gas fumes in cabin

If I park my van (66 e100 240ci) after the engine has gotten nice and hot and then return to it, say 15min - 45min later, there is the smell of gasoline fumes. It seems to be coming from the carb. Hot days are worse than cold days.

Previously I couldn't trace the source but then noticed the fuel pump leaking ever so slightly. So I tightened down the screws. Now the source of the smell is only on the carb side. The float valve appears to be working fine, though I'm not sure how high the fuel level is supposed to be in the carb (It's a DOPF-E carb, not the stock one).

My dogbox has lots of holes... just wondering if others have this problem. It is normal? Should I concentrate on sealing up my dogbox?

Also, does anyone know why the fuel pump for the thermactor engines is different than none thermactor engines? My van has a thermactor.

Donivan is correct. once again. I would still seal all of those holes so no carbon monoxide leaks into the van. No need to make yourself sick while driving. That happened to me once and I was sick as a dog. Sealed the holes the next day.

^^ The guys above nailed it.

I had a similar problem with mine, all of the gaskets and seals had rotted out of the dog house and let fumes into the cab. I stripped the whole thing and painted it and resealed it with new insulation and seals and it helps quite a bit.

Also, most older carbs will leak a little fuel around the carb butterfly shaft, especially when you turn the vehicle off in hot weather sealing the dog house helps with this.

In regards to "heat soak":
It's a big problem down here in the Deep South, summer temps run in the high 90's a lot of the time. Engine temps can spike high after you turn the vehicle off, it causes any fuel left in the carb bowl to vaporize (and sometimes boil). It gets forced into the intake manifold from the pressure and then you have a fuel rich (flooded) condition that reeks of fuel.

I'd like to mention that when I first got my van I had to replace the entire fuel system, tank, lines, carb, fuel pump. I put in an electric FP on a switch so in the summer time when it's hot I can turn the FP off when I'm stopping for awhile and I run the gas out of the carb (or mostly out). That really seems to help as far as heat soaking goes, obviously not something everyone would need (especially in Canada) bit in GA it really helps.

Wow... thanks guys. Everything you've said makes sense. I'll start by sealing up that dogbox.

I tried to see if there was fuel running into the carb when not running, but if I open the butterfly valve, all I see is smoke! Also, wouldn't opening the butterfly valve cause the accelerator pump to squirt in a bit of fuel? Still I didn't see any.

But, there is evidence that gas is seeping through the butterfly shaft in the form of stains... still never have seen liquid gas there.

I'm thinking about replacing the radiator fan with an electric one, that way I could set it up to run on a timer like Donivan has.

dakeddie,
J.C. Whitney has their insulation kit on sale currently, I used the same materials in a pre-cut kit that I purchased just for my A100. The material in this kit rocks, just make sure you seal all the edges with foil tape so fluids cant get behind it and turn the glue loose. Here's a link to the kit. You can get the same parts from Home Depot but I don't think they would be cheaper.

Here's what it looks like installed:

I tried to see if there was fuel running into the carb when not running, but if I open the butterfly valve, all I see is smoke! Also, wouldn't opening the butterfly valve cause the accelerator pump to squirt in a bit of fuel? Still I didn't see any.

It may just be fuel vapor from whats left in the intake and carb. The "smoke" is vaporized fuel, like you said, the accelerator pump gives a little squirt when you move it (if the carb bowl is full enough), it vaporized when it hit the intake manifold.

But, there is evidence that gas is seeping through the butterfly shaft in the form of stains... still never have seen liquid gas there

You'll probably see it after it gets to running temp and then you turn it off or if it's being hard to start and floods a little. You wont see it when its running as it will suck air into the carb past that shaft. Put your finger over it and you can probably feel it if its worn out enough, my old holley would actually whistle until it got warm enough to close the gap.

I'm thinking about replacing the radiator fan with an electric one, that way I could set it up to run on a timer like Donivan has.

I'm running a mechanical and a 16" Hayden electric (it gets really hot down here in the summer as I mentioned). I replaced my OEM fan with a Summit heavy duty fan (part num: SUM-G4920) and it works much better:


My electric fan is "16" Hayden Automotive PN: 3710", I only run it in the summer if I'm in heavy traffic as it draws a lot of power, about 16/18 amps, a smaller fan would draw less of course.
here it is installed:


Note that donivans electric fan is for moving air in the doghouse (I need to add one in my van like that as well!) the one I installed is just for extra cooling in the summer and doesn't help after the van is turned off (where donivans would help remove left over fumes)

Hey Donivan, I love that idea of the hamburger fan. How about some more info on that switch. Also, does your fan push or pull the air into or out of the motor box? I will be doing something like this. Great idea!!

Donivan, great idea on the timer! I've been wanting to add a fan also. Gotta' question (or two); I noticed two pics had different fans in them. Is there a difference in the two fans? Is one better than the other?

Thanks donivan. I was talking about the supplemental fan that you have attached to your anti-sway bar. My van runs plenty cool, even here in SETexas pulling our camper. I would like to add a supplemental fan like yours to help cool the dog house after a run.

Thanks for that info Donivan. That timer switch is a COOL idea and I see where you have it mounted under your dash. Thanks for sharing!!

This has been a great thread. I'm glad I started it!

Does anyone have a line on a autonatic timer to shut off the fan a few minutes after shut down? I want it to be fool proof as the wife and others may be driving van.

You made me look !! I found this ... http://www.lindelectronics.com/cgi-bin/store/shop.cgi/!ORDERID!/other/x/dbx_gen_port_acc/

Thanks Digz, I had found a couple, but these look to be ideal for what I want to do. The main advantage of these is tha adjustability and over discharge protection. I had found AMPERITE relays, but theyare special order and coustom built to your needs, Pricey and long delivery time. These will work just fine for what I had in mind.
Lester