Ka4e Engine Problems 240sx

[rocksteady_racer]

Here are the symptoms. When it's first started and not warmed it barely revs past 3000 rpm and runs incredibly rich. Then when it is warmed up, the idle is really low. It also won't rev past 5k-5.5k rpm at all. The compression on the engine is perfect. It passed emissions with flying colors last time. I replaced the fpr with an aeromotive one. I checked the pressure on the intake manifold and I checked the egr to make sure it was holding pressure - both came out good. However, the manifold pressure is bouncing slightly back in forth and my instructions for the gauge says that's caused by a rich condition. So which leads me back to it running rich but why? I think the BPT valve is leaking. I was thinking about swapping it but only if it will fix my problem since a new one is 70$. Thanks in advance for your help.

[monsta_civic]

check maf sensor, sounds like it might be dirty, then check iacv, fuel pressure regulator, easy simple fixes and if that doesn solve it spend the 70$

[Iron_Zenki]

yes check the MAF also the air temperature sensor clean the hell out of those suckers also:smash:
clean all around throttle body and inside
AND check your vacumm lines for no leaks

[T_wei]

could be a huge exhaust leak

[rocksteady_racer]

Would an exhaust leak also cause an build up of carbon inside the intake manifold? I figured that was just caused by the rich condition. But then I noticed one of the exhaust studs had snapped off the block so that maybe the problem...

[jspec240]

No an exhaust leak would not create build up in the intake mani.....

[rocksteady_racer]

What would cause an excessive carbon build up inside the intake manifold? Gasket Leak maybe? The vacuum pressure in the manifold was good. Or egr problem?