Mystic97Z

le1 head/cammed car, madz28 tune, had an absolutely bad misfire, found out my #4 cylinder wasn't getting spark, replaced my opti, the miss is 50% better, but still is vibrating like hell below 2100 rpms,
i have a gm scanner but its not picking up any misfires, my computer was tuned by madz28, anyone else have this problem or have any suggestions?
been messing w/ this problems for way too long, about 3 weeks..
thanks for any help
-Jason

ny_z28man

If it was happening after the tune but didnt happen before id say send the Pcm back and have him reprogram it again. Something could have happened in the process. If it did it before I'd check the damper on the front of the engine, sometimes those weights in the back can fall off. Its got to be something rotating to cause that vibration. Also see if it does it in drive and in nuetral. Check your pulleys too. Thats about all I got with the info you gave. If something new comes up post it. See-ya man,
-Paul

Mystic97Z

no, its not the tune thats making it misfire, its the tune that wont let the misfire show up on the scanner, the car was running fine with the madz28 tune for about 3 months before this came up. my dad drove it tonight and said it feels like an ignition, so we're going to go through the same process AGAIN and make sure all my cylinders are getting spark.
thanks for the info
-Jason