Electrical problem.....Help appreciated
 

Hello.....I have an '00, 6-spd that has exhibited the following problem....repeatedly!! The first occurance was while moving at 40mph. The motor started to slow down, the message center indicated "reduced power", the check engine light came on and the motor seemed to be running on 4 cyl at best. I parked the car and after waiting for a wrecker that did not appear, I tried to startthe car and to my surprise, it ran fine ( check engine remained on for about 10 miles).I had the car checked by a cert. mechanic....codes indicated a lot of misses on one cyl; a lessor number on another cyl.; but, not much else. The mechanic put it on a Modus unit and could not find anything else.We swapped the injectors from one side to the other and I started driving the car again. The problem reappeared ( the last few times, in the garage imediately after starting the car ) a few more times and each time I shut it off and let it sit for sometimes a couple of hours and it is usually "clean" when I restart it---but not always. The time span between occurrances varies from 20 days to as much as 3 months and I do not drive the car for up to a week at a time. Out of frustration, I changed out the CPU and Throttle Position Sensor.....thought it was o.k. until 4 months later and it is back again....same exact failure mode ( inmotion at about 50mph ). The last occurrance was two days ago and when I got it to the mechanic again, he could not find anything that seemed to be malfunctioning. This has obviously gone on for an extended period of time. When it is clean, it runs fine, 100% and there is no "tell-tale" evidence of the problem because after about 10 miles of driving, the check engine light goes out until the next event. Obviously, reliability is the issue and other than this problem, the car (46,000mi) runs fine and performs " as expected". Throught the painful process of elimination, I feel that I have one, or more, sensor that has gone "erratric"; but, I just haven't seen one that comes and goes like this problem.Has anyone else experienced a similar problem.....any good suggestions would be appreciated.

RE: Electrical problem.....Help appreciated
 

Had a camaro once that would exhibit similar symptoms, had a bad Ignition Coil. Would die when it got hot and crank fine when it cooled. Something to check. Good Luck

RE: Electrical problem.....Help appreciated
 

The same thing will happen if the wiring harness to the fuel injectors goes out, and they do fail (I had one on the 'vette fail at about 20 months). There is one harness on each side (for each set of four cylinders). If the cylinders that were giving problems were both on the same side of the engine, I would suspect the wiring harness on that side: its connectors to the main fuel injector system, etc. If the cylinders that gave problems were on opposite banks, I'd suspect the connector or the fuel injector wiring itself where both harnesses connect to the system. By the way, these things are expensive and not available indidivually from the dealer -- best plan if you suspect the harness itself is bad (mine was) and not the connectors is to find a replacement from awrecked vette or Camaro at a surplus yard.

Earlier model 'vettes had some problems with battery leakage (the battery is just above the ECM - engine control computer) where acid would eat down into the ECM and corrode the terminals on the connector to it. If all else fails you could remove it again and carefully inspect the area around it and the condition of the conectors.

Final note: if anyone has done modifications to the car;sunderhood wiringand used crimp-on connectors for any wiring modifications/patches to: the throttle-body wires (on wither side, those controlling it or those sensing it), the fuel injectors, the ignition system, or any of the various fuel-air and other sensors under the hood, have the crimp-on connectors removed and the wires soldered and insulated instead. Crimp-on connectors often have erratic singal transmission -- millisecond moments when they move or expand with heat and don't transmit the signals well, and the ECM interprets this as problems, and this will cause the problems your describe.

RE: Electrical problem.....Help appreciated
 

Hmmmm... thanks Lee didn't know that.