Misfire at over 200 degrees???

[topless94style2]

Sweet let us know how it turns out

[tornado_735]

Code 34- Which in my car's case means, MAP Sensor.

I called it!! And definitely let us know what happens.

[Starflare5]

I decided to reproduce the issue to see if any other codes came up just in case before I go to the junk yard. 2 more appeared, Code 33 which confirms the MAP sensor, and a Code 35 Which is the Idle Air Control Valve.

[RobertISaar]

DTC 35 sets when the idle speed is ~150RPM above desired for about 30 seconds or more.

[Starflare5]

Well,

I replaced all 3, reset the codes, yet, was able to reproduce the issue again. The end result was still just a code 22 (Throttle Position Sensor). I have been advised though that before I try to replace this with a new or another one, that I should get a few other things done to the car first, like, adjust the idle slightly higher for the time being, and then, change the injectors, for which, I've known they were bad and clogged for awhile just by the way the engine had been running for quite sometime. Then, reset the codes and fire it up again and attempt to reproduce the issue again. So, now, that's next.

Thanks guys,
Starflare5.

[RobertISaar]

you CANNOT adjust the idle via the idle adjustment screw on the TB and have good results. reason being you'll cause two things to happen: the base TPS voltage for 0% will be changed causing some drivability issues until it's relearned and the IAC will fight your changes by opening/closing more to maintain the idle that is commanded by the ECM, leaving you with the same idle speed and bad drivability.

you should have roughly .5 volts from the TPS with the throttle fully closed. anything too far beyond that in either direction will cause issues.

[Jerry O]

I just picked up an STG OBD1 reader I live in Milford going to the oldsmobile bday in Lansing Saturday let me know if I can help

[19Cutlass94]

I have spare TPS and IAC sensors Ill let go for dirt cheap.

[Starflare5]

Well, after replacing both the MAP and throttle position, the same error codes showed up again, but, also brought along a friend or 2. Codes 35 (idle speed) and 44 (intake vacuum leak). I think my vehicle might be a victim of the old GM 3.1 intake leak reported years ago. It doesn't seem to be leaking coolant... yet, but the vacuum leaks are present.

[topless94style2]

After re-reading this thread I started to think Intake leak, but when I had this happen, it was the opposite of your symptoms. Would barely idle when cold, and at running temps it ran fine. Worth a shot, spray a little ether or other start fluid around that area when the vehicle is on during the poor idle condition and see if anything changes. If the idle goes up, then its sucking in the fluid which means vac leak.

[Starflare5]

Unfortunately, the Buick took a turn for the worse. Turns out that it had broken part of the lifter assembly and became too expensive to fix. The car got sent away to a new junk yard here, however, I now have a Cutlass Supreme back. A 1994 Cutlass Supreme SL 4 Door that I only paid $1000 for on Craigslist. Pictures soon.