1994 5.7 starts then stalls
 

I have 1994 GMC 5.7 that will start and run for a few seconds then quit. Let it sit for a few seconds and try again it will start then die. Sometimes it will start fine and run. Sometimes it will start but with a backfire. I can here the fuel pump running. Any ideas?

RE: 1994 5.7 starts then stalls
 

Did you check the spark... I've seen coils going out that will give you just enough juice to get running then crap out after a few seconds. There is also another device for your timing... TSP or something like that. It will could be getting hot and throwing your spark out on the timing. I would try to run a timing light and see if just before it dies the timing doesn't change...

Is it similar to this guy?
https://chevroletforum.com/m_39560/tm.htm

RE: 1994 5.7 starts then stalls
 

It may be feul related. When you turn on the key it primes the system, but if its not getting gas after that then it will run a few seconds thendie.

RE: 1994 5.7 starts then stalls
 

I have this same problem on my '98 Chevy K1500 5.7. It only does it maybe once a week, on cold mornings, and only takes 3-5 times before it will stay running. But it is getting worse and starting to make me think I will have to address it sooner than later.

I haven't started looking at what the problem might be. I have about 87,000 miles on it with no major changes or upgrades, and without changing the spark plugs, wires, or anything in the electrical system.

Any suggestions on where to start? And is the fix something a shade tree mechanic can do by himself with no helpers?

Thanks in advance.

RE: 1994 5.7 starts then stalls
 

jp.diddy. I would probably start with a tune up. Its pretty straight forward.

RE: 1994 5.7 starts then stalls
 

By the way, welcome to the forum jp.diddy!!

RE: 1994 5.7 starts then stalls
 

Thanks.

RE: 1994 5.7 starts then stalls
 

you may also want to change the fuel filter, if its clogged, you would have enough fuel to start, but it would soon starve out

RE: 1994 5.7 starts then stalls
 

I have the same problem as matt with my 94 except mine doesn't backfire. It seemsto onlydie at an idle.It always does it when I have it in gear with the brake pedal pressed.I put a new fuel pump, filter, map sensor, plugs, wires, cap, and rotor. when it dies the fuel pump is still running.I got tired of working on it so I quit driving it for about 6 months. I am ready to start driving it again and get it fixed. I got a new oil pressure sensor for it but havent had the time to put it on and I really don't know where it is. I've also heard that it could be the pick up coil too. Any help would be great. thanks

RE: 1994 5.7 starts then stalls
 

guys try your iac it opens and closes as need be at ildel, almost like youre tps. but also sounds like the ign control mod youre locl az can check it for you. good luck