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1995 Trans Am with edelbrock headers/hypertech programmed/aftermarket ram air. Going to try to make this as short as possible. I have had an ignition miss/running poor for about 2 years or so. I have changed all plugs, wires, optispark/rotor, coil, ignition module, MAF, and all other sensors numerous times all to have the miss come back after a quick test drive. Looking under the hood (at night)my wires will ground out and spark on anything they touch. (ie. painted body/firewall, brackets, each other, headers, anything) The car will run smooth as glass until it heats up. I have an EGR bypass, skip shift unplugged from the ecu and my secondary air removed. Those are the only codes that are showing. My question is "Why are the plugs wanting to ground out so much?". There seems to be too much resistance. All my grounds are good and I am running out of ideas. I was told it might be my ecu acting up but how would that cause a missfire? Also, how do you check your ecu? I need any advice and I am tired of dealerships, shops, all of the above telling me it is something not even related just to see if I will spend money. Posts: 4 | Registered: May 2003
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Welcome to the board! You diagnosed your own concern with those arcing spark plug wires.The wire insulation is broke down and they need to be replaced.Electricity will find the shorted path to ground.Replace the plug wires with some AC Delco or MDS wires.They are expensive,but cheap wires will give you the same trouble in less time.
-------------------- Current ride is: 2002 Brickyard 400 35th Anniversary LE convertible #22,SLP build# 0036,35th Anniversary Build #47 EMCC Member #234 www.emcamaro.org WCA Member #197582 MMCC Member #28 NEOCC Member #634 Posts: 5682 | From: Dearborn,Mi. | Registered: Feb 2002
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The wires will arc out no matter what. The wires are brand new. Like all the other things. It is so confusing. I can understand if they arc out in one or two places but they will arc out new, and in any place the wires will touch anything. Like I said they will arc out on the body, other wires, anywhere. I am trying to figure out why having a completely new ignition system has so much resistance. I have been using AC Delco 7mm, MSD 8mm, Mallory 8mm, and just about every plug except ac delcos because of my headers. i have a small plug clearance problem with the longer plugs.
quote:Originally posted by stock SVT: The wires will arc out no matter what. The wires are brand new. Like all the other things. It is so confusing. I can understand if they arc out in one or two places but they will arc out new, and in any place the wires will touch anything. Like I said they will arc out on the body, other wires, anywhere. I am trying to figure out why having a completely new ignition system has so much resistance. I have been using AC Delco 7mm, MSD 8mm, Mallory 8mm, and just about every plug except ac delcos because of my headers. i have a small plug clearance problem with the longer plugs.
Greg
I would try a set of stock AC Delco spark plugs.For some reason the spark is looking for the shortest path to ground even though you have new plug wires. New wires should not do that.
Posts: 5682 | From: Dearborn,Mi. | Registered: Feb 2002
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Sounds like your spark plugs have WAY too much resistance, so the spark is looking for any way it can to find a ground. Replace your plugs, then retest it. If it has been misfiring for 2 years, then plan on replacing your cats as well Posts: 1443 | From: Lake Oswego, Oregon | Registered: Dec 2001
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I have tried new plugs, new wires, etc.. and every time it will miss out again with in 10 mins of driving or so. I just cannot understand why there is so much resistance in my wires and plugs. Also, my car does not currently have any cats. I usually just park it and take it to the track. My daily driver is a mustang.
Posts: 4 | Registered: May 2003
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I'm a bit new to the intricacies of the LT1 but this type of problem can often be traced to a poor ground. Did this problem appear when the headers were added? Perhaps a ground strap is improperly attached. I would closely inspect all engine grounds, and if they check out I might add a good engine-to-chassis ground.
Posts: 4 | From: Lake Anna, VA | Registered: May 2003
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That is what I originally thought. So I checked all my grounds and noticed the ground for the battery to the block was off. Not sure if when we pulled the motor or when. So I re-attached the ground to the block at the motor mount bolt and checked the others. I pulled off the block to the firewall ground and cleaned it all up. Still have alot of spark.
Most recently it is acting all crazy now. I am thinking it might be a bad computer. I can drive the car and it misses at lower rpms and but it pulls smooth and strong in the higher gears. I am about to just give up and focus on my cobra. I need a way to test the computer. I do not have access to just swap a computer out and try it and I do not have the money to just throw it at a new one also.
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