fuel smell after acceleration

vikman78 · 07-17-2005, 07:53 PM

I have a 98 4WD 2Dr Blazer and have noticed a strong gas smell after accelerating from a stop. the smell seems to be comming from the engine compartment. I bought the Blazer this spring and put on a new intake gasket kit to stop coolant from leaking. After and during that operation i didn't notice anything unusual. I then installed an aluminum cold air intake tube. i have thought that this might be the culprit but the intake tube has been on for about 2 months and i didn't notice the fuel smell until about 3 weeks ago. I have read posts relating to this, so i have some ideas of where to start but would like some advice. the service engine light is not on and i have no performance issues. Is it possible that it could be a return line leaking and would this trigger a code?? Any help would be appreciated. I have learned alot from the posts and i am glad that such a site exists.
Thanks

BlazerLT · 07-17-2005, 10:13 PM

How do you fill your fuel tank?

Do you fill it right up to the top of the neck?

vikman78 · 07-17-2005, 11:36 PM

I have read your suggestion on that and there was a period of 2 weeks that we did top it off but not to an extreme. We were on vacation and basically just rounded to the next dollar. The smell was there before that and has continued since. I have been back home for 2-3 weeks now and have tried filling it less than a full tank for a while and the smell seems stronger when on less than half a tank. I understand about the charcoal box and how all of that works but if that was the problem wouldn't that go away?? And at 60mph how would you smell that in the front of the truck. It seems more like the smll is comming through the vents. Any other ideas???

BlazerLT · 07-18-2005, 12:31 AM

Vent line could have come off.

Take it to a shop and have them check it out.

Don't allow it to keep going like this.

vikman78 · 07-19-2005, 06:28 PM

I would prefer not to send it into the shop. I have done all the work on every vehicle i own. I really thought that someone might have an idea of what it could be or where to start. The smell is stronger on warm days than when it cools off for a while. It has been about 90 or so here for the past few weeks but on cooler nights the smell is not noticible. Does the evap line run in an accessible spot? and is it a rubber hose all of the way to the engine from the tank?

wolfox · 07-19-2005, 06:37 PM

Another possibility is that the seal around the locking collar for the sender/fuel pump assembly has rotten through. THey dry out with age and then turn into dust. It could cuse the smell of gaoline you are getting on warm days. This is a bitch to do though, the tank should be near to empty as possible to make handling it easier. It will have to be removed to check/replace the gasket on the upper part of the tank.

vikman78 · 07-20-2005, 03:42 AM

I spent some time tonight trying to locate but with no luck. There is no smell of gas outside of the truck it all seems to come through the dash vents. is it possible that the cold air intake could be causing the fuel mixture to be too rich and would this trigger a check engine code? I know that the light comes on, been through that with the gas cap. I can accelerate to 80mph and once i let off the smell is there. would the smell travel from the sending unit to the drivers seat at 80mph. will see what i can find and keep posting, Thanks for the replies.

muzzy1maniac · 07-20-2005, 05:00 AM

You're check engine light comes on? Take it to AutoBone and have the codes scaned. That should always be your first step. Otherwise you're just wasting time blindly "repairing" things.

vikman78 · 07-20-2005, 04:33 PM

The check engine light is not on, the problem may be easier to locate if it was and if it was a leak in a pressurized fuel system i thought that it should trigger a code. No problems with codes at this time though. Thanks

wolfox · 07-20-2005, 09:27 PM

Next step I would consider since it just takes 10 minutes to do:

You claim that there is the smell odor of gas in the cabin through the vents, and that it happens after acelleration. I am not certain if the 98 has an IMTV (someone will correct me, I am sure - they stopped making the split plenums in '99, right?) But if there is a Vortec plastc cover on top of the engine; use a #30 Torx bit to remove it. Under it, there may be a round plastic part that is held in place with a pair of #15 Torx fasteners. Remove that round plastic part, pulling it straight out, noting it's alignment so you can replace it later. Get out our penlight and get a look inside for pools of gas or a strong odor of gas. If the truck sat overnight, turn the key to the on position but do not start the truck. Leave it there at least a few seconds, then turn it off, taking the key out and get a look in the hole again for an odor of gas. There may be an oddball chance that your SMFI, one of the tubes from an injector may have rubbed/rotted through and is letting a spray of gasoline run loose inside. Just another idea to toss out there to help you chase your problem.

Hell, just poking your nose a few minutes after you have "primed" the pump near the inlet of your intake would give you a clue. I had a buddy that had a leaking regulator in an older CPI engine that would make a rancid, raw gas smell when it sat. It would leak down in the plenum, cook off the top of the engine and the vapors could be smelled right at the air filter box.

vikman78 · 08-20-2005, 06:40 PM

The fuel smell magically stopped, could have been from overfilling the gas tank. Our check engine light would come on with a p0446 code and we replaced the gas cap and that has stopped for now. Thanks for all of the replies and i am relieved to have this fixed.

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