1990 ls teg problem

[90lsteg]

i can drive the teg and out of nowhere it will just start running like shit. i check my wideband and something (i think its the ecu) is cutting my fuel but if i slam the pedal im guessing it overrides the ecu and dumps fuel into the motor and it pulls again but not instantly like it should. motor is brand new with only 400 miles on it. current ecu is a pr4 that is chipped and reflashed to run turboedit. i have plenty of spark cause i have a new 6AL. my fuel pressure gauge is reading about 42ish psi. the car messing up is very inconsistant. as i was breaking in the motor on both occasions i hit 100mph i stayed in gear and let the car slow down on its own (heard doing this letting it build back pressure helps set the rings) i got a check engine light and my fuel became really lean. now it does it whenever it feels like it. any suggestions? if someone can help me fix this really quick ill hand out a small reward

 

[Justin66]

Fuel clog maybe, injectors could be fouled up, same with the spark plugs.

 

[90lsteg]

new 6al box
new msd dist cap
msd wires are pretty new
new spark plugs

my guess is maybe the fuel pressure regulator is shitting out on me. im not sure if they go out at once or over time. and my fuel pump is 18 years old. i already fixed most of the problems with the car. i took a good look at it in the sun light and the connector broke the the o2 sensor.

BUT

Everytime i drive over 100mph my check engine light comes on and runs like poop and if i turn it off and then back on poof problem fixed. suggestions?

 

[Justin66]

The regulators can go from time to time. You can get em cheap or get an adjustable one. Replace the O2 sensor and your car should be running good again. One bad sensor and your whole car gets screwed.

 

[90lsteg]

i'll replace the o2 sensor,rebuild the regulator, and new fuel pump and see where it stands. currently have an adjustable aem fuel rail and regulator rebuild kits are only 45 bucks

 

[Justin66]

Nice, but i dont think your fuel pump is bad but you never know.

 

[boost_me]

dude i hade the same problem i change the plugs, wires, rotor button, cap, fule filter, pressur regulator, cleaned the injectors and havent hade a proble since. a hard core tune help me maybe it will help you

 

[Justin66]

Its what im due for. Just need some new wire and fuel filter.

 

[spoondb2]

sounds like a bad chip or ecu

 

[90lsteg]

i have a stock pr4 ecu put that in and it was worse. new fuel filter same thing. but we figured it out. missfire on cylinder 1 cause the injector shit out on me. its always one thing or another. but i though if a fuel pump went out it would go all at once. getting a new one of those too. thanks for all the help guys