SOS: Surging, hesitation and rpm fluctuation
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Joined: Jun 2002
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From: Benton Harbor, MI
SOS: Surging, hesitation and rpm fluctuation
My 89 Pontiac Firebird Formula has got me and my mechanic stumped. Fot the past year or so, the rpm's have been significantly fluctuating after the engine warms up. When I come to a complete stop with my foot on the brake the car continues to surge forward with the rpm's fluctuating and even shutting off at times. The SES light stays on constantly. At various speeds the car surges, hesitates and accelerates back to normal speed. I recently got a new gasket, Distr. Rotor, Cap. Distr, Spark Plugs, Gskts Bol, Cyl Heads, set timing and replaced #7 injector. Its still doing the same thing. Can someboby offer any suggestions. Don't want to give up on my baby!
Desperate in Michigan!!!!
Desperate in Michigan!!!!
Last edited by eddandrsn; Jun 10, 2002 at 08:35 PM.
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Ed,
Welcome Aboard!
Don't give up quite yet. WE haven't even started on the problem yet, and I'm betting we can get you enough information to steer your mechanic straight.
We really do need any error code information you can provide, however. If you haven't done it yet, it's so easy that even I can do it.
First, you'll need to acquire a GM OBD I ECM Diagnostic Trouble Code Retrieval Tool (commonly known as a paper clip to TGO members). You'll also need a notepad, pen, pencil, crayon, or other writing instrument. And you'll need the ignition key.
With the engine and ignition turned off, locate the ALDL connector under the dash, just to the right or left of the steering wheel in the driver's foot well area. There should be a small rectangular cover over the access hole in the lower dash trim.
Insert a tool as described above (paper clip) into the 'A' and 'B' terminals on the ALDL connector:
WITHOUT STARTING the engine, turn the ignition to the "RUN" position. Watch the Malfunction Indicator Lamp (MIL) - it will begin to flash. This is also commonly called the "Service Engine Soon" or "SES" lamp. The first code will flash three times, and will usually be a code '12'. This is encoded by one flash of the lamp, a brief pause, then two successive flashes of the lamp. Each code will repeat three times, so you should see a "Code 12" flash three times. Any other error codes will follow in numerical order, and each code should flash three times. After all codes have been displayed three times, the "Code 12" will again flash three times, then all other codes will follow as described earlier. This cycle will continue until the jumper is removed or the ignition is turned off.
After you have made a note of all error codes, turn off the ignition and remove the jumper immediately. If you forget to remove the jumper and attempt to start the engine with it in place, you could damage the ECM. For this reason you should remove it immediately.
Once you have a note of all error codes, check this file for the decoding:
GM Error Codes.pdf.
(You'll need Adobe Acrobat Reader to view/print the file.)
Welcome Aboard!
Don't give up quite yet. WE haven't even started on the problem yet, and I'm betting we can get you enough information to steer your mechanic straight.
We really do need any error code information you can provide, however. If you haven't done it yet, it's so easy that even I can do it.
First, you'll need to acquire a GM OBD I ECM Diagnostic Trouble Code Retrieval Tool (commonly known as a paper clip to TGO members). You'll also need a notepad, pen, pencil, crayon, or other writing instrument. And you'll need the ignition key.
With the engine and ignition turned off, locate the ALDL connector under the dash, just to the right or left of the steering wheel in the driver's foot well area. There should be a small rectangular cover over the access hole in the lower dash trim.
Insert a tool as described above (paper clip) into the 'A' and 'B' terminals on the ALDL connector:
WITHOUT STARTING the engine, turn the ignition to the "RUN" position. Watch the Malfunction Indicator Lamp (MIL) - it will begin to flash. This is also commonly called the "Service Engine Soon" or "SES" lamp. The first code will flash three times, and will usually be a code '12'. This is encoded by one flash of the lamp, a brief pause, then two successive flashes of the lamp. Each code will repeat three times, so you should see a "Code 12" flash three times. Any other error codes will follow in numerical order, and each code should flash three times. After all codes have been displayed three times, the "Code 12" will again flash three times, then all other codes will follow as described earlier. This cycle will continue until the jumper is removed or the ignition is turned off.
After you have made a note of all error codes, turn off the ignition and remove the jumper immediately. If you forget to remove the jumper and attempt to start the engine with it in place, you could damage the ECM. For this reason you should remove it immediately.
Once you have a note of all error codes, check this file for the decoding:
GM Error Codes.pdf.
(You'll need Adobe Acrobat Reader to view/print the file.)
Last edited by Vader; Jun 11, 2002 at 03:26 PM.
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