I have a 1991 Corolla DX with the 4A-FE engine. Recently I have two electrical problems that appear to be related, because they both started happening at the same time. The alternator will - on an intermittent basis - overcharge the battery. I have replaced the alternator (and integrated voltage regulator) and the battery. I have also checked the ground cable and the positive cable from the alternator. But I still have an intermittent overcharge condition. The second problem appears to be with the ignition or fuel system. The car idles rough, hesitats and surges at lower RPMs. I have replaced the plugs, wires, distributor, and oxygen sensor. But the car still has problems. Can a single, faulty component be causing both problems?
Alternator Overcharges and Engine Hesitates
- Thread starter IamaToyotaman
- Start date
Hi Scott, When the brake and battery indicator light come on, I tetsted the alternator output with a multimeter. I also had the alternator tested at the local parts store (while in the car), and they verified that the alternaotor overcharges when the indicator lights come on. Also, the altornator is boiling my battery. Practical wisdom lead us to think that the voltage regulator/alternator was bad and / or the battery had a bad cell. So the parts were replaced, but I still have the same problem. As for the tune-up parts, the car started running poorly at the same time as the alternator pproblem, and it had been 30,000 miles since the last tune-up. So I did a tune-up and tested the oxygen sensor (it also tested bad). But I'm convinced that the two problems are related. What I'm looking for is a common control point (like the computer - although I don't know if the computer comntrols the alternator output). Any thoughts?