94 Blazer runs for 20 seconds then dies .
 

I have a 94 full size Blazer that had a new crate motor installed a year ago and ran great . Last week after driving 15 miles it died and wouldn't restart . Left it sit over night and it started right up . While driving home it died again but started right back up . Replaced the distributor cap and ignition rotor . Started truck and it ran for 20 to 30 seconds just fine then died and wouldnt start back up . Waited about 10 minutes and same thing , ran 20 to 30 seconds great then died and won't restart . Any thoughts ?

Have a look here - happened to me. I hope it helps

https://blazerforum.com/forum/1st-ge...-issues-88399/

Have you gotten any answers for your problem yet? It sounds exactly like what I've been dealing with on my 1992 Vandura with a 350 TBI. I had it parked behind my house for several months and when I went to start it up again it would only run for 20 seconds at a time before it died. I got distracted with other projects so I never finished diagnosing it. What I did find out was that the power to the fuel pump was cutting off after 20 seconds which was why it was dying. I checked for power at the oil pressure switch and that's where I found the power cutting off. Let me know if you've found anything out about your truck as I'm curious if it might have some bearing on what's going on with my van.