2003 GMC Yukon Denali Vortec 6000

[thedutydoctor]

I have had no problems up until now with my Yukon, until last night driving home south on I-95

I must have been driving for about 15 minutes and began to smell gas, very strong in the cabin... first I thoguht it was coming from an old van up ahead and shifted lanes..

At which point i began to decend down a long hill and backed off the throttle to keep the speed steady (60-70) I began to experiance a slight backfire, it was not real loud but I felt it more than heard it, I got louder and I thought the truck was going to blow off the exhaust system, after slowing dwon and moving lanes to the slow lane the fault slowly dissapeared, and never returned during the trip home (25 miles)... however this has just happened to me again this morning...

Recap...

First comes the over powering smell of gas...
Then a very slight backfire, with no noticlbe loss of power..
Backfire increases, and only seems to become evident when backing off on throttle or running down a very long steep hill..

Been to the GM dealers this morning and they are unable to look at this until mid next week!!! I need the truck for work Monday dude (its now Saturday morning)

I have No check engine light either during or after these events...

OK googling I hit on some similar issues with this engine and it seems to be related to the throttle body or MAF on one report, does anyone think it would be worth while to have a fuel tune up at the usual oil change depots?? like Goodyear or Pepboys etc.. I've done over 60K in this truck and never had thefuel system serviced..

Or is this a sensor issue, MAF sticking,

I

Thanks for advice.

Will in Maryland

 

[treepete]

hey Will. welcome aboard the forum. checking/cleaning the MAF yourself shouldnt be difficult.. but the smell of gas in the cabin is weird sounding.

is it possible for you to check/replace your fuel filter?

 

[thedutydoctor]

thanks treepete, I am down at the local tire service unit in Rockville now having a fuel service and clean I'll update you if they find more while under the hood, your right the smell of fuel was real strong and dissapeared as fast as it arrived...

Will

 

[thedutydoctor]

Treepete... thanks for the help...

I dropped back into the GM dealers this afternoon after the fuel service at Goodyear,

I wanted to get a couple of DLR pigtails as one was out and the holder was real brittle, while in the service and parts area I struck up a conversation with one of the service tech’s and explained my experience from last night, he wasn’t sure obviously but said that if code reader had no faults listed then a possible cause could have been a sticking open injector that would explain the strong smell of gas I suppose.. and the intermittent nature of the fault…

He recommended a fuel service, filter MAF cleaned and checked, which I’d already had done at the local Goodyear station, he also added that it wouldn’t hurt to add some injector cleaner…

Treepete, I’ll keep you posted if the fault returns…

Great Forum by the way… and thanks for responding so fast to my post this morning,

Will (thedutydoc)