I posted a while ago asking about difference in MAF Sensor Brands. I finally got my Delphi MAF and it really tightened up WOT shifts. But a very common problem with these cars is an uphill surge due to the torque converter locking and unlocking. GM issued a TSB on this way back in 2003. Here it is.
The 4T40E/4T45E/4T65E automatic transmission may experience a slip surge condition in second, third and or fourth gears while under load, such as driving up a long hill or mountain. The conditions either separate or working in combination seem to cause the 'Engine Load %' to drop to a value which the PCM commands a lower line pressure (increase in PCS amperage).
'Normal' degradation of MAF over time aggravated by induction of foreign material (fine dust, oil from non-OEM air induction systems; secondly, build up of carbon deposits in combustion chamber/intake valves over time; thirdly, outside ambient temperatures above 95 degrees F(35 degrees C) seem to aggravate the condition. The MAF should be swapped from a known good unit or replaced and the vehicle evaluated.
I replaced my MAF sensor and it was good for about a week then came back. Im tired of exchanging parts over and over again. I know Delphi MAF's are really good. I have also replaced the 1-2 Shift Solenoid, 3-4 Shift Solenoid, PCS, and TCC Solenoid. Absolutely no change at all in the surge. I am almost positive its not mechanical, because this car started doing this when it was pretty much new. It has 245,000 miles now and still does it. A lot of Grand AM/Grand Prix had this problem, as well as the 97-03 Malibus. Everyone else that posted this problem for help said the MAF sensor fixed the problem
My fuel pressure is good too. Its got to be a sensor issue somewhere. There are no vacuum leaks. If I press the brake pedal, it stops doing it (disengage TCC). Has new plugs and wires, TPS, and CTS. It still drives fine. Its just really annoying and its got to be accelerating TCC wear by locking and unlocking constantly. I probably scared everyone away with this really long post lol. Sorry! And thanks in advance!
The 4T40E/4T45E/4T65E automatic transmission may experience a slip surge condition in second, third and or fourth gears while under load, such as driving up a long hill or mountain. The conditions either separate or working in combination seem to cause the 'Engine Load %' to drop to a value which the PCM commands a lower line pressure (increase in PCS amperage).
'Normal' degradation of MAF over time aggravated by induction of foreign material (fine dust, oil from non-OEM air induction systems; secondly, build up of carbon deposits in combustion chamber/intake valves over time; thirdly, outside ambient temperatures above 95 degrees F(35 degrees C) seem to aggravate the condition. The MAF should be swapped from a known good unit or replaced and the vehicle evaluated.
I replaced my MAF sensor and it was good for about a week then came back. Im tired of exchanging parts over and over again. I know Delphi MAF's are really good. I have also replaced the 1-2 Shift Solenoid, 3-4 Shift Solenoid, PCS, and TCC Solenoid. Absolutely no change at all in the surge. I am almost positive its not mechanical, because this car started doing this when it was pretty much new. It has 245,000 miles now and still does it. A lot of Grand AM/Grand Prix had this problem, as well as the 97-03 Malibus. Everyone else that posted this problem for help said the MAF sensor fixed the problem
