I thought I already posted this so if I did I apologize. I have an '85 that started running real rough a day or two ago (like it wasn't running on all cyls). Not getting any trouble codes but it backfires (or detonates at boost) under load. . .any suggestions? THanks
it sounds like the crank sensor. you also want to check that there is no play in your crank pulley/balancer if it's a continuing problem for ya. If the harmonic balancer hits the crank sensor it will continue to damage the sensor (it happened to me, had to change the key in the crank [$.49]). You can easily check by removing the serpentine belt and go back and forth with the crank pulley.
Good luck, MARIO
That's a good diagnosis... a couple other things to check if that doesn't pan out:
- Loose/leaking/split intake hoses.
- Ignition module
- Coil pack
- MAF (unplug it and see if it runs better... if so, I suspect that it's toast)
- head gasket (hope not)
FIXED IT!!! This is almost embarrassing, however, never overlook the obvious. I was looking under the hood for signs of trouble (again) and noticed two plug wires had come off the cradle that holds them off the turbo outlet and had melted against it, so they were shorting out!!! Thanks to my wife, she noticed it before me. . .