rb20 running like s***

[fast_s13]

alright my car ran good the first two weeks it was running then it started misfiring or some thing around 4500rpm.. if you ease in to it it runs fine but if you floor it it will misfire any ideas

[ibzbro]

mine did that samething i put new plugs in it, because i was running the ones that came in the eninge from japan. give that a shot, it is a cheap way to find out if that is a problem.

[Yellow4g63]

Check for boost leaks too. Intercooler piping might be lose and about to pop off.

[fast_s13]

done put new ngk's in it cant find any leaks anywhere

[ibzbro]

so dose it run any better?

[fast_s13]

nope

[ibzbro]

are you sure that your coil packs are good along with your ignitor?

[Yellow4g63]

it prob a bad coil pack. Just take the cover off and while the car is running unplug one at a time till you hear that it dosen't change it's idle.

[fast_s13]

the car idle's fine it only does it above 4500rpm at full throttle

[leroy0053]

do what Yellow4g63 says too. that is a common check. it may idle fine. but when u unplug a coil pack your idle will dip down. then u plug it in. then u pull a plug and the idle doesnt change, there is the bad one. if this doesnt work then u need to check again for vaccum leaks.

http://www.midnightillusion.comhttp://w ... senyou.com

[Projex240]

4500 and above--what about the plug gap? was it ever running alright--or was it like this from the beginning.

-josh