Car wont run right below 3K rpm????

[newdude1]

So I'm completely stumped on this problem. My car doesn't want to run right below 3k. Its almost like it is missing and hesitating when trying to hold a steady rev. But if you give it 3/4 to WOT it revs perfectly and smoothly above 3K. I have searched but haven't found anything like it.

I have done a leak test, not leaks at all. At least not in the piping. Where else could you have a leak from?

I also replaced and gaped all my spark plugs.

I replaced my fuel filter.

I set the timing perfectly.

My set up is z32 maf with JWT tune and 740cc injectors. Im ordering a wideband this weekend when I get paid but I want to know what else could cause this? Just throw out some ideas cuz now I am clueless on what to look for.

[Erjay1]

Interesting as I seem to be experiencing the same problem.I have a late model s14 engine with PowerFC. After 2500 rpm I can rev. Does your check engine light flash in conjunction with the engine misfiring or whatever it's doing?

[newdude1]

I also have the late model s14sr. And no it does not blink.

[Emperor_Tha]

Running rich = possibly knock sensorlean= hard wire the fuel pump

fix my problem.

[newdude1]

Well its not smoking at all so I dont think its running rich. Im not sure about lean tho.

[newdude1]

Any ideas anyone?

[mRodiek]

MAF

[newdude1]

Its not that. I can rev past 3 perfectly fine. And I replaced the maf with a perfectly working one. So Im 100% sure its not that.

[rprej251]

newdude did you ever solve your problem? i'm getting the same thing out of mine.

[240life]

newdude did you ever solve your problem? i'm getting the same thing out of mine.

Check your turbo to manifold gasket for leaks, this can cause poor idle and erratic afr readings

[rprej251]

alright thanks

[compactfean]

Does your car idle okay? If it doesn't than this could be a symptom of the iacv.

[rprej251]

It idles as close to perfect as it can. its just right when i go to hit the gas fast it wants to die. and when i,m easy on the gas it will revv normal.

[compactfean]

Have you checked tps? Make sure throttle is all the way closed, start the car and volt test the middle wire.( poke tip into wire connection from back through rubber) and use other tip at any good ground. Adjust tps while running closed throttle should be at. 45 volts.

[rprej251]

i check that and i have about .4 when closed to about 4 at full throttle.well now i got a new problem. i changed out ecu's now it revvs fine just running rough and very lean. i'm pretty confused