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Discussion Starter #1
Hi Guys,

I am new to this forum. I have been having problems with my 2003 50th Anniversary Addition Corvette (20,000 miles). Two years ago, after sitting for a year, I took it for a ride and it missed terribly. I assumed bad gas and drained it. Also pulled the injectors and sent them to be cleaned and changed the spark plugs. Still missed. Since then I have changed the spark plug wires and all eight coils. It still misses but there have been two occasions when I drove it and it run great. The scanner continues to show either; "Cylinder 5 misfire detected" or "Multiple cylinder miss fires detected". I have also run 44K through it. I am thinking perhaps the crankshaft or camshaft position sensors. It looks like they are no picnic. I welcome any help.

Thank you

Rich
 

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Welcome to the forum. I would try the old mist the plug wires with some water and run at night to check for spark leakage. Do not assume the new coils you put on car are good. Same goes for plug wires.

If you are thinking crank or cam sensor are acting up, one of those $70 pc based oscilloscopes sold on ebay, amazon, etc, would be the best way to check their signals.

Since car runs well sometimes and misses at others, checking the crank & cam signal with a scope while engine is running would either pinpoint one or both of them as a problem, or eliminate them as suspects.

If signal from either degrades when car starts acting up, you have your suspect. But don't forget that wiring, connectors, bad grounds, etc can cause what appears to be a bad sensor.
 

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Discussion Starter #3
Thank you I will start with the water misting. I have never used an oscilloscope but imagine it comes with instructions. This is frustrating. Thanks again for the quick response.
 

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Thanks for all of the support. Yes I did replace the spark plugs, wires and all 8 coils, cleaned injectors and changed gas. Will do compression test. This started when I drove it after sitting for more than a year will stale gas. I wonder if it is related to that.
 

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Discussion Starter #7
Still working on it

I ran my 2003 Corvette at night time while gently tugging on the wires but no arcs. I then misted the coils, plug wires and plugs while it was running. It did not miss any worse nor did it improve. I then poured in another can 44K. It smoothed out and I took it for 10 mile drive and it ran quite well, but it has done this before. I will need to run it more times but it has been raining here every single day. My driveway is a muddy mess so I need a day or two of dry weather. I appreciate everyone's help and will keep you posted.
On another subject, is anyone familiar with Honda GL1000 clutches?
 

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I think I fixed the miss. While beginning to perform a compression check I discovered a cracked spark plug. After replacing it the engine ran fine. I am now detailing the car in preparation to sell it. I have too many toys and time to down size. I want to thank everyone for their help.
 
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