So this is my first post on the forum and I am very much a rookie at this. I had Steve Williams (Frost) give me a mail order tune for my powertrain and during the course of the restoration, I took it for several short drives and it ran fine every time. Now that it's done, I had been driving it to work several times and it ran fine. I even bought HPTuners near the end of the restoration because I was curious how it was running. STFT's and LTFT's were all 10 or less so I kept driving it.
Fast forward to last week when I was cruising and all of a sudden it started running rough. Specifically, popping and stumbling and a loss of power under light to moderate acceleration. I went back home and backed into the garage and it smelled like it was really running rich. I checked all the plug wires and cleaned the MAF sensor and got the MAF dialed in and was moving onto VE table tuning in hopes that it would get better but it only got worse when I went to adjust the VE Table based on log data. It idles fine and goes into WOT okay too. One thing I was wondering is if my MAP sensor is okay - it reads 25 inHG at idle and key on engine off, but shouldn't it be closer to 30? I'm at 4,600 ft. I also noticed on my most recent log that bank 1 was running pretty rich under acceleration.
A few details: 2004 LQ9, BTR Stage 2 truck cam, beehive springs, cold air intake, shorty headers, no CATs. Stock intake manifold, stock injectors. New MAP sensor.
I have several logs and tunes I can upload. I have the base tune from Frost, a tune with the MAF dialed in, and a tune with my 2nd attempt at the VE table. I also have logs of these tunes, so let me know which ones I should upload.
Like I said, I'm new at this so I appreciate any guidance on troubleshooting. I thought I had a great running engine and then all of a sudden it started running poorly.
I have a feeling my Spectra MAP sensor might be an issue so I've ordered the ACDelco replacement. With key on engine off it reads 25.2 inHg (85kPa) for some reason when in actuality it's closer to 29.77 inHg (100.8 kPa).
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