Gas spews out of weber vents but only when car has been run up to operating temp and then shut off for 5 minutes. I get in to re-start it and when the fuel pump is turned on gas spews out of all 4 carbs. Fuel pressure is set at 3.5 lbs. If I tap them with a hammer they stop but some I have to tap more than others. What is causing this ? Why only when hot ? Seems like there is a build-up of pressure in the fuel tanks as well because when I undo the cap there is a pretty substantial hiss. I have yet to try and see if it happens with the tank caps opened before turning on the fuel pump. Any help is appreciated. I'm babysitting this car for a friend and it is a really great car by the way. I really like it a lot. A GT40 with AC. Whoddathunk !
Gas spews out of weber vents
- Thread starter John Woerheide
- Start date
I would do as you say and release the caps then see if it still does it.
Sounds like peculation, are the carbys isolated from the inlet manifold (1/4 isolators).
Or it could be as simple as it wants new needle and seats.
Jim
Sounds like peculation, are the carbys isolated from the inlet manifold (1/4 isolators).
Or it could be as simple as it wants new needle and seats.
Jim
Hi Johan,
It's a good idea to turn off the fuel pumps before you shut off the engine, even a block away from home (just don't run out in traffic). That way the carbs are not sitting full of hot fuel, nothing to percolate out and much less chance of a carb fire on hot restart. Do you have a heat shield around the carbs? Definately worth doing...
Cheers
It's a good idea to turn off the fuel pumps before you shut off the engine, even a block away from home (just don't run out in traffic). That way the carbs are not sitting full of hot fuel, nothing to percolate out and much less chance of a carb fire on hot restart. Do you have a heat shield around the carbs? Definately worth doing...
Cheers
Jack Houpe
GT40s Supporter
Don't forget the isolators that Jim talked about, they really work well for isolating heat transfer. The turkey pan and isolators should do the job.
Neal
Lifetime Supporter
Johan, did you ever resolve this issue? I was out this past weekend in 90 degree ambient conditions and when I shut off I saw a similar issue. I don't have a turkey pan or isolators and haven't seen this issue before. I popped the fillers and no excess pressure in the tank. Motor ran like a champ while I was out. The mystery of IDAs... :huh:
Ron Earp
Admin
Demon makes and economical, bullet proof, and great performing fix for this problem........
:wiseguy:
Ron, can you explain what you just said there please,
Ron Earp
Admin
Demon = 4 bbl carb.
Demon Carburetion - State of the art carburetors for the race and hot rod industry.
Meant to be funny but there is a serious side to the suggestion as well. Back to your regularly scheduled weber discussion.
A heat shield and turning the fuel pumps off a minute or so before shut off will help that problem.
Dave
Dave
It was a heat issue not a vent issue and the car came to me with no spacers, isolaters or turkey pan. I believe these items would have solved the problem, but I was in a rush to get to Road America so with the owner's blessing I put a 4 barrel on it and the problem is solved. Cutting the fuel pumps prior to shutting down the engine would have been a possible way to "get by" but as it ws a fire hazzard.......
Hi Johann,
Sorry we didn't meet up at Road America. What a facility! Next time... Yeah there's a special kind of adrenaline rush from seeing four little fires burning on the top of the Weber IDAs! I keep a fire extinguisher inside and one in the engine bay, doesn't have to be big, just quick to get to.
Besides shutting off the fuel pumps early it's a good idea to do hot restarts with the engine cover open. On a kick back you can get a nice gas cloud sitting in the rear window area. I've actually seen said cloud get sucked into the carbs on the next crank of the starter. At the time I thought it was cool, kinda like seeing a tornado the first time, could have gone the other way...
No doubt with the heat shield and isolators you'll be fine.
Cheers
Sorry we didn't meet up at Road America. What a facility! Next time... Yeah there's a special kind of adrenaline rush from seeing four little fires burning on the top of the Weber IDAs! I keep a fire extinguisher inside and one in the engine bay, doesn't have to be big, just quick to get to.
Besides shutting off the fuel pumps early it's a good idea to do hot restarts with the engine cover open. On a kick back you can get a nice gas cloud sitting in the rear window area. I've actually seen said cloud get sucked into the carbs on the next crank of the starter. At the time I thought it was cool, kinda like seeing a tornado the first time, could have gone the other way...
No doubt with the heat shield and isolators you'll be fine.
Cheers
Similar threads
