89 GALANT VR4 WONT GO OVER 3500RPM

Was wondering dose anyone know why my engine will rev to only 3500rpm while being driven. It will rev out to 7000rmp while stationary no problems but while being driven it will cough and splutter and go bloody slow at 3500rpm. engine is a 4g63t

cheers Ivan

 

I don't know what this is, but when I had my 1ga DSM I had this problem and was inexperienced and had a shop rip me
off and tell me that the low compression was causing this. Then another shop did the same thing to me too. In the end, there
was one wire going to the intake that was loose. I don't remember what on earth it was.

 

could it have been the throttle position sensor?

 

[boosted_85]

Have you tried a differnt ecu and or maf? Sounds like your in limp mode

 

Not sure what it was, the wire was sort of balled up in there. I guess in that case it had to have been some sort of exception. /ubbthreads/images/graemlins/frown.gif

Still, the theory may be the same.

 

[dmj]

Have you tried a boost leak test?

 

[Nabeel]

I had issue like this. It was bad ECU. Find a logger. Your car seems very rich. Bad temp. sensor or boost leak causes such problem also.

 

[conquesttsi]

Have you checked voltages at the injectors, resistor pack, ecu ports for the injectors, and fuel pump?

I had almost the same problem with my conquest and it turned out the fuel pump was not getting enough voltage.

It would hit 3500 and buck cause of bad fuel cut, however, the car would drive perfect below that amount of revs.

I too was able to rev higher when there was no load on the engine.