Elkriver
Member
I am having gasoline fumes bad at idle and highway speeds, any ideas what to check?
Is this a recent problem/change on a car that is familiar to you, or is the car new to you?I am having gasoline fumes bad at idle and highway speeds, any ideas what to check?
all that is ok no fuel in oil and no sign of leakage?First thing I would do is pull the oil dipstick and make sure it's not being contaminated with fuel.
Visual the entire fuel line for any sign of leakage.
Make sure the choke is working properly.
choke is working properlyFirst thing I would do is pull the oil dipstick and make sure it's not being contaminated with fuel.
Visual the entire fuel line for any sign of leakage.
Make sure the choke is working properly.
car is new to me but I just had the six pack carbs rebuilt and had the gas tank changed, I really never drove it before this changeIs this a recent problem/change on a car that is familiar to you, or is the car new to you?
I will check for openings into the cabin space .Tuning for sure
Also everything at the rear of the car , trunk seal , taillight seals , any open holes or rust in the rear 1/4 panels or trunk drops inside the 1/4s , you should not be smelling fumes at highway speed at all .
I will check this diagram out and see what I haveCheck to make sure the VENT tube has a tube on it that runs outside of the trunk compartment. It should vent down under the car to the frame rail.
A previous owner of my Challenger had removed that line at some point, for some unknown reason and I had really bad gas fumes inside the car until I finally figured out that the vent line was missing. Fumes were just vented inside the trunk from the gas fill pipe, smelled so bad that I could hardly stand to drive the car. Installed a vent tube going under the car to frame rail and problem solved.
This is for a 70 Challenger, a Cuda may be different, and then again maybe not.
View attachment 122698
I did check the fuel pump and it seems to be an after market with *8lbs and 80GPH rating but it has no unit downstream to relieve the excess fuel r pressure? that may be a problem??I will check this diagram out and see what I have
Just had the plugs and wires replaced again, less than 500 miles on last change, have a slight miss at idle but goes away on higher revs. I had the six pack carbs redone by a professional carb shop and they seem fine, I just want to be able to drive it without getting gassed to death. I had a 67SS chevelle that i did not drive enough and had a lifter stick on it and it would eventually free up after I drove it for while, the miss on the Cuda seems to mimic the same miss??, I am going to check the fuel lines for leaks at higher rpm's and see if I have something showing up and the vent line on the new tank, Thanks for the suggestions!Have you looked at the plugs?
Where is timing at?
How are your carb tuning skills?
You own a six pack carbureted musclecar. If you ever want it to live up to its potential, go buy a Holley book, a tuning kit, wideband O2 meter, and start watching some Youtube videos.
Just had the plugs and wires replaced again, less than 500 miles on last change, have a slight miss at idle but goes away on higher revs. I had the six pack carbs redone by a professional carb shop and they seem fine, I just want to be able to drive it without getting gassed to death. I had a 67SS chevelle that i did not drive enough and had a lifter stick on it and it would eventually free up after I drove it for while, the miss on the Cuda seems to mimic the same miss??, I am going to check the fuel lines for leaks at higher rpm's and see if I have something showing up and the vent line on the new tank, Thanks for the suggestions!
Check every hose, line, and connection for leaks. Then check your fuel pressure. Much more than 5# can cause eye burning richness and bleed over.I am having gasoline fumes bad at idle and highway speeds, any ideas what to check?
Yes the plugs do indicate it is running rich, as far as the timing goes,, it starts right up without any hesitation, and seems to be ok on acceleration, a little hesitation, but runs out ok, but not what I thought the 3 duece setup used to be like on older carbs setups?! Anyway, that is another problem all to itself. I will check the float levels again, check for fuel leaks at a higher rpm, check for proper venting and maybe put a regulator inline before the carbs? depending on what pressures I find tomorrow, I am going to go buy or rent a gasoline pressure gauge outfit and know for sure the pressures I am working with. more info later, Thanks for all the helpPersonally, I wouldn't hang my hat on the fact that a professional carb shop rebuilt your carbs, unless they also installed them on the car and then tuned it. If they didn't, then all they can provide is a general "out of the box" tuning setup that should at least allow the car to run. Since you can really F-up your car by running too lean, they probably err on the side of caution and have tuned the carbs to run slightly rich, just like Holley does from the factory. Just like any new out of the box carb, if you don't make the effort to tune it properly, you're leaving power on the table and will probably always smell like a gas station.
As far as plugs go, I wasn't suggesting that they are old. I'm asking if they look like the car is running too rich, which would point to a tuning issue as opposed to a fuel or exhaust leak into the car as others have suggested.
As far as timing goes, hopefully you are not just running it at the factory spec, which is like 5 degree BTDC for a 70 440-6 car. It's probably going to be happier with another 10 to 15 degrees of advance at idle, but that's a whole nother ball of wax to get into.
Good luck with it.
I have seen stock low performance fuel pumps put out over 12# of pressure. Check the line pressure at the carbs with a t and a fuel pressure gauge. Thanks for letting us know it's a 6 pack set up. (at least we think it is) If it hs Holleys, a backfire could cause a blown power valve and a rich running condition. Any old Mopar mechanics in your area? It sounds like you may be over your head. 6 Packs can be a turd to set up correctly and keep adjusted and in tune.I did check the fuel pump and it seems to be an after market with *8lbs and 80GPH rating but it has no unit downstream to relieve the excess fuel r pressure? that may be a problem??