stumbling or detonating?

[Turtle TR]

Here's what happend and is happening. On Sunday afternoon, I ported and installed a turbo exhaust compressor elbow from an 86/87 GN. Noticibly the wastegate puck arm is a little taller and I had to lengthen the actuator rod to make up for its height. I had the wastegate set to 15psi before the mod. after installing the elbow, I took the car out and blasted it on the road, even with the rod lengthend, I hit 20psi!!! Drove the car back home, nothing wrong with the car. Next morning, on my way to work, I had a slight stumble, just as the car was going into 4th gear OD at about 2000rpm, during regular traffic. I thought nothing of it. going back home, it did the same thing, but it wasnt a constant thing. This morning, it started stumbling more as I drove off. It wouldnt stumble if I got on the gas hard, and on the freeway, it started stumbling really bad at 2000rpm on the freeway coasting on 4th gear OD. One other thing, I ran xylene on Saterday for the 1st time. I had about 1/2 tank of 92 and poured in 4 gallons of xylene and 4oz of Marvel's Mystery Oil. The car ran really good on it when I raced this past weekend, though, I was thinking it was a bad mixture at the end. I'm going to refill my tank with 92 this afternoon to dilute the 92/xylene mixture. The only thing I could think of of this happening was my sparkplug wires might've been knocked loose while I was taking off the old elbow or during installing the new one, or I have a fouled plug. I'm going lengthen the rod more to see if things change. I don't know, but what I might think is stumbling, could be detonationany suggestions or ideas will be greatly appreciated.
Thanks,
Turtle

 

[Turtle TR]

I took the scanner to the car and found that there was a code 22. TPS sensor being too low. I checked the TPS voltage and I'm reading .42v at idle and 4.70 at WOT. the stumbling hasnt gone away. could it be a bad TPS or IAC since they relate to each other?

 

[Turtle TR]

I replaced my plugs, and fuel filter (as suggested by a friend) and I have reset the TPS at .44v idle and 4.79v WOT;and IAC variates at 40-50, and the stumble has somewhat gone away but it's still there, just not as harsh and it doesnt occur while I'm coasting like I posted earlier. Though now, I come to believe my MAF might have gone bad, though, I dont show a code 34. is it possible for the ECU to not detect the code if the MAF has gone bad? During cold startup and open loop, the intake sounds like its sucking more air than it should. Then, when closed loop occurs, it calms down a little, but It still has bad idle and it sounds like it's missing a little. when I throttle it in park, it sounds as if is sucked a hairball in, with a slight stall and then it picks up again. in Drive, it stumbles a little but it doesnt stall. at WOT, the car drives great, cant tell if there were any problems present. Also, I lengthend the actuator arm more and I still get 20psi. something's stuck up there? I'm also thinking the coil pack could be bad, along with the module. My dad told me that often times, that causes small misfires. I dont have a CCCI tester to see if it's bad. any other suggestions or ideas? This is beginning to be annoying.

 

[Turtle TR]

I checked for codes yesterday afternoon and found that the car was showing codes, 22 34 and 44. I fixed code 22, the voltage on the TPS was .04v now it’s .44v idle and 4.79 at WOT. I Unplugged the MAF sensor during diagnosing the problem and induced a code 34. 44 were found later in the afternoon. I have noticed the car had been running rich. The fumes are practically burning my nostril hair and my eyes. 44 could be a shorted or a dead O2. But after I reset the ECM, ran the car, and shorted the ALDL for codes. 44 wasn’t present. The car still smells rich. Also, on the freeway, I punched it to pass a slow moving bus, and shortly afterwards, the car started to stutter a little and back fire on the throttle. This was cruising at 55-60mph. Every time I’d be on the gas for a prolonged time, it starts to stutter a little then POP! Backfire. I think I read somewhere that a car can backfire if the car is running rich. Code 44 is not present, though I know by smell that the car is running rich. More than likely the O2 is bad. I’m going to purchase a heated O2. So because the O2 is bad, it causes the car to idle badly and roughly, as though it had a higher duration cam. Can a bad O2 cause the car to stutter just as I get on the gas from a stop? It’s been doing that. Also, can a bad MAF cause the car to run rich too? Please help, this is getting fustrating.