'95 Grand Am 3100 seems to cut out and lose power pretty badly during cruising and during moderate acceleration, but when applying full throttle it seems to come out of it and pull strong. No check engine light. Also seems to have faint gasoline smell while it's acting up. Two of the three coil packs appear to have been replaced. I suspect the ign module, or possibly a bad coil. Anyone have any other possibilities?
Just had ignition module tested at parts store, tested out good. Car has 161k miles. Also, car's owner says she had to really tromp on it a couple of days ago to avoid an accident, and she thinks that's when this problem started.
I'm going through a similar type thing with my 94 pontiac transport also a 3.1. Mine burns antifreeze, loss of power, poor mileage and a bit of rough running (not too bad)... I found that the 3.1's commonly develop a leak of the intake manifold that can lead to injestion of coolant and these types of issues....
i have a call into a shop for an estimate right now.
So, my Q is whether you are using antifreeze up? Also google "intake manifold gasket 3.1" and see what comes up & whether it matches your prob's.
Sounds like you're running rich... if it's not above, I'd be thinking about the O2 sensor, and engine temp sender (the one to the ECM and not gauge)... maybe computers running you in a very rich mode.
BTW, just because the CEL: didn't come > '95 Grand Am 3100 seems to cut out and lose power pretty badly during
Disconnecting the EGR made all the symptoms disappear and it ran perfectly without it plugged in. It's the digital style EGR with the 3 pintles in it and thus not as easy to test as the old ones. I'm wondering if the EGR itself is bad or if it's getting faulty signal from the ECM. If the ECM is bad that would explain why there was no MIL, I've had that happen before. It had no MIL displayed until after I'd disconnected the EGR and even then it didn't come on until after about an hour of driving, which I thought was odd.
MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.