1999 5.7 Engine Stall

[gburg006]

1999 C2500 Suburban 5.7
106,000 miles

I had an issue one day where I came out of the store and went to start the truck. It would turn over but would not start. I know it had less than 1/4 tank but didn’t think I was out. Gas was my next stop on the way home. I ended up getting my dad to bring gas. Poured in maybe 3 gallons of gas and the truck started up. I went to the gas station and filled it up.

A few days later I head to work. The truck ran for 10 minutes and then died in the parking lot when I was getting coffee. After 20 minutes of sitting I was able to start it and rushed to get it back home.

I already had a new Delphi fuel pump so I figured it was time. Pulled the tank, replaced the pump, installed, and started the truck no problem. Drove home with no problems at all.

The next day I grabbed my trailer and was heading to my shop to do some work. I made it up a very gradual incline and over the hill. When I got to the bottom and applied more throttle I was pretty stumped when the truck didn’t make a noise. I coasted for maybe 1/2 mile and eventually pulled over. 10 minutes of waiting I was able to get it to start (stumbled and then started).

So what is the most logical option. I have gone from is it just a relay (have not done that yet), to fuel pressure regulator, to bad poppet injectors. What is the most logical reason for my issues and what should I be testing?

 

[Chevyman1969]

Although you did a fuel pump and hopefully a new filter and it seemed to help the issue I feel you are having is a faulty ICM (ignition control module) they act up once they get hot so of course stopping and it has a chance to cool off they will generally fire back up until hot again.

 

[Schurkey]

1. Verify fuel pressure when it cranks but won't start.

2. Verify spark with a spark-tester calibrated for HEI when it cranks but won't start.

 

[Cadillacmak]

I am not sure about the 99, but I bought a 96 k2500 Suburban dirt cheap years ago from a volunteer fire department because it was doing that. Had some other issues, but that turned out to be the fuel pump relay, would run till the relay got hot and the stop (which was random). Had bad connections at the relay from heat too. New relay and a little twist on the prongs, and we drove it for years.

 

[gburg006]

Update: just to make sure, I replaced the fuel pump relay. I started the truck and it ran for 20 minutes and then died. The truck would crank but not start.

Does that help narrow down anything? I am hoping to dig into it this weekend.

 

[John DeWitt]

Did you replace the fuel filter?

 

[Cadillacmak]

I need to learn to explain better on here, some of you are the boss at that. How I found it was the fuel pump relay is I ran it till it stopped then felt the relays, fuel pump relay was warm so I swapped relays and it started right up. Not a fan of the parts cannon, diagnose and repair. Only time I parts cannon is when it needs refreshed.

 

[gburg006]

I need to learn to explain better on here, some of you are the boss at that. How I found it was the fuel pump relay is I ran it till it stopped then felt the relays, fuel pump relay was warm so I swapped relays and it started right up. Not a fan of the parts cannon, diagnose and repair. Only time I parts cannon is when it needs refreshed.

I agree. My issue was not the fuel pump relay though: replaced and died in about 20 minutes.

Im thinking ignition module or coil. Could I expect a code on a failure like this?

 

[Cadillacmak]

You might not get a code on a coil that is failing, look up the resistance parameters of that coil and check it out with a meter. If its outside those parameters, you may have found the problem.

 

[gburg006]

Not the coil or ignition module. Replaced those and now it won’t start at all.