94 Lumina Ecu Problem?

[MARKA920]

I have a 94 lumina with a 3.1... picked it up for 400 bucks.... Engine has erratic idle throughout rpm range, sometimes runs strong, sometimes runs weak. If left to idle for five minutes, service light comes on. If I turn the key and drive it for four hours, the service light never comes on. The car has died and will turn over but no fire for 10+ minutes--- come back to it, starts right up. The sevice code is for rich mixture.

[Jonn]

Originally Posted by MARKA920

I have a 94 lumina with a 3.1... picked it up for 400 bucks.... Engine has erratic idle throughout rpm range, sometimes runs strong, sometimes runs weak. If left to idle for five minutes, service light comes on. If I turn the key and drive it for four hours, the service light never comes on. The car has died and will turn over but no fire for 10+ minutes--- come back to it, starts right up. The sevice code is for rich mixture.

I am no lumina guru, but if its been neglected, id buy if i could, a new O2 sensor, new TPS, new MAP sensor, new coolant sensor, new manifold air temp sensor if it has one. These parts are pretty cheap, and you can rule out those being at fault then. And if you really want to add some more, replace the electronic Ign. modual, crankshaft sensor, the 3 coils, plug wires, and plugs. Everyone will tell you ways to diagnose, and they are right, but if you have the money, like the car, and it is high mileage, these parts are on their way out anyway.