Engine Miss with instrument problems??
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2nd Gear
Joined: Aug 2010
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Engine Miss with instrument problems??
I have a stock 90 model C4; Yesterday I was driving it when i noticed that it had a slight miss, the miss got to be more noticeable and then the digital speedo just went crazy showing all of the readings possible, the heater/ac turned itself on and went to auto, and the radio would turn on but you couldnt change the station....idk if they are related but it seems as though they are...I am a recent convert from mustangs to corvettes so I'm a bit lost so far, i have thought that it may be a ground, short, possibly the alt overcharging.. but i dont have the slightest clue where to start so.. i thought that somebody else may have had this issue before I started throwing money at my car... Thanks again
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The most basic thing would be to open the hood at night or in a darkened garage, remove the hood lamp fuse, start the engine, then watch for any sparks, arcing, or electrical creepycrawlies along the ignition and coil wires.
They are to be inspected every 30,000 miles and replaced at 60,000 miles, according to the FSM. These HE ignition cars (and the electronic components that rely on it) are very sensitive to bad wires.
If you don't see any sparks or arcing, I'd next pull the ECM codes and see if it's captured any errors. Here's how.
http://www.corvettebuyers.com/c4vettes/ecm.htm
They are to be inspected every 30,000 miles and replaced at 60,000 miles, according to the FSM. These HE ignition cars (and the electronic components that rely on it) are very sensitive to bad wires.
If you don't see any sparks or arcing, I'd next pull the ECM codes and see if it's captured any errors. Here's how.
http://www.corvettebuyers.com/c4vettes/ecm.htm
Last edited by onedef92; Aug 25, 2010 at 07:16 AM.
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Team Owner
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From: Fort Knox, KY
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creates a lot of electromagnetic interference (or EMI, also called radio frequency interference or RFI).
Corvette engineers first tackled the problem by adding a radio frequency interference static shield over the distributor in 1976.
Instructor
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Yuppers. Could be. Like I said, GM's H.E.I. (high energy ignition) system
creates a lot of electromagnetic interference (or EMI, also called radio frequency interference or RFI).
Corvette engineers first tackled the problem by adding a radio frequency interference static shield over the distributor in 1976.
creates a lot of electromagnetic interference (or EMI, also called radio frequency interference or RFI).
Corvette engineers first tackled the problem by adding a radio frequency interference static shield over the distributor in 1976.
Instructor
Joined: Aug 2010
Posts: 129
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I don't think the coil has ever been changed out. It is something to look at this weekend. Since we can't get codes, we have to go "old school" and start from the battery and go from there. Checking grounds and hot as we go. Tedious work. Thanks for the info.
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I have a stock 90 model C4; Yesterday I was driving it when i noticed that it had a slight miss, the miss got to be more noticeable and then the digital speedo just went crazy showing all of the readings possible, the heater/ac turned itself on and went to auto, and the radio would turn on but you couldnt change the station....idk if they are related but it seems as though they are...I am a recent convert from mustangs to corvettes so I'm a bit lost so far, i have thought that it may be a ground, short, possibly the alt overcharging.. but i dont have the slightest clue where to start so.. i thought that somebody else may have had this issue before I started throwing money at my car... Thanks again
Le Mans Master
Joined: Feb 2000
Posts: 9,715
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From: Kempner Texas
The most basic thing would be to open the hood at night or in a darkened garage, remove the hood lamp fuse, start the engine, then watch for any sparks, arcing, or electrical creepycrawlies along the ignition and coil wires.
They are to be inspected every 30,000 miles and replaced at 60,000 miles, according to the FSM. These HE ignition cars (and the electronic components that rely on it) are very sensitive to bad wires.
If you don't see any sparks or arcing, I'd next pull the ECM codes and see if it's captured any errors. Here's how.
http://www.corvettebuyers.com/c4vettes/ecm.htm
They are to be inspected every 30,000 miles and replaced at 60,000 miles, according to the FSM. These HE ignition cars (and the electronic components that rely on it) are very sensitive to bad wires.
If you don't see any sparks or arcing, I'd next pull the ECM codes and see if it's captured any errors. Here's how.
http://www.corvettebuyers.com/c4vettes/ecm.htm
One member posted he just found his arcing problem of the OPTI housing actually allowing spark to ARC THROUGH THE OPTI COVER onto the engine side of the WATER PUMP!!
Jake
