Raw fuel smell in the car.

[dave's not here]

Greetings! 1968 four door plym satellite. Did the car originally come with a vented gas cap? Has non vent on now. Sure could use a few ideas on where to start the
checklist of probably causes. not seeing gas anywhere - not running way rich...notice mostly after speed changes (slosh?).

Thanks as always!

 

[Lefty71]

A lot of gas tanks rot the top half or the seams, not the bottom where the fuel always sits.... You could try filling it all the way up, but be prepared to deal with the consequences and get the fuel back out if need be.... Could be just the filler grommet too...

 

[WileERobby]

Is it a federal or California car ?

 

[diesel_lv]

I've got a new tank, all new filler and equalization hoses. New PTFE lines and factory 3/8 steel lines w -6an fittings, new gas cap on fuel injection on my '67 Coronet. I still get a raw fuel smell very strongly "inside" car when I decelerate from a long steady highway drive. 2 yrs n can't figure it out. Good luck.

 

[Darter6]

I had that going on with my 67 Dart.It did have a vented cap. My problem was strong odor when driving. Stop and check things, nothing. Drove me nuts during a cross country trip. Once I got to my destination I left the engine running and found the crimp on the fuel pump seeping. Turn the engine off and the fuel would evaporate so fast It was gone before I opened the hood.

 

[Lefty71]

Is it a federal or California car ?

I don't want to take the OP's question off-track, but I'm wondering....just when did California Emissions Standards start to come into play in the world of Mopar??

 

[Don Frelier]

If it's after speed changes then check the filler tube and the fuel gauge sending unit connections.

 

[WileERobby]

I don't want to take the OP's question off-track, but I'm wondering....just when did California Emissions Standards start to come into play in the world of Mopar??

Late 60's, not sure exactly what year, maybe 66 ? , since I was on the east coast, but it applied at all CA cars.

 

[WileERobby]

I've got a new tank, all new filler and equalization hoses. New PTFE lines and factory 3/8 steel lines w -6an fittings, new gas cap on fuel injection on my '67 Coronet. I still get a raw fuel smell very strongly "inside" car when I decelerate from a long steady highway drive. 2 yrs n can't figure it out. Good luck.

On rare occasions, If a vehicle is not sealed adequately in the rear, exhaust fumes can enter into low pressure areas in the back of the car, if the mixture is on the rich side it can have the same effect.

 

[cosgig]

My Roadrunner sometimes leaks gas out of the top of the float bowl on the center carb. The intake is sometimes wet right below that. There is a rubber disc that covers the float bowl vent, I assume my smell is coming from there. It’s a 6bbl car tho, your carb may be different.

 

[Sixpactogo]

I had the same issue as Darter6 in post 5. I seemed to always have a gas odor while driving my Sport Fury Convert. I too thought it was a venting issue but turned out to be the fuel line at the fuel pump. Just like Darter6, by the time I opened the hood there was no leak to be found. It would only leak when the RPMs were were above 1500 or so. I only found it by accident while adjusting the timing. Good luck figuring it out.

 

[dave's not here]

REVISITING .finally! I've narrowed the problem down. shaking the car up and down produced no aromas, there is no aroma of raw fuel once youre into the secondaries. there seems to be a just-off-idle bog (13-1500 rpm) . SO:
A: low the fuel pump down to maybe 4.0 psi instead of the 5 it's at? B: AVS2 primary jet reduction? C: AVS2 primary nozzle reduction? onward!

daver

 

[NoCar2023]

Fuel sending unit seal leaking?

 

[dave's not here]

Fuel sending unit seal leaking?

ah. ok. if so - why only under such specific conditions?

 

[NoCar2023]

"Raw fuel smell in the car."​

A "Raw fuel" smell inside the car is typically a fuel or fuel EVAP leak, not an off-idle air/fuel mixture issue.

I have experienced fuel-sending units leaking and causing a "raw fuel" smell inside the car.

 

[1 Wild R/T]

Late 60's, not sure exactly what year, maybe 66 ? , since I was on the east coast, but it applied at all CA cars.

Depends on what you want to call emissions... PCV in 1963, closed crankcase 1967..... Evaporative emissions? 1970... NOX? Initially in 70 with retarded ignition & cam timing but the EGR first showed up in 72

 

[dave's not here]

will start with sender. that does make sense

 

[Cartel]

my 66 has 2 tank breather tubes and 1 is in the trunk...I smell it

 

[retractable]

I had a uel pump leak like post#5
New pump but it was leaking at the crimp on the two half. I fixed that and gas smell was gone while driving