Horrible idle, little vacuum, and misfires

pearl95sc

Registered User
Okay, I'm stumped and need some other input. I finally finished putting everything back together again on pearl. I fire it up, and there is a light miss. So, against my better judgement, I take it out for a cruise to the city and back, maybe a whole 40 miles at best. Early on, the thing was moving great, I even ate an older notchback stang with ease. Now, as the night went on, the idle quality got worse, and more worse, I started to get shudders at the 5# of boost mark and up, but the car still had descent power. Today, I try to figure out what happen, and I'm still stumped. So far, I ohmed out the plug wires, borrowed the plugs and wires from my 94, checked for any vacuum and intercooler leaks, and have come up empty handed.

Last time all was together, the car ran real smooth, but it did have some quirks. During re assembly, I installed new lifters, the correct length pushrods for my regrind, my randy baker manifold/plenum, bhj and underdrives, brina herron chip and my magnecore wires. I can't think of anything else that would be causing my problems. With the plugs and wires from my 94, the idle quality did get a tad better, but there still is a miss, almost how it was begining of last night. On the stock gauge, vacuum sits at around -3hg, and on the pillar gauge it is about -6hg. When I pulled my plugs, they looked dark as if there was a rich condition. I haven't check fuel pressure yet, but before, I wanna say I set it at 38-40 psi when all was good previously. I also beleive that my problem is originating from the drivers side bank, because upon cold startup, that side gets really hot while the pass side only seems warm. Also, before swapping plugs, when the chip was in, the car was backfiring when i would revv it up at idle.

Any and all help is needed and is much appreciated. I'm ready to rip this v6 outta here and drop in a blown 331. These problems are getting to be quite rediculous.

Just checked fuel pressure, sitting at 38#'s w/vacuum line on regulator.
 
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Oh boy it could so many things but Have you changed out you fuel pump and filter. You need to know where your fuel pressure is a WOT. Should be like 48-52 psi if memory serves me right. Any codes, clean air filter, fresh gas? These are just shots in the dark. Keep me informed. Mark
 
If you have a code scanner I can borrow mark, it would be much appreciated. I did have the CE light going on and off here and there. I think the o2 sensors may be toast as well, so that may have something to do with this.

On another note, when I said that I swapped the plugs from the 94, i just did the drivers bank, I went back out and checked the pass bank, two were soot covered, and one looked great. I swapped the other 3 plugs in, and its idling better, but there still is a borderline miss. Throttle response is awesome now, but I also have exhaust leaks to clean up at the collectors. What really chapps me arse, is that those were them friggin $40+ iridium plugs, what a waste. Is there any way to save them? I got the tips soaking in gasoline at the moment.
 
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