JHawk GT
09-03-2002, 02:48 PM
About a month ago my 02 GT started hesitating/jerking intermittently. The first time it happened I was going up a low grade incline. Since then, it has happened while going downhill and on flat roads. There doesn’t seem to be anything consistent about when it happens. Sometimes it happens five minutes after I’ve started it, sometimes when it’s been running for half an hour or longer. Outside temp doesn't matter either. I’ve never had any warning lights come on and engine temp has always been at 200. It usually happens at about 35-40mph and around 1600-1800rpms. When it hesitates, the tach has dropped as much as 300rpms, but only for the split second of hesitation, then it jumps back up. I’ve tried accelerating while it’s happening to see if it’ll go away. The only thing that does is increase the time between each hesitation. It always just goes away on its own. Sort of feels like my wheels are losing traction, but the roads have always been dry when it happened. My car only has about 1300 miles on it (first oil change at 500 miles), and it has happened maybe once or twice a week. This has got me stumped???? I’ve had the car for a couple of months and followed the manual precisely with the engine break-in and am pretty compulsive about correct maintenance, fuel type, fluids, etc.
I thought about PCM recalibration and checked it out at the GM vehicle calibration info site. This is what came up:
12218184 12218172 N/A N/A control module
12221354 12221348 N/A N/A new calibration to revise the fuel pump prime delay for new design fuel pump. calibration is also compatable with old design fuel pump.
12223754 12223483 N/A N/A calibration to improve obd 2 diagnostics
12224924 12224908 N/A N/A calibration change to enable mil illumination for dtc p0125
The air and fuel filters are fine, and I checked the plugs and plug wires—no problem there either. I’m going to take it in to the dealer but thought someone may have some ideas about what the problem might be. I have no idea what to have the tech look for unless I wait until it’s happening and take him for a drive. Any help would be appreciated—this is weird?????
I thought about PCM recalibration and checked it out at the GM vehicle calibration info site. This is what came up:
12218184 12218172 N/A N/A control module
12221354 12221348 N/A N/A new calibration to revise the fuel pump prime delay for new design fuel pump. calibration is also compatable with old design fuel pump.
12223754 12223483 N/A N/A calibration to improve obd 2 diagnostics
12224924 12224908 N/A N/A calibration change to enable mil illumination for dtc p0125
The air and fuel filters are fine, and I checked the plugs and plug wires—no problem there either. I’m going to take it in to the dealer but thought someone may have some ideas about what the problem might be. I have no idea what to have the tech look for unless I wait until it’s happening and take him for a drive. Any help would be appreciated—this is weird?????