I am getting fumes in the car at times. Not all the time, and not the same smell. Some times it smells like exhaust, other time it smells like gasoline.

When installing my new interior I use a sound deadening blanket and spray foam to try and seal every hole. I have checked every inch of fuel line and no leaks. Also my entire exhaust is all new and clamped tight.

Any ideas?

My exhaust exits out the center of the car, not the side. Could this be a problem? Maybe getting fumes sucked into the boot, then into the interior?

Also I still have some very small holes in the fire wall i need to fill, around wiring where it goes through the firewall.

 

You could try to check that the joints on the exhaust are airtight by brushing soapy water onto the joints, the same way you check for leaks on a gas grill. If you see bubbles, then you have a leak.

For the gas smell, is there any consistency like when you have just fueled up or are running low on fuel?

The other thing is to make sure you didn't cover up any air outlets in the rear of the car when installing the sound deadening. Many people don't realize it, but most cars (all?) have air vents in the rear of the car to let air our of the back of the car. I think they are open all the time, unlike other vents which are controlled by the climate control system. One of the main purposes of these vents is to avoid the problem you are experiencing and protect the cabin from carbon monoxide intrusion.

Good luck!

 

No consistency on the gas smell. Where are the exit vents in the back of the car?
I'll check on the exhaust like you suggest.
Thanks for the help.

 

My '75 has a vented gas tank with a plastic line that allows pressure/vapor to escape. If you have the same type of setup, check to see that the line is still attached to the tank and not cracked or something.

 

I don't know where the vents are in these cars as I've only had my MINI for about a month. I'm sure someone on this board knows, and even better may have pics. Anyone?

 

My gas tank is a 12 gallon racing cell I got from Jegs. It has one line out to the pump, one in return from the injectors, and a vented cap.
I've looked allover around it and can't find any wet spots any where.

 

When I changed my exhaust from the corner, to center I started getting fumes inside, then I noticed the rubber boot seal had a one inch gap at the bottom center and the lid was stained, I closed up the gap and the fumes stopped, I also have foam rubber shoved in the gaps between the body and the sides of the rear seat.

 

Thanks for the help. I have tried to plug all the holes in the back wall but do have a lousy boot fit. I'll have to work on that.

 

My gas tank is a 12 gallon racing cell I got from Jegs. It has one line out to the pump, one in return from the injectors


and you ask for help from "regular classic owners" because . . . .

 

Perhaps the vented cap is your issue. I believe the factory fuel tanks vented out the caps as well, although the difference there is the cap is externally mounted on a factory setup. Is it possible to get a non-vented cap to see if the fume problem goes away? If it does it means that either you have to route the fuel cell filler to the stock fuel fill location or seal the boot-to-cabin firewall to keep the fumes out. I'm assuming you did make a firewall. I know NASA requires a firewall if the stock fuel system is no longer in place ... I'm assuming SCCA requires the same.

I would ask this question in the Vintage Mini race forum and see if they have seen similar issues with fuel cells.

Good luck,
Jeff

 

Pretty well known in classic mini circles that Center Exit Exhaust = Fumes in Car

Aerodynamics ar such that there is a swirl behind the car that pushes the fumes back to the boot lid. If you're rear windows are open, your boot lid seal is compromised, or even if there's no obvious openings at all, you will get fumes in the car.

Side exit (standard location) pushes the exhaust into the laminar air flow and carries it away.

 

well we have two half answers - one for gas and one for exhaust but nothing that covers both bases which comprises OP's question.

However wrt the fumes and boot question, your logic is good, however I have a big twin DTM centre exhaust

and I don't get any exhaust smell (or I'm always drowsey from the fumes) even with the rear windows open. Maybe I'm going too fast for them to catch up, but I doubt it.

But IF you suspect a poor boot lid seal consider removing the seal that attaches to the boot lid and using the newer boot seal that attaches to the lip of the boot opening; that is IF you have the older type (pre 1988)

When I rebuilt my boot lid - which is a MK1 lid btw - I tried several times to get that darn seal to attach properly, but all those little clips and the bends it makes - argh - after three tries (that's sets of clips and lengths of rubber) I tossed everything in the trash, sealed the holes for the clips and used the newer seal. It took 2 minutes to fit it and it seals better; better than a poor condition or poorly fitting original anyway.

http://www.minimania.com/web/item/CK.../InvDetail.cfm



part description says glue it on, but like a door seal I just pressed it over the lip of the opening and it works perfectly, and hasn't moved a mm since I put it in place. The lip being the knife edge that normally meets the boot mounted rubber.

Now, is the gas smell actually exhaust from a WAY TOO RICH engine . . .

You could perform an experiment and get some 2 inch wide masking tape and close every potential gap around the boot and both rear windows and go for a nice long drive. Still get the smell? When I had a whistle at speeds over 50 following a windsheild replacement this method of debugging helped me pinpoint the source of the whistle after the glass company had redone the job a second time but the problem persisted. They did the job a third time and that time knew where they were making a boo-boo.