2002 HD 8.1 In Shop

larryboz · May 24, 2002

I wonder if anyone else is having the same trouble I am. This is what happens I am driving down the Road and the truck just dies doesn't matter which gear I am in or how fast I am going. Doesn't do it all the time, then when I come up to a long stop at a light or something and let the truck idle the engine will just start idling rough and shaking the whole truck. It has been at the dealer for 4 days now they at first said they had no idea but replaced the No. 7 injector and the computer said it was fixed wanted to keep it an extra day to make sure. Called me this morning and told me to come pick it up it is fixed so I get into drive 3 miles it dies again so I immediately trun around and take it back the dealer is at a loss they have no idea, so now my truck sits while they scratch their heads. Does anyone have ideas? It always starts back up. This is not what I paid 30K dollars for. It only has 6000 miles on it. It is not the gas I have run several tanks through it and filled up at different locations for the past 3 weeks. It is progressively getting worse.

Larryboz

bassdog · May 25, 2002

Sounds like the computer is slowly dying or shorting. Have they mentioned changing that yet?

larryboz · May 25, 2002

Yes they have replaced the Computer and the No. 7 Fuel Injector. I think there could be a loose ground somewhere

silverado3500 · September 17, 2002

Check the Fuel Pump, that may be the culprit.

CMNTMXR81 · September 25, 2002

If it were the fuel pump, it'd be difficult to start. Once it was runnning the engine would provide enough vaccum to suck a sufficient amount of fuel up.

Does this happen shortly after starting the truck cold? If so, there is a PCM re-flash available for this. Mine does it too, I keep forgetting to re-flash it everytime I have a TechII though.

TxDoc · September 27, 2002

Larry--check your PM's.

Brian1 · October 8, 2002

I have a 2500 Avalanche with the 4L85E Trans. This has only happened to me once. I was driving down the interstate and it just simply quit running. Tried restarting but just cranked only. Called for a tow truck and after about 20 minutes it started and hasn't done it since. Just before it happened I had gased it up and I didn't close the gas cap the way I normal do. I was talking to someone and I used my other hand not really paying attention to what i was doing.

My guess it's the gas cap. I have seen other vechicles especially 2 Cadillacs and they had them in to dealers for this problem many times. I finally told them to get a new gas cap and their problem has quit.

No rough Idleing here.

But do have one fluke ever now and then. In the morning I start the Avalanche back out of the drive and the put it in drive and step on the gas, it might hesitate like it might die. It only does once and only from a cold start.

One other posiablity was I have Onstar on mine and member of the Chevy Avlanche Fan Club said the computer could have gotten a false code the said the vechicle was stolen. Won't restart until the timer counts down. If you restart before the timer counts down it will start over.

I hope this helps.

Brian

Keith_S · October 22, 2002

I have a 2001 1500HD Crew Cab with the 6.0L. Had a similar problem. Truck always ran and started fine until I went over 100 miles straight. After 100 Miles, if I shut the truck off, I could not start it. Engine would just crank and crank. Didn't sound like it had any spark or fuel. I waited about 10 minutes, then disgustedly, I tried to start it and low and behold, it fired right up and ran fine. Managed to duplicate it several times on long trips. If I drove 200+ miles straight, I had to wait 20-30 minutes before truck would start again.

1st trip to a dealer while travelling in Georgia revealed they had no idea what it was. They said maybe a fuel filter so replaced it. Got home to Virginia Beach and headed straight to the dealer. They were good enough to loan me a car and keep the truck 100 miles round trip by their service rep and he shut the engine off and THANK GOD, it wouldn't start. It also saved several codes:

1. Loss of Communications - U1041

2. Loss of Communications - U1026

3. Crank Sensor Code - P0335

Tech assist was called and they explained all cases for this code required new crank shaft sensor. Sensor was replaced under warranty and no problems yet. Drove 105 miles, shut the truck off and started right back up.

Service guys said the Crank Sensor monitors crank shaft and shuts down all engine functions if an imbalance is detected, or if the crank stops moving. Supposed to save the engine in the case of a catostrophic failure. They also said they have heard of the sensors getting lose and shutting vehicles down while driving.

Don't know if this might have been the problem, but it seems to have fixed mine.