Was not fuel pump. i now rebuilt throttle body and fuel pressure regulator and still didn't fix it. Its driving me crazy lol

 

which sensors could go out and not throw a check engine light?

 

When you rebuilt the TBI did you use carb cleaner in all the vacuum ports? Mine had a lot of build up and was restricted. Check your Throttle Positioning Sensor also, as well as your EGR Valve! I originally had your same problem, replaced almost every sensor, intake manifold, rebuilt the TBI, replaced fuel pump and fuel filter, checked engine compression which was not too bad truck had 150,000 and when all of that failed started over back to the EGR and after careful examination and cross referencing parts realized the after market EGR I bought was the wrong one! Not my fault the guy sold me the wrong part, it happens though..

 

I've got a 95 and my map sensor is in the same spot.



OP; check your catalytic converter. It might be clogged. Try hittting it a few times. If you hear things rattling inside it's bad.

 

Isn't that in the back by the distributor??

 

GM mounted the MAP sensor on the ESC mounting block.I had a 90 tbi350 and was mounted next to the esc.All of the tbi's ive seen where the same.

 

figured out it only does it with less than a quarter of a tank. Guess ill keep a full tank

 

Temp sensor I believe... it will read -40 and you'll run rich, no light if I recall right.

 

Check the egr valve .mine did it got tired of it all was stalling and driving like ****...so try it.take it out and blow on the tip see if the valve in side move if its a no go the replace