1999 blazer 2 door...fuel smell

Rick54

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4.3 engine ..automatic tracks......after running the car you can smell fuel......even sometimes while driving with windo open?....car is parked in same spot everytime on pavement showing no signs of fuel leak....under car there is no wet spots showing a leak or even where is may have leaked sometime?...gas cap is new..but check engine lite is on showing ...evap code?....sorry as I lost the info when they scanned it?..any ideas where to look..thanks
 

CHUCK06

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Look under the hood, does your oil smell really gassy, check the fuel rail at the top rear of the engine for leaks. have you noticed a drop in fuel economy since this started.
 

kev2

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do the obvious easy look around like chuck suggested,gasoline is so flamablenot to be cautious...tell us any drivabilty issues - hard start clouds of black smoke - - - also consider the FREE scans at auto parts stores.. there may be a pending or a code in history, write the code down and post someone can help pinpoint issue..
 

Rick54

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no leaks on fuel rail.....engine oil is full with no gas smell

truck starts great and runs perfect...no misses..lots of power.....no smoke from tail pipe ever.this truck has been in family since year old and never a problem

gas smell seems to be coming from rear? only after it sits for about ten minutes,have fill id full and never leaks ,,,but strangly the fuel smell gets worse at the tank get near empty

sadly we have no free scan places aroung here....everyone wants cash..lol
 

Gus

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Places like Autozone give free scans....

You can have a leak, so small, that it may just leave a small wet spot(not accumulate enough to drop down) and could evaporate while driving down the road(air flow across it will just about eliminate it), but it will smell like a huge leak....

Need to get this on a lift to narrow the smell down......13 year old vehicle can have a rusted fill pipe, leaking tank, leaking mechanical joint, etc.
 

Rick54

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hi...thanks for all the replies....sadly this is a one horsetown in canada and we have no autozones?....just Napa and another parts place,but niether will scan it for free.......I will take it in to our 80 and hour garage and get it scanned..lol

....its like if I go out and start it there is no smell even after 25 minutes of idleing?.....then all of a sudden you can smell gas and my nieighbour climbed under it trying to located a leak ,,but none was found....he pulled off the gas cap and said no pressure?....not sure wht that means ,,,but hopefully a scan will help..thanks to all
 

billr

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Since you are isolated out there, consider buying a scan-tool (not just code-reader); the price has come down on those a lot and you will probably need it again some day. What you are describing, an intermittent leak, is likely to be from a cracked line/fitting that opens up from engine movement while driving. I don't think a code is going to be set from that, it's going to take a lot of visual observation while wiggling stuff. That can be done with the engine off, just go "key-on" briefly first to run the fuel pump and bring up pressure. A fuel-pressure gauge can also be useful, as it would show a pressure drop when a leak was initiated (by wiggling), even if you don't notice the leak. That will help you narrow the search area...
 

kev2

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Billr that is a great idea- esp when confronted with paying just to read P codes... :Clap
 

Rick54

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when cash get better I will get a code reader....


.....anyways I have the code read and removed?.........it was code P0440... Small Evap Leak ....does this give me any idea as to where and what to look for?.....the gargage guy checked the gas cap(only a month or so old) and said seal looked good?
 

kev2

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was there an issue P0440 before the new gas cap?
Was the new cap to correct the issue ?
Inspect the Evap lines at engine - often a yellow cap is attached to the vac/purge lines.

next we are checking valves ie purge, tank pressure, vent.
 

billr

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Again, wait until you can afford a scan-tool that will show "live data". They don't cost much more than a "code reader". Also, there has been discussion about inexpensive devices that will let you link to a PC or smartphone to do much the same. Look in the "General Discussion" forum, I think.
 

Rick54

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Kev2..would this "purge valve" be near the gas tank?....reason I ask when I got it scanned the mech said something about a purge valve being crap in these truck?.........the gas cap was replaced as someone wanted mine and help themselfs to it

billr ..I dont think I will be able to wait to afford a scan tool as sadly a month ago I was diagnosed with cancer so I am just trying to fix the truck so my son can drive it or sell it as he sees the need,,,,,But thanks to all for the help......bless you all
 

tdark

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Check the vapor canister which is located on the drivers side rear behind the bumper end cap. Tom
 

Gus

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What he meant was the vent valve, not the purge valve.....I think it has been redesigned......but don't run out and by one.....have it smoke tested first.....it's the only way to test this system and find a leak...
 

kev2

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this sounds like a maybe- did the issue P0440 develop AFTER you replaced the cap?
Was it a OEM? not the first time an aftermarket part caused a problem.

As I mentioned the underhood YELLOW cap it ID's the vent lines and provides an attachment point for testing ie the smoke machine , also next to manifold mounted purge valve ( it is a 4.3L?) - a place to look for leaks, cracked unplugged hoses...

The vent valve is rear mounted on a crossmember- I am not to familiar with the 2door... lines from canister should lead you there,

To start check the new cap as a possibility
 

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