Yesterday morning, went out with the family to head out shopping. Air temp about 50 degrees. Started up the GP, drove 2 blocks and stopped at a store for a few minutes to pick something up before we headed to our final destination. Got back in the car, started it, and it nearly stalled. Gave it a little gas (TB needs cleaned, so this is normal), put it in reverse and gave it a little gas. The car started bucking and lurching as it went back. Tach kept bouncing up to 3-4000, but the motor noise sounded more like half that. Put the car in drive, gave it gas, same deal. With each push of the accelerator, no matter how hard, the motor would lurch and surge 4-5 times before returning to normal idle. I limped back home, we transferred to my wife's car, and went on our way.
Got home about 2 hours later. Plugged in my code scanner... nothing. Started the car, nothing. Ran fine. Let it run a bit till the temp came off the peg, still ran fine. Exhaust smelled rich, and it's been getting crappy mileage the last couple tanks. I just chalked it up to my driving. (I do like jackrabbit starts.)
My gut is telling me it's a bad sensor... ECT (engine coolant temp), IAT (intake air temp), MAP, or MAF. Had something similar happen to my last car, but can't remember which it was. Without it throwing codes, how can I diagnose this?
