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silverbullet
12-19-2013, 08:14 PM
Car is a 94 m6 car. Has cai, headers, an ory. No other engine mods. Plugs looked good when I checked them two weeks ago when installing over valve cover msd wires. Had 2 spark plug wires burned from headers. I have a terrible spark knock under low rpm high load pulls. Can hear it and have only driven it to try to datalog it . Not very familiar with the pids that they use so I am getting very far. Verified that I have good fuel pressure at idle and under load when the problem is present. I could send someone who knows what they are looking at my log file I just don't want to keep driving it and burn a valve or something. any help would be greatly appreciated. Thanks in advance

silverbullet
12-19-2013, 08:17 PM
also car drove fine for almost a week and a half before starting this. I did swap out icms to a known good one because it seemed like a heat related problem at first and I had it laying around. It had no affect on it at all still ran the same. Also did unhook maf sensor to rule that out

nateleduc
12-22-2013, 08:21 PM
Hate to say it,but it kinda sounds like an opti issue. There is a guide to test out if it is the opti somewhere, I'd start with that

silverbullet
12-22-2013, 10:17 PM
I pulled up an old log file and everything is looking the same but my blms are low and amount of advance is significantly lower. Timing advance now is 8 degrees on last log and getting the full 15 degrees of knock retard. BLMs are down in the 90's and it runs worse and worse the longer you run it. Its sad because I just put this opti on 5 months ago and haven't even put 3000 miles on it. And the same opti I bought then went from a little over a hundred bucks to 399 from chandler

Mystery Bird
12-23-2013, 06:43 AM
Are you running premium gas? How many miles on the car?

silverbullet
12-23-2013, 05:43 PM
I am running 93 octane fuel in the car have been except one tank when I first bought it because that is what the seller said he ran. I never had spark knock even with that one tank of 87 in march. I though possibly bad fuel at first and was at about 1/4 tank so syphoned all the fuel I could get out and put 5 gallons of fresh 93 in. Car has 214k on it now and I am not sure if timing chain has been touched but car idles fine and is idling at 20 degrees advance and does fine in the upper rpm with no knock retard. I assumed from experience with other cars if base engine timing was off like timing chain jumped my timing at idle would be off because it would be trying to compensate. I have also checked for exhaust gasses in cooling system with one of those chemical testers and no problems. Used a vantage pro to monitor sensor outputs to pcm and nothing looks bad. plugs are ok rechecked them Saturday. 02 sensors are new denso's and everything is looking good there. Only thing I am left with in my opinion is opti is bad. Want to check that all out hopefully tomorrow afternoon since I will have a little spare time. I'll try to post my findings