3.8 Bad Idle / TPS

[92_Regal]

1) Engine gives 21 and 22 codes (TPS voltage HI and LOW)

2) When it's left to idle, it eventually will start surging up and down

3) TPS was replaced

4) Took it into dealership to re-learn idle, and tech said after ECM codes were cleared, they would set again (hard-code)

5) Occasionally, when I try to start it, it runs to rich(?), because it doesn't run on all cylinders, surging exteremly bad.

 

I have no clue where to start any ideas?

 

1992 Buick Regal Custom 3.8 V6

[Robby1870]

that sounds like it could be your crank position sensor going out. It wont send a code and will cause the motor to not run all cylinders and seem like its running rich. The exhaust will smell like gas. The crank sensor sends a signal to your ECM telling it the crank position, how odd, plus rpms. If the ECM does not get this signal or the signal is intermittent, the ECM will not know when to fire the coils to fire the plugs. Therefore, some cylinders miss and the gas that is not combusted will go out the exhaust and thats the smell you are getting. Hope this helps

 

Robby

[rglguy]

first, check your IAC motor. if its not that move on to the coil pack, check for bad towers, if coil pack tests good, go look for burns on the ign, modual under the coil pack............... if the crank sensor is going, you will havea no start problem quite frequently........ if none of the above, take out your cam sensoer, and while turning crank, feel for a magnet on the cam gear..... if non of them, go to your MAF and MAP..............

 

put with no fuel , sounds to me like ignition modual under coil pack