‘99 K2500 died and won’t restart

[Aholter90]

This actually happened way back in September but I had a family emergency and haven’t had time to work on the truck til now.

So, I was driving my ‘99 K2500, literally the first time after the new exhaust, ign coil, cap, and rotor installed, and it was running fine. About 2 miles from home, the truck dies and won’t restart. I towed it home and then life got in the way.

Now that I’m back on it, here’s what I’ve determined. Fuel pump is turning on. It is getting fuel, but won’t start with either fuel or starting fluid. I pulled the cap and the rotor is turning. No check engine light, at least not when the truck first died. Actually didn’t pay attention to it today. The truck cranks but it sounds uneven, like a pulsing. Haven’t done a compression check.

If I had to guess I’d suspect the timing chain jumped. This happened to my ‘96 about 6 years ago, but I’m not sure. Any thoughts or suggestions?

 

[OutlawDrifter]

Does it have fire? After doing the ignition components, that would be my first area of focus.

 

[GoToGuy]

You have fuel, is pressure adequate? Then rather pulling cap, pull spark plug wire, getting spark? Yes or no ? No spark, start with why no ignition.
Unless you have a witnessed catastrophic malfunction always start with the basic, that will show witch path to follow.
If your presuming you have adequate fuel pressure,but no spark, I'd do a scan for codes that didn't set ses light. Then start troubleshooting why no spark.
Good luck.

 

[Aholter90]

I should add, this is a ‘99 with the 5.7 and 4l80e

 

[Nad_Yvalhosert]

Now that I’m back on it, here’s what I’ve determined. Fuel pump is turning on. It is getting fuel,

What is the fuel pressure? Vortec engines need 60-66 psi. Less than 55 will not run well, if at all.

but won’t start with either fuel or starting fluid.

Suspect ignition then. Have you checked for spark?

The truck cranks but it sounds uneven, like a pulsing. Haven’t done a compression check.

Check the spark plugs, seeing as it's been sitting 4 months.

If I had to guess I’d suspect the timing chain jumped. This happened to my ‘96 about 6 years ago, but I’m not sure. Any thoughts or suggestions?

If the timing chain jumped, you'd have a cam/crank correlation error, which would set a code.

 

[454cid]

My guess would be the ICM.

 

[Schurkey]

No sense guessing until more diagnosis/testing has happened.

As said, verifying spark is probably the #1 priority at this point. I would use a spark tester calibrated for HEI on the coil wire. That verifies the crank sensor, coil, some of the ignition module, some of the wire harness, some of the ECM.

If there's good spark on the coil wire, test spark on the plug wire for the misfiring cylinder(s). That verifies rotor, some of the cap, and the plug wire(s) being tested. If you have good test results on at least two plug wires, you can be reasonably assured that the distributor is turning. Testing with the spark tester does NOT verify that the plugs aren't oil or fuel fouled, or the porcelain isn't cracked. But it would not be reasonable to expect eight cracked porcelains unless the last guy to work on the engine was Godzilla.

You say it's "getting fuel" but you haven't specified whether that means you have fuel pressure, or you know the injectors are actually spraying an appropriate amount.

That leaves "weird" ignition issues, compression, and (plugged) exhaust as potential causes of a non-running engine. Compression needs to be under 80-ish for a cylinder to not run. Usually, a plugged exhaust will still allow a couple of cylinders to fire, even if the engine won't run.

 

[letitsnow]

You might also want to load test your battery. I had a bad cell in a fairly new battery that was making weird stuff happen - It still cranked the starter over fine. Have also had bad gas cause a no start issue on a vortec 5.7.

I have never seen over 60 psi of fuel pressure on any of my vortec trucks - always 50-60. Could just be my gauge.

 

[b454rat]

Check the distributor? Bad gear will give all those signs.

 

[Aholter90]

Thank you for the responses, guys. Haven’t tested fuel pressure. My first guess was distributor but I have confirmed it is turning. I haven’t tested for spark other than to hear that it is not firing. The uneven cranking it what most concerns me and that’s why I’m leaning towards timing chain issues. When I get down to the shop today I’ll check to see if the SES light has come on.