I have a 91 4.3L tbi Blazer that won't stay running. It was working fine then one day I left it sit at idle and when i got in it, it started missing and died. The next day I went back and I got it running (it was around -15 degrees C) and got it almost all the way home and it died again. What it does now is it starts and idles high for a few seconds then it drops and dies. I can keep it going by giving it gas but it eventually backfires and stalls. If I floor it the engine bogs down and tries to stall.
I have changed:
fuel pump
alternator
TPS
EGR valve
plugs, wires, cap and rotor
ignition coil
I've gone through several new throttle bodies and injectors (all used but in visually good shape)

I recently took the plugs out and they were fouled so I'm guessing the motor is running rich and this might be why it is stalling. I'm almost completely out of ideas, hopefully someone knows whats going on.
Thanks!

 

So now that its warmer out I finally figured out the problem. I checked the fuel pressure and I was getting zero psi. I didnt quite believe this since i could still get it running. After testing I narrowed it down to the tank, which is weird because I just replaced the pump and assembly. Turns out it wasnt weird at all. A bit of advice to anyone changing these parts: the hose connecting the pump to the line inside the tank is garbage. change it for another one and it will save you the trouble of redoing the whole thing. Another tip is to cut a whole in the floor above the tank. This might sound extreme, but it makes working on the tank 100 times easier. Now I have to re-enforce the floor but its better than dropping a 3/4 full tank. So if anyone has seen this post and wants an answer there it is.

 

Lol I did the same thing cut a hole.i left about an inch so all I do is lift the flap .half hour and ive changed pump.Ya ive put about 4 pumps in just becouse there warranty lol,found out this last summer how a simple ground wire in the rear of the ridge is .had no pump changed it nothing.Then I thought ground wire so i put a nut on bolt tighted it down fixed my problem.Until a coulple days ago .I was checking out my new tires up in the woods and lost power.It would start go about 50 ft die start right back up .I made it home 3 hrs later dam that sucked its was dark when it happen made it worse.Anyway ive change spider dam everything i can think to do .All it does now is start idle great press gas dies . So first time in my 47 years i took it to a shop.We will see tomarrow