Landcruiser 2002 HDJ100R fuel pump?

Submitted: Thursday, Feb 20, 2014 at 07:56
ThreadID: 106334 Views:4369 Replies:4 FollowUps:1
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My vehicle idles smoothly but is jerky under mild acceleration, particularly when cold. (Feels just like bad spark plugs on a petrol engine.) Goes well under full power though.
My mechanic believes the problem may be in the fuel pump, but it has to be off the road for a week or so to have it diagnosed ( in Adelaide?).
There is also a secondary problem, may be unrelated but started about the same time. There a loud turbo whistle under load, which may be a hole in the inlet manifold gasket behind the pump.
Any suggestions, anybody?

Barry
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Reply By: Ross M - Thursday, Feb 20, 2014 at 09:20

Thursday, Feb 20, 2014 at 09:20
If you have a turbo whistle, then it would seem there is a leak of turbo pressure somewhere.
As the throttle is opened the engine will increase fuel but the leak is draining some of the expected turbo air away from the engine.
As you accelerate the turbo air delivery quantity will be far more than needed and the injected fuel will burn normally.ie good power.

I would be finding the source of the turbo whistle FIRST before anything else.

A piece of garden hose to your ear and the other end as a, "search the engine bay diagnostic tool" will should quickly find the source of the air leak.

It may not be pump related at all.
AnswerID: 526852

Follow Up By: pop2jocem - Thursday, Feb 20, 2014 at 12:21

Thursday, Feb 20, 2014 at 12:21
Could be coincidental but as Ross said, eliminate the turbo whistle/leak first and see if that helps.
Personally I would have thought that the leak if significant enough would have affected the power under full load. Usually the small leaks make a heap of noise but do not loose enough boost pressure for the power loss to be noticeable. Significant boost loss will affect the operation of the fuel limiting device that stops excessive smoke on hard acceleration and also reduces performance.

Cheers
Pop
0
FollowupID: 809244

Reply By: John and Regina M - Thursday, Feb 20, 2014 at 10:20

Thursday, Feb 20, 2014 at 10:20
Yes sounds like a hole and the injector pump is on the way out. Tolerances are tight and a worn pump usually manifests itself as rough acceleration.
AnswerID: 526861

Reply By: Member - Phil G (SA) - Thursday, Feb 20, 2014 at 22:41

Thursday, Feb 20, 2014 at 22:41
I'm guessing you have a blocked catalytic converter. The flange between the dump pipe and exhaust is sprung and under pressure will let out exhaust gas.
I had exactly that happen to my HDJ79, and the exhaust on the HDJ100 is the same.
There's a write up here.

If it is the problem, the best solution is to fit a 3" exhaust with no cat, and disable the EGR valve as per the article.
AnswerID: 526905

Reply By: BarGan - Friday, Feb 21, 2014 at 18:42

Friday, Feb 21, 2014 at 18:42
Thanks for your replies guys.

I revisited my mechanic today and fortunately, juts before I got there, the LC died with engine light on. The mechanic put his scope on and found a logged error indicating problem with the accelerator input. Then he suggested isolating the cruise control and found that this would require rewiring the plug (back to original). I booked the LC in to have this done. On driving out of the shop, I found that all of the roughness was gone!! Apparently, he had wiggled the connector above the accelerator and this has fixed the problem, but maybe only temporarily, so he will check this next week. Anyway, much cheaper than having the pump diagnosed!!
Regarding the whistle, this has been found to be definitely the inlet manifold gasket, so this will be replaced next week also.
Thanks again for your advice.

Regards
Barry Gange

AnswerID: 526974

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