.
As a side note in regards to your glow plugs. If you are useing the
Gregory's manual No512 (GQ 2.8) Ignore it, the GQ is wired differently to the GU.
Cheers Nino.
FollowupID:
319653
Follow Up By: Member - Hugh (WA) - Monday, May 10, 2004 at 00:09
Monday, May 10, 2004 at 00:09
Thanks Nino,
I don't have a manual for the pump but do for the Y60 RD28T engine (factory supplement - GQ). Even though there are differences, the GU pump body looks the same in this region. The cover I think you refer to is a cover for the timer piston (on a GQ anyway). Manual talks about adjusting shims for correct pre-load of a spring to get correct timer piston stroke at various pump speeds (controls injection timing I think). Unsure how this differs to GU with electrically controlled mechanical pump, but if principle is similar then I assume the fix is all about increasing the spring pre-load and likely stroke. The manual mentions shim size from 0.1 to 2.0 mm thickness.
Perhaps there may be some diesel pump technicians out there who can comment.
Thanks too for the note about glow plugs. I find this out after looking for the GQ style system, to then discover the glow plug circuit is same as for GU 3.0L (per
Gregory's manual 512).
Regards,
Hugh
FollowupID:
319667
Follow Up By: Member - Hugh (WA) - Monday, May 10, 2004 at 00:12
Monday, May 10, 2004 at 00:12
Slight typo - the GU 3.0 manual is
Gregory's # 519
Hugh
FollowupID:
319668
Reply By: Diesel Do - Sunday, May 09, 2004 at 18:32
Sunday, May 09, 2004 at 18:32
Thanks for the
feedback Hugh. Appreciate it very much.
Interesting problem this. Does anyone have a suggestion as to why a new battery fixed my (and Hugh's) problem, and yet a shim on the fuel pump can have the same effect? I'd be very interested to find out if an "old" battery (same as Hugh and I had) will still start the engine easily if the shim is installed? Can't think how to
test this unless you actually have a starting problem that is fixed by the battery, and at the same time be able to install the shim. Any ideas?
Seems to me that when the battery reaches a certain undefined age/condition again both Hugh and I (and possibly others) will return to having starting problems. Just a thought - is there any chance that the starting problem was fixed when the battery was replaced simply because the computer was powered off for the first time (possibly ever)?
Anyone - is there a mechanical explanation please?
Regards,
AnswerID:
57872
Follow Up By: Member - Hugh (WA) - Monday, May 10, 2004 at 00:20
Monday, May 10, 2004 at 00:20
Thanks for the comments DieselDo. I am going to look into this a little further. From what I have read today, I think that the shim is adjusting pre-load on the injection timing piston. I need to do some more fact finding but I wonder if, being an electrically controlled mechanical pump, that pump timing may be affected if voltage is lower than ideal. Could be an electrical/mechanical interaction, solved by either - perhaps.
Only some thoughts - I'll see what I can find out and let everyone know.
Hugh
FollowupID:
319669
Reply By: gumagoo93 - Monday, May 10, 2004 at 08:20
Monday, May 10, 2004 at 08:20
My GU2.8TDi suffered from starting problems a couple of years ago....problem as it was explained to me is the cylinder lining of the delivery piston is too soft....I purchased & fitted the thicker plate, but the pump was too far gone...ended up sending it to Melb (i'm in
Darwin) for repair....expensive, but what good is a vehicle that won't start!.....from memory the plate is low down on the road side of the pump and is held by 2x10mm bolts....
AnswerID:
57934