Vehicle stalling, restarts randomly drives again

YUKON DWIGHT

MEMBER
2004 GMC YUKON
8.1L
V8
4WD
AUTOMATIC
160,000 MILES

The SUV stalled at a stop light with a full tank. Mechanic #1 replaced the forward tank fuel pump with OEM unit. Stalled again. Mechanic #2 said bad fuel and replaced with a second OEM unit. No codes produced either time. Mechanic #2 had all the high tech diagnostic tools and says all items tested good so the fuel /evap lines were replaced. Failed again. I found liquid fuel in the EVAP container so I replaced that with a new OEM unit. It tries to start but acts like there's no fuel supply but but it has a half a tank of gas at least. Mechanic #2 had left the bolts partially unscrewed on the tank to continue troubleshooting so when the tank fell out on the ground on the front strap cell off, I got a new boat and tightened both straps to the max. The truck started and drove home the failed again within 20 miles. I did notice at this point that the fuel gauge became somewhat erratic going from actual fuel level to even turning on the E Light randomly. After reading about potential problem with overfilling the tanks I replaced the evap canister because it has a small amount of liquid gas in it. It tries to start but still acts like it's out of gas. Help!

3 Replies

KASEKENNY

MECHANIC
18,907 POSTS

I can almost guarantee that this is a purge solenoid. If you found fuel in the canister then that will breakdown the charcoal in the canister and it will travel with the fuel vapor up the line and clog the solenoid.

https://www.2carpros.com/articles/engine-stalls

I would suggest removing the solenoid and making sure it is clean and will move. You should be able to look inside it and find out if there is anything that looks like soot or dark chalk.

If there is then the solenoid is stuck and allowing fuel vapor into the intake and it floods the engine. Or it is stuck closed and it is too lean but normally sticks open.

I attached the process below, please run through this and let us know what you find.

Thanks

Images (Click to make bigger)

SPONSORED LINKS

Was this

answer

helpful?

Yes

No

Thursday, August 12th, 2021 AT 5:09 PM

YUKON DWIGHT

MEMBER
1 POST

Thank you. I replaced the cannisters to no avail (before I got your message). But I dropped the fuel tank and started poking around and I found the connector to the fuel pump had a loose pin (actually the female receptacle to the blade pen on the pump). I could wiggle it and make it fail or wiggle it and make it work so I think I found my culprit! So impressed that you guys considered this or you personally or whoever did the thinking about it because that's exactly what I was going to do next check two valves associated with The Purge and the evap solenoids. Hopefully I'm at the end of this 4-month adventure!

Was this

answer

helpful?

Yes

No

Friday, August 20th, 2021 AT 6:57 PM

KASEKENNY

MECHANIC
18,907 POSTS

Great info. I agree that it appears you found it. The fact that you can get it to work and fail shows you got it.

Thanks so much for coming back and updating us. Please come back to 2CarPros in the future.

Was this

answer

helpful?

Yes

No

Saturday, August 21st, 2021 AT 5:18 PM