gas smell at start up

over this last year I have been smell some unburned gas smell at start up. in the mornings and late after noons leaving work. Thing morning in in Socal it was about 65 out and started my truck walked around to load some thing. The smell was bad also my the trucks MPG is down over the last year. no power loss as of yet. Never smelled of gas, just had the cold motor smell most of the time. dose not have a bad smell on worm starts. No codes at the dealer.

any Idas? bad Cats, bad injector?


truck info-- new off the lot 2008 dc lb trd 76k, mid grade in town. 91 when I tow. moble1& trd filter at 5k and up. fuel injector cleaning every 36k at dealer.

I have 2 stroke bikes and 4 stroke bikes that have smiler smelling starts.

 

GET OUT!!! ITS GONNA BLOW!!!

 

Sorry for that.

So it is just upon start up? Does it go away after running and/or you are driving?

 

ya it clears up after about 1 min of run time. I just went to lunch no smell but the temp was just at the cold line.

I have always been a believer in worming up a motor. I never drive off till the temp hits the cold line or just above. The Truck never uses a drop of oil so it is not blow bye.

 

leaking fuel injector. leaking at tank fittings. damaged tank. damaged fuel lines. malfunctioning evap return

 

I do use the chevron tecron truck stuff in the big bottle about every 5/10. On top of the dealer using the stuff that is put in the fuel rail to clean. Dealer turns off the fuel pump and hooks up a line to the fuel rail. then starts the truck with this can of high presser gas. looks like a fuel can for a camping stove.

I had the hookups for my s-10 to do it my self but did not fit this truck.

 

alot of people may not agree or know it, but spark plugs can cause this. I only know b/c it happened to my tacoma. When was the last time u changed the spark plugs? alot of time if one of them has backed out, u will get a gas smell come thru the vents, especially at idle when the fan and/or ac is on. This will also cause ur mpg's to SUCK..

if i were u i'd check and possibly change the plugs and def. torque them to spec

 

spark plugs have been changed on time. only smells out the tail pipe.

 

Might try not letting it warm up so long. Only a few seconds is all that's needed...just take it easy driving for the first couple minutes.

 

What is your opinion on fuel injector cleaners? I always thought that they were bad for them?

 

I like using the Lucas fuel injector cleaner.

 

Mine smells like gas at startup, also. I never thought anything of it.you guys got mine worried now.

 

we will see what happens as time goes on. I'm hopping it is nothing big. My S-10 need fuel injections at 90K and a cat at 110K. I would hate to have to relive that. GM end up paying for the fuel injections under a CA-smog 100k recall. If the cats go bad I think I'm covered to 80k

 

Could be an o2 sensor going bad maybe...sometimes they wont throw a code even if they are bad..and ur mpgs would suck to

 

oh and x2 on the lucas fuel injector cleaner...i throw some in about every 3 months or so..(piece of mind)

 

Sooo. This is a really old thread. I just changed my spark plugs and my air filter to a k&n knock off. Could either of those cause gas smell at start up? Just noticed today. Changed them last Saturday. Could the spark plugs not be tight enough?

 

High flow filter may change the air fuel ratio a bit. One thing you don’t want to go cheap on is an air filter. Stock filters are really good quality. Oil charged filters are known to cause some issues with the mass air flow sensor. Did you happen the spark plugs? The pre gapped plugs are usually a little out of whack.

 

It’s an upgr8 dry filter, mimicks the k&n without the oil. Is there something I need to do to offset the air fuel ratio? I put in NGK pre-gapped spark plugs $9 a piece. I had my neighbor mechanic put them in. He said they were fine. We didn’t check the gap.

 

You can try disconnecting the battery to reset. I was at Toyota today to pick up spark plugs, and they told me that Denso will have the least issues. Apparently Toyota engines are picky about their plugs. About the pre gap, definitely a good idea to check them before installing. It’s common for them to be off.

The Densos are cheap too, less than $5 a piece.