i went to the dyno the other day and the car pulled fine all the way to 5300 rpm, then between 5300 and 5400 rpm, it dropped off 90hp. it was an almost vertical drop on the graph. after 5400 it started back up again, the guy who owned the dyno thought i let off the gas it was such a sudden decrease. scanmaster showed nothin abnormal, tps still running 100% good A/F on my o2's and on the wideband. the only thing i can see that is related to the power loss is that no matter how much timing i pull out of the motor at 5300, the knock sensor still pulls 5 degrees. It started at 39* and the knock sensor made it pull 5 degrees, after 4 pulls i ended up taking the timing down to 30 degrees, and it still was pulling 5* out of the car. all 4 pulls the power loss was in the same exact spot...Im thinking spark scatter or something else messed up with the distributor, coil mabye? its a new msd one so i doubt its bad....anyone have any ideas as to what it is?

 

wow thats' weird... hows the driveability..

 

driveability is just fine, you can feel the power loss, but i thought it was going to find something off in the tune, thats why i wanted it on the wideband on a dyno, but i cant figure this out

also, the car as a whole is low on power, all the stuff in the sig, and it only put down 303 rwhp and 320 rwtq. the a/f was not too far off, but not perfect a little scattered but no higher than 13.3 and no lower than like 12, and other than the timing pulled right at 5300, there was no other knock...it was on path to put down 400 to the ground if it kept pulling to like it was, but it never did get that high.

 

bump...anyone? i dont want to buy a new opti and have that not be the problem...

 

okay, someone please help, i just got done replacing the opti with a dynaspark unit, and the power loss is still there, not as bad, but definatly still there...i dont know what else to do...i do know the power loss is spark related because scanmaster showed innacurate timing (ie. timing wasnt what i had it set as...set at 34, running at 38) and it also showed rpm jumping randomly (looked someting like this.. 5275, 5300, 5250, 5400, 5375) as the speed was increasing the whole time completely linear. Also, im getting detonation no matter where i set the timing...i had it down to 29* total advance