service engine light
sassygal5
07-10-2004, 07:28 AM
I have a 97 Grand Am. I posted a few days ago that my service engine came on & they replaced all the injectors & it still comes on, the idle is rough and I have trouble staring it ( not when it is cold or if I leaves it for 10 or 15 min.).
My mechanic now thinks it might be a crack in the manifold, he said he checked the wires & the coils (they are the originals). Does anyone out now if that could be the problem? Yesterday when the light came on it gave a code that ther was a misfire in 1,3,&5 cylinders. I am so aggrevated at this point and my mechanic is relying solely on what that computer tells him. Can someone out there help?
My mechanic now thinks it might be a crack in the manifold, he said he checked the wires & the coils (they are the originals). Does anyone out now if that could be the problem? Yesterday when the light came on it gave a code that ther was a misfire in 1,3,&5 cylinders. I am so aggrevated at this point and my mechanic is relying solely on what that computer tells him. Can someone out there help?
Slade901
07-10-2004, 08:07 AM
If you have not replaced the spark plugs/wires for a long time then it might time to replace it. The spark plug wires usually rubs on the engine block and grounds the spark plug wire and you will have spark problem. Simple solution would be to make sure that spark plug wires are separated away from each other and not touching the engine block. Check for corrosion on te spark plug wire tips and coat them good with a di-electric grease.
The Crankshaft Position Sensor (CKPS) supplies timing reference to the ICM (Ignition Control Module). If the CKPS is not working right or its wire grounding (rubbing) on the engine block then it will have problem supplying accurate timing signal and you will have spark problem.
Check your CTS (Coolant Temperature Sensor). If the CTS is bad, either it gives out a too cold signal or too hot signal to the computer.
If it is stuck in too hot, it signals the computer and in turn it will immediately close the fuel injectors and not stay long enough.
If it is stuck in too cold, it signals the computer and in turn it will immediately open the fuel injectors for a long time and probably flood the engine.
During initial startup (cold engine), the Normal CTS sends a cold signal to the computer to open the fuel injectors longer and then gradually returns the fuel injectors to normal operation as the temperature rises.
It could be your Fuel Pressure Regulator failing. The Fuel Pressure Regulator has a diaphragm inside and if that diaphragm ruptures, excess fuel is sucked into the Fuel Pressure Regulator vacuum hose and into the intake. Check the Fuel Pressure Regulator vacuum hose for any sign of fuel inside the vacuum hose (do it after running the engine for a while).
The Crankshaft Position Sensor (CKPS) supplies timing reference to the ICM (Ignition Control Module). If the CKPS is not working right or its wire grounding (rubbing) on the engine block then it will have problem supplying accurate timing signal and you will have spark problem.
Check your CTS (Coolant Temperature Sensor). If the CTS is bad, either it gives out a too cold signal or too hot signal to the computer.
If it is stuck in too hot, it signals the computer and in turn it will immediately close the fuel injectors and not stay long enough.
If it is stuck in too cold, it signals the computer and in turn it will immediately open the fuel injectors for a long time and probably flood the engine.
During initial startup (cold engine), the Normal CTS sends a cold signal to the computer to open the fuel injectors longer and then gradually returns the fuel injectors to normal operation as the temperature rises.
It could be your Fuel Pressure Regulator failing. The Fuel Pressure Regulator has a diaphragm inside and if that diaphragm ruptures, excess fuel is sucked into the Fuel Pressure Regulator vacuum hose and into the intake. Check the Fuel Pressure Regulator vacuum hose for any sign of fuel inside the vacuum hose (do it after running the engine for a while).
whpbooks
07-10-2004, 10:00 AM
[QUOTE=sassygal5]I have a 97 Grand Am. I posted a few days ago that my service engine came on & they replaced all the injectors & it still comes on, the idle is rough and I have trouble staring it ( not when it is cold or if I leaves it for 10 or 15 min.).
Hello,
this is my first post, so I hope this is right.
I have the same problem every year or so with my Grand Am, also a 1997. I just finished fixing the code for misfire on #2.
Replaced plugs, no better, finally replace one of the coils. That was it.
In the past I have had to replace the Ignition Modual - that fixed it a couple years ago.
I would suggest: replace plugs and the plug boot connectors.
If that does not do it: take Ignition module in and have it check at the auto store. If that is OK, you may want to but 1 coil and replace one of them. If problem continues, move the new coil to the other side and see if that works.
Good Luck
Hello,
this is my first post, so I hope this is right.
I have the same problem every year or so with my Grand Am, also a 1997. I just finished fixing the code for misfire on #2.
Replaced plugs, no better, finally replace one of the coils. That was it.
In the past I have had to replace the Ignition Modual - that fixed it a couple years ago.
I would suggest: replace plugs and the plug boot connectors.
If that does not do it: take Ignition module in and have it check at the auto store. If that is OK, you may want to but 1 coil and replace one of them. If problem continues, move the new coil to the other side and see if that works.
Good Luck
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