2002 silverado 2500HD 8.1 L gasser

Thanks for all the responses. It only has 69,000 miles on it and I bought it new.
I'm getting the oil chngd this week and I'll mention the crankshaft positioning sensor. Any idea what it costs to have the dealer do the job?

This is a classic symptom of the Crankshaft Position Sensor going bad, and is exactly what mine did when it started to fail. There was a recall on the 01-03 8.1 engines for this.

Apparently when the sensor goes intermittent, the PCM loses track of where the crankshaft is and kills the engine before it can store a code, making diagnostics difficult. The dealer hooks up the scanner and gets no active or stored codes and diagnosis stops there. Even if the dealer had the scanner connected while it was running and died, they wouldn't see any codes. Seems illogical, but apparently a quirk in the software that allows this to happen without storing a code.

When this sensor quits for good, the truck won't restart after it dies. I had mine replaced years ago by Rocky Mountain Chevrolet while on vacation with the camper.

Trust me on this one, replace that crank sensor before you get stranded. FYI, if you DIY the new sensor, you still need to do a crank re-learn with a scan tool, so my experience it's just easier to have the dealer change the sensor and do the re-learn.

lone ranger wrote:
The first hour of diagnostic tests I paid $100 for. Then I complained to the service mngr and he had tests and road trips done at their cost, and nothing failed. Until it permanently quits and won't restart they won't spend time on it but if I'm on the highway and it quits I could end up in a dangerous accident.

The dealer is being honest with you,they need to have it fail so they can test and find out what the problem is.
Being a Honda dealer master tech I deal with this type of problem often intermittent problems are frustrating.Maybe you can leave it at the dealership for a few days and let them try it at times or have a tech drive it home and back to see if it fails.
Be glad they are just not throwing parts at it to try and fix the problem without first knowing the cause.

In the absence of any codes I would suspect an intermittent dead short in the alternator or a positive cable or wiring harness grounding out from a rub thru. I finally tracked a similar issue down to that after her car left my DD a number of times. It was a weekend so I took it to Autozone for testing and when they threw the tester on it dimmed the lights in the store.
Every time it happened by the time I got there to rescue her the car started right up and drove fine. Until the next time.

My cousins 2002 8.1 did that, and it turned out to be the cam position sensor I believe.

Early model GM trucks are famous for in-tank fuel pump failures. Very common. Usually however, the problem is not intermittent. When it happens, they quit running and won't restart. Just a thought....

The first hour of diagnostic tests I paid $100 for. Then I complained to the service mngr and he had tests and road trips done at their cost, and nothing failed. Until it permanently quits and won't restart they won't spend time on it but if I'm on the highway and it quits I could end up in a dangerous accident.

loneranger...if it does turn out to be that crush washer....would you take some pictures of it still in the plastic molding and post back here ?

Want those pic's for my files for the 'next' time this happens and have pics to show'm

Sadly, many do NOT believe that and look for something much more complicated/expensive...even selling & paying tens of thousands of bucks for another vehicle

GM does sell replacement lead, crush washers. IIRC, 3 or 5 per plastic bag and not expensive the last time checked...but I'd rather not deal with that thing ever again...

Oh, mystery problems s uck.
So the dealers couldn't replicate it?
Couple possibilities. 1. An electrical short somewhere
2. Fuel pump going bad or filter/ screen becoming plugged up?
3. Check valve on fuel vent line from tank to intake. Usually only happens on a full tank of gas, but the wife's car has this issue. Fill the tank, it will sputter and die or run rough for the first few minutes then all is good. Doesn't sound like your issue, but??

Good luck. Intermittent issues are sometimes a tough go.

Thanks for the info.