I have a 1996 LT1 Camaro that runs fine when you first start it for about 5 minutes then after 5 minutes it starts missing and backfiring. I have replaced the opti, because last time it acted this way it was the opti. That did not fix the problem. I have an extra ICM and coil so I tried those and that did not fix the problem either. I have checked all the plug wires and they all seem to be in good condition and none are close too the headers. I also ran the car at night and seen no arching whatsoever. I have looked the car over for vaccum leaks and have not found any. I hooked a fuel pressure gauge to car and drove it with it sticking out the hood and it stayed between 32-40 psi while driving. The plugs in the car where just changed last week. I ohm both coils, ICM harness, and opti wire harness and they all ohm out perfect. I unhooked the passenger O2 sensor and drove it and it still did it (something I was reading about making it run in closed or open loop?). I have no idea what to do next. My son is in town from out of state and I wanted to spend some quality time with him at the dragstrip. Can anyone please help me out?

 

Also the only code it is throwing is P0300 random missfire.

 

what brand opti did you replace the old one with?


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Autozone Duralast

 

That might be your problem right there. I am having issues with my Formula as we speak. Same symptoms as you. I bought a Cardone one from Advance Auto. I suspect it is the cause of all my issues. I tried to go cheap(still $250 ) on the Opti, but China just doesn't know how to make good parts. If I can gather up $500 for a new Delco one, its going on. Keep us posted on your diagnoses and what fixes it.. I'll do the same.

 

I was watching a pretty educational video on the ignition system on these cars [autostream]http://autostream.com/camaroz28/?page_type=firebirdplayerthumbnail&framepage=200&t ransactionid=1351222618-653439239&posted_by=marshall51875_www.camaroz28.co m&youtube_video_id=lFCjaz6zHfc[/autostream] it said to mist the plug wires and boots with a water bottle. So I did and sure enough the opti area, a few boots, and a few wires where arching all over the place. Which is kinda crazy cause the wires are not even a month or so old. Maybe I need to get some new wires and invest in some header wrap. <<<< Is going to be the plan for tomorrow. I will let you know how it turns out.

 

It was the plug wires. None of the wires where close to the headers (well they where as far away as you can get them on these cars). At night looking at the plugs and wires I could see no arcing UNLESS I used a spray botlle with water and misted the wires and plug area. Then the arcing was very visible. I guess thats what happens with headers and cheap wires. Going to invest in some header wrap. Also to get a good view I had to mist from under the car at dark with it jacked up in the front and back and from the top. Use patience and take your time because one bad arc any where will cause all kinds of missing on these cars it seems.

 

Wrap the wires, not the headers. Header wrap causes excessive oxidation of the headers, increased thermal stress cracking, and can present a fire hazard with oil leaks. Taylor makes some braided fiberglass sleeves for the wires that work great.

 

Thank Injuneer sounds good I will do that. Is this what I should go with? Taylor Cable Products - Product Line Question though? Would I have to buy the "Made to Fit" plug wires to get this stuff on the plug wire or?

 

It seems there is a trend with the LT1s!!!!!
I have a 97 Z28 with the hooker headers, high flow cats, flowmaster cat back, MSD 6AL and Brand New MSD opti with nw MSD plug wires and new APP plugs. ( had the powerdyner 8lb on it before it started acting up with the other plug wires on it)

just pulled it out of the garage with all new ignition: wires, plugs, dist.
ran great for about a mile then started bucking and skipping. any ideas?

really looking for some guidance. (this is the first chevy ive owned in oiver 15 years)

 

The Taylor "firesleeves" that I bought many years ago were a silver cloth - no silicone. They were about 8" long and large enough diameter that you could thread the boot through it. I tied them in place (at the end, away from the header) with nylon ties to keep them from moving. They were protecting a set of Taylor 409 (10.4mm) wires, mounted over the valve covers through a set of JBA shorty headers. Never had a burned wire.

Currently running MSD 8.5's, under a set of AS&M mid-lengths, and have no protection on them and have never had a problem. But because I run 8 LS1 coils mounted behind the lower radiator support, the routing it nowhere near stock.

http://www.injuneer.com/images/photos/Engine/CoilsR.jpg

 

Nice setup Injuneer do you mind me asking what a set up like that cost. I'ld love to get rid of the opti off this thing? 1997 Z28 AB Double check those wires misting them at night and make sure they are not arcing no where (from what I have learned it does not take much to ruin them). Also watch that video I posted on post #6 and get a multimeter and do the multimeter test it shows on there. That multimeter test will test your opti, ignition control module, harnesses, and coil. Cant remember if coil is on there but for coil it should ohm 8300 from each prong to where the coil wire plugs in at. Test each prong and note that higher performance coils will ohm a bit lower. I think mine ohmed at 7900. Some people also do not realize on there cars there are 2 water temperature sensors. One runs your gauge and ones goes to the computer. If the one going to the computer is faulty it will cause your car to miss beleive it or not. Also the Map and throttle position sensor can cause it to miss as well. The knock sensor being bad or reading an exhuast leak or rocker arm tick etc.. can cause your car to run like crap as well as a bad or dirty MAF. MAFs can easily be cleaned with MAF cleaner. Low fuel pressure can cause a miss and this can be checked by hooking a fuel pressure guage to the shrader valve on the back of the intake and sticking the fuel gauge out the hood and watching it while driving. Mine stays between 32-40psi while driving. A bad injector can cause a miss and these can be checked with one of those noid lights. Vacuum leaks can also cause a miss. This website here will tell you everything you need to know and has detailed instructions on how to check sensors etc.. on these cars. 4th Gen LT1 F-Body Tech Aids I have had my car a little over a year and have already had 3 miss scenarios. One was cause by the opti due to who ever owned the car before me put the water pump shaft seal in wrong (there is a trick to putting tose things in) and it was leaking oil into the opti and destroyed it. The other 2 where cuased by the plug wires getting destroyed due to header heat. My second set of plug wires (cheap ones) did not last 2 months. I hope this helps if you have anymore questions I can try to answer them.

 

^^^Good info here!^^^ Im having the same problem with my TA and im definetly gonna use some of these methods trying to track down misfires.

 

good info
.......posting so i can find this later, lol