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I have been trying to diagnose this problem for some time now and have had no luck.
The car is a 97 Grand AM SE with the 3100 v6. When idling it stumbles a little but nothing too irregular. Seems to rev up fine in park. The problem occurs when in drive. The car idles at around 700rpm. It accelerates fine from 700-1200rpm but then it acts just like I took my foot off the gas. Power drops off drastically. It doesn't regain power until it hits approx 2000 rpm and then seems to accelerate fine again. Sometimes it seems to surge and the tach will jump in increments of about 250rpm.
I have used a scan tool to diagnose, but all parameters seem to be within spec.... with the exception of the injector pulse width. The service manual states that it should be between 1.5 and 3.0msec. Mine shows it at 4.5-5.0msec. This might explain why the car is VERY hard on fuel right now. It seems to be running rich. What controls the injector pulse width?
The problem appeared after I changed the front crankcase gasket (timing cover) due to a coolant leak. The leak was fixed and there is no water in the oil or anything like that. It may just be coincidence...... but I've got a sneaky suspicion that it is related to the repair.
Does anyone have any idea as to where I should concentrate my search.
I'd like to know where the ground (-) points are on the engine. The engine was jacked up in the car so its possible that something got pinched or a wire was broken. I have looked for any visual sign but everything I can see looks fine.
PLEASE HELP!
The car is a 97 Grand AM SE with the 3100 v6. When idling it stumbles a little but nothing too irregular. Seems to rev up fine in park. The problem occurs when in drive. The car idles at around 700rpm. It accelerates fine from 700-1200rpm but then it acts just like I took my foot off the gas. Power drops off drastically. It doesn't regain power until it hits approx 2000 rpm and then seems to accelerate fine again. Sometimes it seems to surge and the tach will jump in increments of about 250rpm.
I have used a scan tool to diagnose, but all parameters seem to be within spec.... with the exception of the injector pulse width. The service manual states that it should be between 1.5 and 3.0msec. Mine shows it at 4.5-5.0msec. This might explain why the car is VERY hard on fuel right now. It seems to be running rich. What controls the injector pulse width?
The problem appeared after I changed the front crankcase gasket (timing cover) due to a coolant leak. The leak was fixed and there is no water in the oil or anything like that. It may just be coincidence...... but I've got a sneaky suspicion that it is related to the repair.
Does anyone have any idea as to where I should concentrate my search.
I'd like to know where the ground (-) points are on the engine. The engine was jacked up in the car so its possible that something got pinched or a wire was broken. I have looked for any visual sign but everything I can see looks fine.
PLEASE HELP!
It was late when I posted.
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