90 k1500 stalls randomly with engine light

[NealK1500]

I have a 1990 k1500 350 TBI that stalls at random times when warm.
New distributor, spark plug wires, spark plugs, ignition coil, coolant temp sensor, oil sending unit sensor under distributor, map sensor, 02 sensor. It throws a SEL light when it stalls and shuts everything down like it’s telling the computer something is of harm. Distributor, ignition coil is about 5 months old with not a lot of driving/ starting. I have replaced ignition control module as well. It threw codes for map sensor and 02 sensor replaced them. It throws service Engine light when it stalls going down the road, it will not start until you turn the key back and clear the computer and if you are going like 30+ mph while it stalls you turn truck key off and back on and it starts like nothing is wrong with the truck and runs just fine till it does it again. Could be two days, could be 10 minutes but it shuts everything down. ( Also do not know if it’s a coincidence or if it was perfect timing but the truck ran fine before I went and put exhaust on the truck did have exhaust cut off at the cats. Could the converter be plugged or stopped up causing this? ) Maybe stuck egr I can push the egr valve and my idle drops, also cleaned the IAC Valve with no change.

 

[Ron88]

Did they weld any pipes when they did the exhaust, and if they did, did they disconnect the battery?

 

[Donald Mitchell]

Fuel pump?

 

[Schurkey]

Verify fuel pressure

Connect scan tool, look for "codes", but more important--look at the data stream. Verify ALL sensors and computer outputs. Look at the short- and long-term fuel trims. IDEALLY, you'd have the scan tool connected the next time it stalls.

Remove, clean, and tighten the battery cables. Verify alternator output and battery charge.

 

[PlayingWithTBI]

Hmmm, what about the ignition switch?

 

[Erik the Awful]

Remove, clean, and tighten the battery cables. Verify alternator output and battery charge.

I had the same problem on my Suburban. It would die while driving down the road. Once you pulled over it would fire right back up. I chopped off the side posts and put a top post battery in it and never had a problem again.

 

[NealK1500]

The truck finally threw code 32. Egr Valve. I replaced Egr Valve along with solenoid, cleaned out PCV valve port on intake along with Egr port on intake with a metal clothes hanger. Mainly a lot of carbon build up on the PVC Valve intake port. So after that and the Egr Valve and solenoid and some cleaning she purrs like a kitten it also fixed my oil gauge, when it was idling low previously my oil light would come on like it had no oil pressure. It stays consistent around 30+ now.