missfire in detail
01-15-2007, 05:44 PM
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missfire in detail 99 trans am a4: LTs, ORY, !air,!egr. Sd tune.
At the time of my tune my maf was bad so the sd tuned it. All o2s are shut off. I got a miss about two weeks after the tune. Plugs and wires were changed at Lt install maybe 3k mi ago. The miss occurs after the car is warmed up and under light load. Once above 2800rpm it runs like a raped date. So today i checked all fuses, and the 20a eng sens was bad. Replaced it and checked the plugs on driver side. Plugs are fine, as i imagine the plugs on the pass side are. There is spark at all 8 coil packs and all 8 plugs. Car was tuned at Greenlight and yes all o2s are off.
At the time of my tune my maf was bad so the sd tuned it. All o2s are shut off. I got a miss about two weeks after the tune. Plugs and wires were changed at Lt install maybe 3k mi ago. The miss occurs after the car is warmed up and under light load. Once above 2800rpm it runs like a raped date. So today i checked all fuses, and the 20a eng sens was bad. Replaced it and checked the plugs on driver side. Plugs are fine, as i imagine the plugs on the pass side are. There is spark at all 8 coil packs and all 8 plugs. Car was tuned at Greenlight and yes all o2s are off.
01-15-2007, 06:48 PM
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im having the same problem with my car , when i try to give it gas my borla exhaust sounds like garbage and the car barely wants to go after 2800 to 3000 rpms did u find your problem yet.. if so plz tell me what it was and i have fire to all coils and my plugs was changed 1 week ago.. thanx
01-15-2007, 08:05 PM
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The Eng Sens fuse powers (+12V) the 4 O2 sensors and the MAF only. Since you are not using any of those, the fuse being blown had nothing to do with your problem, although it may be why the MAF appeared to be bad at the time of the tune. Since you are apparently running a OLSD tune, you should probably have your tuner recheck everything.
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01-15-2007, 08:24 PM
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cause i want to go back, everyone told me at the time i bought a new maf that if i want to dd i would prefer a maf tune. now after reading with a sd you can tune easier with a big cam i am up in the air
01-15-2007, 08:32 PM
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The way i look at SD tunes is that in 93 and before, GM used SD, and they havent used it since, so it must not be that great. I'll stick with my MAF tune. Just my .02
01-15-2007, 08:51 PM
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i agree and disagree except most manufactures can get away without. it helped me rationalize my purchase, also i thought to myself it prolly was bad thats what shorted the fuse out. any more help
01-17-2007, 05:23 AM
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Originally Posted by 98 Raptor TA
The way i look at SD tunes is that in 93 and before, GM used SD, and they havent used it since, so it must not be that great. I'll stick with my MAF tune. Just my .02
01-17-2007, 12:02 PM
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i like how the maf compensates for things. i would like to turn the front o2s back on but do you think they will be burned up since they have not been registering
01-17-2007, 12:14 PM
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Originally Posted by dpw41285
i like how the maf compensates for things. i would like to turn the front o2s back on but do you think they will be burned up since they have not been registering
01-17-2007, 12:16 PM
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Originally Posted by 98 Raptor TA
The way i look at SD tunes is that in 93 and before, GM used SD, and they havent used it since, so it must not be that great. I'll stick with my MAF tune. Just my .02
Even as late as 05 the I6's were in SD...I think for emissions purposes GM finally switched over to maf in 06 on their I6's.
01-17-2007, 12:20 PM
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what wont be worth their weight? i just put in a new maf, the cam i will be running will be 235/239 600.600 112lsa is that gonna make tuning with the maf hard?