Hoping to get some insight and help as I'm new to the tpi systems and really want to make it work.
88 iroc z 350 tpi & 700r4. Mods, air pump delete, shorty headers and spectre cold air intake, not oiled.
New parts, maf, burnoff relay, maf power relay, fuel pump relay, injectors, distributor, ecm, fuel pump, fuel pressure regulator, MAT sensor, plenum and runner gaskets, tb gasket, fuel lines & fuel filter.
Verified proper fuel pressure at the rails, tps is functioning properly, no vacuum leaks
Problem is, out of the blue my car will not stay idling or take throttle. Was daily driving it perfectly fine for a week straight, parked for a few days and now poof, issues out of the blue. The car will start right up but then immediately die, or try and idle, then die. Sometimes it'll rev up to around 1200-1500 rpm then back down and lug, then rev up but it'll eventually just die. When giving throttle, it will either die immediately or will bog down real bad and backfire out the intake. Happens the same regardless of gear and can not get it to take throttle enough to move but a few feet at a time if that. Dual exhuast, alot of fuel smell and "moisture" coming out of the tailpipes. I'm at a total loss, and thinking of removing the tpi system as ive had nothing but issues but would like to keep it if I can get it fixed. Any and all help is appreciated.
EDIT: Also forgot to mention. It will not throw a code unless I hold the throttle down and allow it to bog and backfire for a while, only code given was 34. Tried unplugging the maf and no change. Swapped between 2 good mafs and swapped many good relays around with no change

 

I think that I would start by checking for vacuum leak(s) and/or false air. Then I'd test the MAF harness for a short to ground. Backfiring through the intake is an indication of too lean a/f ratio. It's not getting enough fuel, either b/c of lack of fuel delivery (low fuel pressure) -which wouldn't likely throw a code 34....or b/c of a bad signal from the MAF, which could throw a code.

 

Here is some work, for you....

 

What manufacturer and part number MAF is installed? There has been a rash of less-than-accurate MAF sensors being sold recently (the last 15 years) for our TPI systems.