Alright guys coming back to my roots here at Stanget hoping to solve this one. Recently swapped a PI 2v 4.6 with a Stroker kit into my 96 gt. Along the way I deleted my EGR because with Longtubes it's darn near impossible to put all that crap back on. Problem is I've had a little bit of a miss at idle ever since I put this motor in. The miss I can deal with but here's the real issue. The car surges and bucks under quarter to half throttle. I can't seem to get it to happen until 4 and it's bad in 5th. Weirdest part is it's pretty darn bad from 1100 to about 2200 and then it cleans up. Also if I continue to push it when it's bucking it backfires in what sounds like the headers (might not be in headers though). I've pulled the codes and there's a couple EGR codes in there and then it's showed a miss in cylinder 3 a couple times and more recently a miss in cylinder 5.
What I've tried:
Fuel filter change. Checked and regapped all of spark plugs (they're a year old). Unplugged MAF while running, car died. Replaced both cool packs *sigh*. Swapped plug wires to missing cylinder to verify they aren't the issue. Checked fuel pressure, took a little but came out to like 31 running. Checked the vacuum lines and they all seem fine. Swapped out injector on missing cylinder with a spare to verify injector isn't culprit. Also compression tested cylinder 3 and it read just fine. And lastly I have an SCT X4 on the way to shut off the EGR to hopefully fix this madness...
Also important to note with my current set up I'm getting 4 less miles to the gallon and I haven't been romping much so mileage is rough. And when I used our little code reader here at home it claims the STFT is 20% on both banks and the LTFT is 7% on both banks which from what I've read is absurdly high. I haven't tuned the car but I'm afraid to dyno tune it with current issues because I don't think a tune will solve it.
All in all I don't know what the issue is. Thought I had it partially nailed down because of cylinder 3 but now I got cylinder 5 to miss so I don't think it's a bad plug,injector, or the wiring. Could the EGR cause all this trouble? I want to naively say yes and that the tuner will fix it but it just doesn't add up. Any help is greatly appreciated.
Thanks
What I've tried:
Fuel filter change. Checked and regapped all of spark plugs (they're a year old). Unplugged MAF while running, car died. Replaced both cool packs *sigh*. Swapped plug wires to missing cylinder to verify they aren't the issue. Checked fuel pressure, took a little but came out to like 31 running. Checked the vacuum lines and they all seem fine. Swapped out injector on missing cylinder with a spare to verify injector isn't culprit. Also compression tested cylinder 3 and it read just fine. And lastly I have an SCT X4 on the way to shut off the EGR to hopefully fix this madness...
Also important to note with my current set up I'm getting 4 less miles to the gallon and I haven't been romping much so mileage is rough. And when I used our little code reader here at home it claims the STFT is 20% on both banks and the LTFT is 7% on both banks which from what I've read is absurdly high. I haven't tuned the car but I'm afraid to dyno tune it with current issues because I don't think a tune will solve it.
All in all I don't know what the issue is. Thought I had it partially nailed down because of cylinder 3 but now I got cylinder 5 to miss so I don't think it's a bad plug,injector, or the wiring. Could the EGR cause all this trouble? I want to naively say yes and that the tuner will fix it but it just doesn't add up. Any help is greatly appreciated.
Thanks