350 tbi just starts but shuts off

[boostn54]

have an 89 k5, 350 tbi, truck started to act funny last week, replaced the wires plus and distributer cap last week and now the truck starts but shuts off immediately

have 2 quetions,
1. my buddy says its probably lost oil pressure(gauge doesnt work) any other ideas if thats not it

2. looking at getting another motor if thats the case(dont want to mess with the bottom end) found a 350 tbi with 90k on it, starts right up runs fine for 3-4 minutes and just cuts off, anybody have that problem or know what it might be, trying to find this out before i shell out 350 bucks for another motor

 

[496truck]

If you didn't have enough oil pressure you would know it.

Just off hand, sounds like the fuel pump is junk. Running for a few minutes and then seizing up. This is assuming that after the truck shuts down it will not restart right away or any time soon. Quick way to check, run truck till it shuts down. And right after it quits turn the key off and wait a few seconds (like 10) then back on. Listen for the fuel pump in the tank to come on with the key. May take 2 people to do this, one to turn the key the other to listen to the tank.

Fuel pump relay can also act like this but I think there is a failsafe for that.

Ignition module can also get hot and shut down.

 

[4X4HIGH]

have an 89 k5, 350 tbi, truck started to act funny last week, replaced the wires plus and distributer cap last week and now the truck starts but shuts off immediately

have 2 quetions,
1. my buddy says its probably lost oil pressure(gauge doesnt work) any other ideas if thats not it

2. looking at getting another motor if thats the case(dont want to mess with the bottom end) found a 350 tbi with 90k on it, starts right up runs fine for 3-4 minutes and just cuts off, anybody have that problem or know what it might be, trying to find this out before i shell out 350 bucks for another motor

My guess is you got the wires on the cap wrong. Pull the #1 plug and crank over to find TDC then see where the rotor points and put #1 wire there then run the firing order in a clockwise rotation. It never ceases to amaze me how many people ASSUME where the #1 wire goes and just puts it there when in reality someone in the past could have installed the distributor wrong and where the #1 wire SHOULD be is really no longer where it is.

 

[boostn54]

thanks ill try both those, rushing to get this thing ready for uwharrie in a week and a half

 

[JPOutfitters]

did we ever figure this out?

 

[Vetteracerx]

IAC motor? Will it stay running if you open the throttle blades? Or if you spray silicone in the TBI?