Car Problems

[Wogan]

Hey,

I made a couple posts in the "car not accellerating propperly" thread, but still having problems with my car. It's a 1990 R32 gts-t

Here are my current modifications:

pod filter

3" cat-back exhaust

FMIC

Here is my problem:

When the car is hot, if i accellerate hard, the engine pops and misfires at about 3500rpm. Only happens under load and only when i've been driving for about 5 mins or so and it's nice n warm.

Here's what i've done so far to try and fix it:

Upgraded fuel pump to one from an R33 GTR

New spark plugs

Replaced coils with 2nd hand ones from another 32 gts-t

Not sure what's going wrong.. seems like it's a fuel or ignition problem, but i can't quite tie it down. I put in a fuel mixture display kit from Jaycar to see if it was rich or lean when it spits n pops, but the lights just flash from lean to rich and back over n over again.

I'm pretty much out of ideas. Maybe i need to upgrade coils. Maybe i should try regapping the spark plugs.. i really don't know anymore.

Any advice or suggestions would be greatly appreciated. May end up that i'll just have to take it to a garage with a dyno to get it diagnosed. better start saving my $$

[gazza750]

decrease the plug gap if that helps its time for a good set of splitfires

[Pal]

maybe boost cut???????

[Wogan]

boost is fine.. actually a little higher than i expected.. gettin about 12psi

maybe the fuel pressure regulator?

[Wogan]

put in an autotechnica fuel pressure regulator.. i don't recommend them.. crappy cheap parts, broke in a couple places, but managed to get it working in the end.

fuel pressure was only 35psi when idling.. upped it to 60psi at idle and seems to have fixed the problem.. more testing (aka fanging it) needed, but signs look good.

Thanks Gaz n Pal for the suggestions.

[Pal]

glad to see u got it sorted

[Wogan]

well more testing has been done and the problem is still there..

gonna try aralditing the coils and reducing the spark plug gap... hopefully that can help.

[gazza750]

could also be the ignition module

[bubba]

+1 for igniter if it's happening with heat and you've already tried another set of coils.

[Pandaah32]

try a new air flow meter.....

my afm was dicky when the car got hot and i did all the usual 'obivous' quick fixes such as

-changed my igniter module

-changed all 6 coilpacks

-put in new plugs and gapped them to .6mm

-changed air filter and changed fuel filter

problem ended up being the air flow meter was faulty.... give ben at KYP a call

Edited December 5, 2007 by Pandaah32

[Wogan]

thanks.. i'll be looking into all these options

[Steve621]

I recon you should buy a 34 and get rid of all your problems..

[Wogan]

hahaha.. maybe you can donate me the cash mr engineer sir.

but yeah.. me n Steve found tonight that my coils are arcing onto the block seems the "new" coils were about the same condition as the old ones. gonna araldite them and reduce the plug gap.. should do the trick.

[bubba]

I've got a set of standard 32gtst coils doing nothing other than taking up space.. they were working well enough to make 245rwhp on the RB20

Or a set of splitfired aren't too pricey, I got mine for $515 delivered I think it was.

[Wogan]

ok this is really annoying me now.. problem is still happening with araldited coils and spaller plug gaps.. gonna try air flow meter next.. Were you getting the same symptoms when your airflow meter was faulty Pandaah?

next to try after that will be ignition module.. how do i go about testing that?

Edited December 8, 2007 by Wogan

[Wogan]

another thing i find interesting is that my car is making about 12psi of boost without a boost controller installed.. inspected the wastegate actuator and the hose feeding it, but they seemed fine. The previous owner hadn't done much work to the car and didn't have a working boost gauge.

could it be that i'm getting too much boost and the standard ECU is cutting the fuel?

[gazza750]

ok this is really annoying me now.. problem is still happening with araldited coils and spaller plug gaps.. gonna try air flow meter next.. Were you getting the same symptoms when your airflow meter was faulty Pandaah?

next to try after that will be ignition module.. how do i go about testing that?

borrow one from someone else or throw it on a dyno for a full diagnostic run

if your running stock ecu they can check what the prob is if they have the software