Gasoline smell briefly on startup?

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The past couple days when leaving work in my 2007 Civic (5x,xxx miles) I've noticed a brief wave of gasoline smell after starting the car. At first I noted it happening when I was backing out of my parking spot (parking slightly uphill if it matters) and thought maybe the smell was coming out of the exhaust and then coming into the car as I backed through the vapors. This morning though I investigated a little and now I'm not sure - it may be coming from engine bay and in through the HVAC vents.

I'm talking a distinct smell that lasts for maybe 5 seconds. I think it only happens on cold starts after the car sits for several hours (8+ hrs when I've noticed it so far).

The car's taken a few more cranks to start occasionally lately too, although that might be the battery getting weak. It doesn't even nearly correlate with the gas smell at any rate. I scanned for codes and nothing came up (and the CEL is not lit).

There is absolutely no gas smell other than the brief wave at startup. Time will tell if this is an intermittent problem or something that just started and will happen every time.

One final wrinkle is I happened to notice this the day after I transported some gas for some lawn equipment -- just 1 gallon sealed up nice and tight in a gas can. I don't see how and gas from that would cause smells only on cold start though...


At any rate I realize there's some random stuff up there but I'm not sure what could be related. Is it possible this is related to some normal/occasional function of the emissions system? What could cause this kind of thing only on cold startup?
 
just from the tail pipe when the catalytic converter is still cold, does it smell like paint thinners at all? i get it if i back out and the windows are open or vents are on through-circulate.
 
I think it's normal. My car does it too. It has something to do with the fuel not completely burning off because the cats aren't hot yet or the engine using more fuel to reach operating temps or something. Someone correct me if I'm wrong.
 
The computer sets it to full rich for a few seconds on a cold start,and varying degrees thereafter,I agree with crinkles, set it to recirculate on the A/C upon shutdown the night before, to reduce this effect.
 
I smell "gasoline" too.

I have a hole in my exhaust manifold. I think exhausts smell like gasoline before they go into the cat.
 
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I would check if your fuel filter is leaking, i think it is in the engine bay on your civic. It can also be your gas cap, fumes are fumes and will escape the smallest of holes.

As stated above the cold starts are always going to be more rich.
 
If you have an injector leaking down it will take longer to start as it clears the flood, and will reek of gas too.
 
Originally Posted By: eljefino
If you have an injector leaking down it will take longer to start as it clears the flood, and will reek of gas too.


Would that always be the case? More specifically, if a leaky injector were causing this then would it likely always take longer to start when the smell is present?
 
Originally Posted By: SERonBLAST
I would check if your fuel filter is leaking, i think it is in the engine bay on your civic. It can also be your gas cap, fumes are fumes and will escape the smallest of holes.

As stated above the cold starts are always going to be more rich.



Fuel filter is in the tank.
 
If it's from the tailpipe, the at is not hot yet, and the car is in rich mode.

Under the hood or under the car smells are not good, though.
Start it with you on the outside and someone else starting the car.
Determine where it is coming from, at least front or back.
This may take a few days and a few tries.
 
I sniffed around a bit this morning and now I think it's coming from the tailpipe again. Good to know it's probably not a problem if it's coming from that end. I'll keep checking it out though.
 
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