Engine surges and is short on power...

[J30tman]

First off, I have a 1993 J30t with 123k on it. The car starts and idle's fine. It will reach redline fine. It just doesn't pull like it should or like it did when I got it a year ago. When accelerate from a stop the car surges as it reaches my desired speed. It is not violent just very anoying. I don't even notice the variable valve timing anymore. I have replaced the coolant temp sensor cause I thought it might be related to that. Do you guys have any sugestions?

[KUL FIR CHICK N]

Your problem sounds exactly like mine. I checked my codes and it has a knock sensor fault. You have to remove the intake to replace the knock sensors (2) and sensor harness. I'm hoping someone will give me a hint on how I might fool the computer into thinking the sensors are working properly. If the computer senses a knock sensor problem, it will retard the timing, which will severely reduce power.

When mine acts up, it also shifts hard under full throttle accelleration.

Ryan

[J30tman]

Well, It would be nice if I knew how to bypass the knock sensor. I would like to add that my check engine light is NOT on. I would think if the knock sensor was at fault it would light up the check engine light... correct?

[yodawill2000]

If the knock sensors throw an error I personally would like to know about it ...

[J30tman]

Are you saying that the knock sensor will not light up the check engine light?... I have no idea here, help me out.

Ok, for instance, lets say that the knock sensor is at fault. Can I just unplug it for now and go on? Do I need to reset the computer before I unhook it and drive it? Will the car still run the same if I unhook it and not reset the computer? I am at a loss here and can't take it to the dealer for repairs.

[KUL FIR CHICK N]

Its a code 34 and it won't turn on the check engine light. I found it after I bought a consult cable and checked the codes. Re-setting the codes doesn't help because it immediately sets another fault. You can't remove the sensors because it will set the same code.

When the ecu senses a knock sensor fault, it will retard the timing to be safe. Mine looks like it is retarded somewhere between 6 and 15 degrees!

[J30tman]

Ok, so unpluging the sensor and resetting the computer will do no good.? That sucks. For future references... how do I reset the computer anyway?

[yodawill2000]

zerothread/183775