Car choking under high RPM

[patto1234]

Had a problem which has been going for a couple of months and is starting to annoy me. When i put my foot to the floor and the car revs really hard sorta towards the limit before I need to change gear the car starts to lurch forward and just choke. Usually the car will just keep going and going nice and smooth and continue to rev high. But lately it just keeps doing this. It is seriously affecting the performance and quality of the car's ride.

[Fitzpatrick Speed Works]

what plugs are in the car and whats the gap????

[race_snooze]

coil packs as well check out this http://www.skylinesaustralia.com/forums/sh...ead.php?t=32356

[patto1234]

what plugs are in the car and whats the gap????

I honestly don't know...im pretty sure its all factory. Whether that helps or not?? So could it be a sparkplug problem? or is it something else?

[MANWHORE]

Pat. It's chris mate.

1. check sparkies. cheapest and first thing to check. I'd recomend the bcpr6es (copper ngk). Stock r33 gtst is meant to run the 1.1 mm gap and 5 heat range. because yours is running exahust, boost etc, run the 0.8 gap and the 6 heat range.

2. coilpacks. Due to the location of the coilpacks right above the engine, they get very hot. They are, believe it or not made out of plastic, and the plastic cracks over time. Pull the coilpacks out and check for cracks. When I say cracks, I don't mean like massive ones. They form hairline fractures. Also check for burns on the plastic, because this may indicate that they are cracked, and the sparks are leaking out. (As said in 1. by running a 0.8mm gap spark gap, this can reduce the effect of warn coils. Reason? The spark will jump to the easiest place possible. If you run a larger gap like 1.1mm, it may be easier for the spark to jump out the edge of the coilpack through a crack).

3. AFM - you're running a hks pod which is oiled. Pull the pod off, and rub your finger on the black plastic inside the AFM. you'll probably notice your finger will be black. I did on my car, and it was. Solution? Contact cleaner from Dick smith. spray the shithouse out of the AFM element and watch the black stuff run out. (hehee, I suggested to do this last time).

4. How much boost are you running? when the stock ecu senses too much air flow, it goes oh shit, because stock, they're only meant to run 5/7 psi. It richens the fuel mixture and severely retards timing. It sorta feels like you've hit an invisible wall. It's quite violent. I found on my car that it started happening at about 11 psi (with full exhaust, pod, cooler, etc).

You'll have to take me for a fang to show me what it feels like, because if I remember correctly, you were running about 10psi. This is about borderline for rich and retard because you don't ahve fmic (stock ic then becomes quite restrictive as you increase boost).

Obvious things:

1. are you running good fuel? ultimate?

2. have you had your fuel filter changed recently? your car might be leaning out due to lack of fuel from a clogged fuel filter. unlikely though.

3. tried resetting the ecu? some notice it does something, others don't. I do.

4. how old is your cat convertor? is it blocked? quite unlikely though.

5. any vaccuum leaks anywhere? like any dodgy arse looking old hoses anywhere?

hmm... that's all I can think of atm. I just got back from work...zzzz..

Cheers

[ZigenGT]

Great post by 97r33gtst-typeM