A quick update, I tanked up and put 3 more oz of Lucas fuel injector cleaner in the tank and the H3 stumbled and stalled four times. Each time I turned the engine off and removed the key. Twice I even shut everything off, locked the car and unlocked it via key fob and reentered the vehicle to start it...still stumbled. I got frustrated after the fourth time it, so I started it again and it only starts to stumble once in gear...in park each time it was fine. So I put it in gear and let it start stumbling then to park where it continued to stumble. I floored the gas and then kept it around 3,000 RPM for 15 seconds or so and it smoothed out. I did it again...3,000 RPM for 15 seconds and let off...it was still smooth. It ran well and I drove it home (from 2.5 hours away) and have run it the past 3 days with no issues. I think I am going to take it to the dealer as I cannot find anyone locally to scan the computer. I have no idea what this is, if it is a fuel injector it looks like it would happen more often, same for the computer and a vacuum line. I will let you know what the dealer finds sometime this week.

 

I went to the dealer today and they had never heard of this happening before. They ran a diagnosis and found nothing wrong. They suggested to replace the EVAP Purge Solenoid Valve and clean the entire fuel induction system. After completing all this I went to get gas as it was on empty, and the engine stumbled after shifting to drive. I made it to a parking spot and cut it off, and back on where it stumbled again. I revved the engine to about 3,000 RPM and it smoothed out and I drove the approximate 40 minutes home with now issues. The dealer said from his end the PCM is good, the fuel pressure was good and with the fuel system being cleaned he has no idea what is happening. Any ideas?

 

Didn't you pay them to diagnose the problem? Sounds like charged you for some unneeded work and didn't even take the time to fully troubleshoot the problem. I would definitely complain. Sounds like a Jiffy Lube type scam.

 

I dont understand why they replaced the purge valve considering the vent valve is a common issue with GM?

Question, when you refill, do you fill until the pump shuts off? If so, next time you add fuel, just try a few gallons or so(don't go over 3/4 on the gauge) and check if your issue still occurs.
It appears the engine is getting "flooded" and you have to "clear flood" when this occurs. That could happen when overfilling, causing fuel to flow into the canister.

 

Thanks for the advice, I just realized that I need to fill the tank less than full next time. Each time before I have filled up and let the gas pump shut itself off, so that could be the issue.

Help me understand what a clear flood is, is that where fuel goes into the Evap Canister and gets stuck?

And when you reference the vent value, is that on the gas tank?

Thanks again! I hope this puts me on the right track.

 

"Clear flood", is when your cylinders have excessive fuel in them and you depress the accelerator pedal (burning the excessive fuel) until it burns off and clearing the cylinders.



An evap system consists of a small canister full of charcoal, valves, hoses, vents in the fuel lines and a sealed fuel tank cap. When fuel evaporates inside the gas tank, the excess vapors are transferred to the charcoal canister. They're stored there until they can safely be transferred back to the engine to be burned with the normal air-fuel mixture.
When that's ready to happen, a valve creates a vacuum that draws the vapors into the engine. Fresh air is also drawn in through the vents and valves to mix with the vapors for better combustion.

 

Great, that helps alot.

Forgive me, I have worked on a few vehicles before but not the evap system. The dealer replaced part 12597567 which is the purge valve. But you are saying I need to replace the solenoid valve (part number 4 here: http://store.gmpartshouse.com/parts/...agramCallOut=5

If that is the case I am reading you can buy one with the tubing for $130 or one without the tubing for about $25. I am trying to verify part numbers, can anyone assist with this?

Any additional input is valued.

 

I cant assist, but I had to have mine replaced. I had a check engine light on though. Evap vent solenoid was replaced. It is easier to mess up if you run the vehicle while fueling up. They said it sucks exhaust in and gets stuck I there or something. Sorry about no part # it was one of the very few things the dealer has done to mine. Before I realised they were rip offs.

 

Update: I ran my gas down to almost empty and put in 10 gallons (half tank or so) and the Hummer did fine. No stumbling as I drove off from the gas pump or any tach abnormalities. I am going to put a half a tank in the next few times I need gas to make sure the problem does not reappear. I spoke to a neighbor that has a mechanic background and he recommended to replace the vent valve next to the gas tank as well.

I will update this post over the next few weeks with my half tank fuelings. Thanks for all the help.

 

ACDelco 214-2147 connects with factory connector



ACDelco 214-2324 (revised part) requires jumper harness 19257603