Topic: 82 engine issues
in Forum: C3 Engines
Okay all of the crossfire owners... gather round!
My 82 with 35k miles starts up fine and has the high idle (1200-1500) to begin the warm up cycle, but then after 30 seconds, the idle dies instantly to 500 and stumbles like it's loading up! I can bring the gas manually back up to 1200 for about a minute and it stays there by itself. It continues on its own until closed loop begins and idle goes to 650 where it runs fine and smooth. Any clue why it dies?
Also, the other day I drove to town but noticed a shutter so bad that I had to pull over. It wouldn't take power and the headlights opened and closed by themselves!? I just knew a vaccum hose came lose... pulled the air cleaner, checked all the hoses but found all to be ok. This took about 10 minutes, so I put the cleaner back on, started up and idled fine! I turned the highlights on and everything checked out. I drove it home to continue the hunt for my ghost but the car ran as good as it could. No stumble, no headlight blinking and plenty of power!
I got home and let the car cool down (30 minutes) and tried again! It started fine, high idle, died after 30 seconds, warmed up with gas pedal and drove off. After 5 miles the shutter started again, no power and headlights started to open and close by themselves! Stopped for 15 minutes, and it drove like a bat out of hell home again.
Any possible clue to my ghost? I have new O2 sensor, EGR, IAC's, plugs and wires, thermavac on air cleaner, MAP, and coolant sensor! It ran like new until I replaced the brake booster this summer! I can't imagine what that had to do with this!?


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You may also have an issue with one of the IAC(idle air control) motors. If it gets hung open too far, it acts just like a really bad vacuum leak, which could cause the headlight issues, and the rough running.
I'd find someplace to get it scanned for possible codes first, then go from there.
Joel Adams
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There is a filter and a check valve. The "check valve" is actually attached to the front of the booster and the big vacuum hose from the engine connects to the check valve. It looks like just a plastic elbow but is actually a valve. There is a "filter" in the line also but closer to the engine. Since the booster works on vacuum the check valve allows air to travel only one way, kind of like the check valve on the headlight system. Since the rough running may be vacuum related AND you recently replaced the booster, it wont hurt to check the valve to see if its working. Those with far more knowledge than I have here could say if that could be causing the problem.