I have a ptm 90mm throttle body that I bought brand new, it took my a while to get it installed cause my car was down. But now that it is installed the car throws the code for the throttle position sensor. I've changed the sensor out 3 times, and I get the same thing. The are also tries to die when I take off, once it tries to die I can push the peddle all the way down and it will die more. I have to let the peddle all the way out and let the car start to roll on its own then get back into the throttle. My tuner has tried everything he knows to fix it and now he thinks it could be the throttle body. Has anyone ever heard of this? I started to think maybe the throttle body is machined wrong where the sensor is and it is not getting enough vacuum to the sensor. Maybe I'm wrong and the sensor doesn't even need vacuum, but I can't think of anything else.

 

Your tuner needs to either disable that P0121 code or widen the parameters for it. You're seeing more airflow at a given RPM than you used to and the PCM thinks the throttle position sensor must be whacked.

P0121 code makes the car go into speed density mode too, I believe - my car ran like *** when it was throwing that code.

Rob (Bad30th)

 

Does that explain why it's falls on it's face? Or could that be something else?

 

Could be anything, but if the new TB was the only change that's my bet.

If your MAF table is off far enough, yes, your car will absolutely fall on its face.

If you're getting a P0121 it sounds like your MAF table is probably off pretty good, and the code parameters should be widened so you can get it tuned.

Did your tuner change the MAF table for the new MAF ?

Rob (Bad30th)