Problem With Misfiring Engine.. Timing Problem?

[brother_david]

Hi, i got a problem with my r33 gtst.

When i drive the car and it hasnt reached normal driving temp i can rev it any way i want, but when it has reached normal temp it starts to misfire badly around 5000 rpms, earlier i had the CAS turned a fairly bit anti-clockwise and the phenomena occured around 4000 rpms.

Im thinking of trying to turn it even more clockwise (is in the middle now) to see if it gets any better.

Does anyone know what might be causing this??

Cheers!

-David

[brother_david]

I was thinking...

Maybe its the sparkplugs anyway, cause i changed the ones i had to new ngk's some time ago.

Could it be that when the plugs get hotter and hotter they get softer and softer (the electrode anyway) so that the car starts misfiring easier, meaning that the gap increases easier?

Cheers!

-David

Edited April 16, 2007 by brother_david

[Mr. Oizo]

What heatrange plugs are you using?

[RB30-POWER]

Its easier to ignite a rich mixture then it is to ignite a leaner mixture, so it could be the coil packs with hairline cracks allowing the spark to find an easier path to earth.

Also you can't just turn the CAS or you cause your motor to detonate if you over advance the timing. Get a timing light and to it properly or expect to be rebuilding your motor soon.

[brother_david]

Thanks for your answers

Im using heatrange 7, NGK's .11 mm gapped to .08 . Im getting em out tomorrow and checking the state of them.

Yea i know turning the CAS to much will cause the engine to detonate, only done small and short test , fortunatly a friend of mine is picking up his timing light any day so then ill be able to see what the timing is set to, i'm currently running it centered and not revving to much.

I took the coil packs out, cheking the state, when the car was standing still in the garage (for a couple of months over winter) Didnt find any cracks then but since i didnt have this problem before they might have come after taking it out again. If i have the time ill take a look at them again tomorrow!

The thing is when it starts to misfire it sounds like its running on 5 cylinders or something, not the same problem last time i had spark plug issues but then i was running different plugs.

Thanks again!