Problem That Wont Die! Please Help

[joeleo87]

hey all

im really hoping i can find some help here coz im out of ideas and i cant keep driving my car waiting for it to die, then toe it

first time the car cut out it lost revs, i couldnt accelerate (non responsive) and the car stalled while i was driving. restared fine but took a few seconds for the accelerator to work again. week later it cut out and started but was spluttering and coughing then stalled (but then started fine, several times). days later it stalled and did not start for 30mins (twice).

all times the car had only been driven for about 20mins. but car was warm in that respect.

things ive done to fix the problem.

-fuel filter

-reconditioned AFMs

-CAS and ignition module been bench tested. (by auto elec)

-conections cleaned.

A few mods on the car - cat back zorst, mines ECU.

the problem hasnt re occured since ive been out of the auto elecs (3 hours) but im sure it will happen again soon.

any ideas personal experiences would be much appreciated.

[GTRsean]

Last year, I went for a drive and on my way home turned a corner and car spluttered then died.

It was so hard to start and I had to pump the pedal just to get it to splutter and not even idle.

In the end it was narrowed down to the fuel pressure bypass check valve thats in the tank. It's located on the outlet line from the pump.

It was bypassing fuel for no reason, so the engine would barely run. It could fail intermittently...

Could also be that ecu of yours...

[arbess]

dying fuel pump possibly. usually a dead fuel pump... you have no control of the car.

something else in the fuel line? low pressure?

[joeleo87]

you mean the brass fitting on the line? it looks in working order.

i have heard nothing good about the mines ECU so its got me worried :S

i dry fitted a fuel pump in it not long ago and the stock pumped looked in good nick.

can some1 clarify how to check fuel pressure?

Edited September 10, 2008 by joeleo87

[babyskyline]

If you can get your hands on a stock gtr ecu then you can try that and rule that problem out.

My 32 was doing a similar thing and turned out to be a dying fuel pump but it can be tested by a mech with a simple pressure guage being put into the line and seeing what happens every time it plays up.

[GTRsean]

Depressurise feul system.

Hook up a fuel pressure gauge to the fuel pressure hose from your fuel filter.

Turn ignition on, you should see pressure go up when pump primes.

[joeleo87]

ill buy a pressure gauge tomorrow.

the thing with the ecu is ill need it for at least a week to test it completely

and god damn that fuel filter is right shit to change lol

[joeleo87]

What should the pressure show on the gauge?

[GTRsean]

43psi when it's connected into the fuel line (using a tee fitting) ignition on.

36psi at idle.

43psi with vac line to fuel regulator removed

[shortcropblonde]

Is your idling rpm unstable at times? If is, then is most likely to do with a dirty AAC valve. You need to open it up and clean it and adjust the idle screw accordingly. There is a DIY on the forum on how to do this. Just search aac valve.

[joeleo87]

so ive had my car back for 1 day now and already i know the problem is stil there

on my way home i noticed a massive decrease in power, almost like the accelerator was heavy??? best way to describe it anyways.

im getting a fuel pressure kit tomorrow so i can test the fuel pump.

the ECU and Fuel pump are the only things i have left to change out. im hoping its the Fuel pump?

just to clarify though. if the fuel pump has shit all pressure would this throw the CAS off??? because when i died 1 night i called the RAA and he did the light bulb thingy on an injector plug and said the CAS must be damaged because there was no pulse BUT i had the CAS bench tested and it is fine???

Some give me some answers please!

[bludger]

Mate im having pretty much the same problem i think its the ecu as my car is being looked at now

[RRB20ASH]

i have a similar problem, when I excelarate it goes okay fo a bit then stops ut doesnt stall then goes again. like it is spluttering.

what i did was i replaced the coils and that actually worked... it stopped it unfortunately for only 1300ks now its back. so i dunno what it is either. my friends think its he fuel pump i was thinking air flow metre but i got that checked. so i dunnooo.

[bludger]

I think if its idleing funny and about to stall its also got something to do with the bov's as my gtr has none and is also idleing funny and im pretty sure thats what it is.

[45ULT]

rrb20ash yours sounds like the wrong heat range or incorrectly gapped spark plugs if the coil packs fixed it for a while. as for the gtr's id be checking your bypass valve in the tank as previously mentioned. because if it was the fuel pump it would have shit itself by now instead of doing it every now and then. although they take a while to die once they start cutting out completely there's not long left in them.