i have an 89 chevy blazer with a 350 engine. i bought it from a guy test drove it, ran fine, drove it about 60 miles back home no problem. the guy said when it rains it has a hard time starting... the first time it rained it started right up but would skip every now and then. i took it to get inspected, passed. got the tag and title for it. on the way home i was at a light and it started sputtering and died, after about 5 min of starting it, it finally started. drove it for a mile and it died going down the road. hasnt started since. ive checked fuel pump, good shape, changed fuel filter, fuel pump relay and fixed some kinks in the fuel line, the fuel pressure is 13 psi, and fuel pressure regulator. ive also changed the entire distributor coil pack, and plug wires. the problem im having is that when i turn the key the pump doesnt prime. but when i jump out the relay it primes and i can hear and see gas getting to the tbi. but its not going thru the injectors. ive tried starting the truck with the relay jumped still no luck. so whatever the problem is i dont get power to the pump and the injectors when the key is turned.. i can get it to fire up with starter fluid but it wnt stay running because it doesnt get constant fuel... ive heard that a bad oil pressure switch can cause the pump not to run but does that have anything to do with the injectors not firing as well or am i even in the wrong ball park.. somebody please help me ive spent too much time and money and nothing is happening plus im starting a new job in 3 weeks and need it to be running by then thanks

 

i dont think the oil pressure switch matters for this vehicle but i could be wrong. i have a 90 and the pump primes for a second or two when turning the key on, unless thats what keeps it running. i had a goofy issue with mine when i got it where it would misfire around and drop time, i did the same thing as you started changing everything, i finally swapped out the computer and that fixed the problem.

maybe the cowl is leaking onto the computer connections or the computer is shorting out due the water or something. the computers are pretty easy to swap out, maybe just get one at a junk yard and swap it in

 

what do you mean the cowl could be leaking? cowl?... ive got about 3 more guesses until it goes to the shop (put a new ECM, oil pressure switch, and a new computer) it will probably be the last thing i change or not work at all. ive pretty much eliminated the major stuff so its probably something small...hopefully...if its not any of those 3 i give up lol... the oil pressure switch i think runs in series so my theory is that if it reads no oil pressure then the fuel pump wnt run so if the oil pump doesnt run then the injectors will not fire. im probably wrong but in my head it sounds good..

 

like in front of the windshield leaking down inside the cab onto the computer behind the glove box. its a long shot but just a little idea. when you pull the glove box out it should be back there... at least i think its back there i got a 90 pick up which is a slightly different design then the k5s