Hello,
I have been replacing the intake manifold due to a coolant leak in the center port. The car before this would start great and run (idle) really good for a few minutes then start to stumble. I thought it was the intake manifold coolant leak causing this but today when I went to burp the coolant system I noticed it did the same thing, idle great for a few minutes then stumble. It clears up when you press the throttle but stumbles on idle. So while leaning over the engine i noticed something i hadn't before, fuel was being feed to the secondary "chamber" with the secondary butterfly closed and i mean a lot. I turned the engine off and it continued to feed fuel for a minute or so. What the @#@$$? I guess this has been my problem from the beginning just never noticed it or assumed a brand new Redline Weber 32/36 DFEV would mess up. Oh I did check the float level when I bought it. I might re-investigate that. At this point would the fuel pressure be to high, I here Webers are finicky, but again it is a brand new mechanical fuel pump.
Any thoughts or suggestions. What should I look for when I open it up?
weber pumping fuel into the secondary at idle
-
70spider
- Posts: 676
- Joined: Fri Mar 14, 2014 3:05 pm
- Your car is a: 1970 Fiat spider
- Location: N.E. New Mexico
weber pumping fuel into the secondary at idle
1970 Fiat Spider 124 Sport aka "Pesto"
2002 Mazda Protege5
2013 Buddy 170i
2002 Mazda Protege5
2013 Buddy 170i
-
18Fiatsandcounting
- Posts: 3798
- Joined: Fri Mar 15, 2019 11:23 pm
- Your car is a: 1969 and 1971 124 spiders
- Location: San Francisco Bay Area
Re: weber pumping fuel into the secondary at idle
I thought about this. My guess is that it's one of two things: 1) the float level is too high, or 2) there is no vent on the float bowl. Redline probably sets the float level on the DFEVs to what their main customers need, which are likely VW Bug owners (not Fiats).
On the 2nd possibility, I have heard that some DFEVs don't have a float bowl vent, although both of mine (authentic Weber and an aftermarket) do have an opening from the float bowl up into the air cleaner area. But, if by chance you don't have a vent, pressure could build up in the float bowl due to engine heat, which would force fuel up into the opening into the barrel.
The other thing that might be going on is that you are at pretty high altitude. Fuel tends to boil easily at higher temperature on hot days, so if the engine is very hot, you might simply be boiling off the fuel in the bowl. Try a different grade of gas, or perhaps set the float so that the gas level in the carb isn't as high.
-Bryan
On the 2nd possibility, I have heard that some DFEVs don't have a float bowl vent, although both of mine (authentic Weber and an aftermarket) do have an opening from the float bowl up into the air cleaner area. But, if by chance you don't have a vent, pressure could build up in the float bowl due to engine heat, which would force fuel up into the opening into the barrel.
The other thing that might be going on is that you are at pretty high altitude. Fuel tends to boil easily at higher temperature on hot days, so if the engine is very hot, you might simply be boiling off the fuel in the bowl. Try a different grade of gas, or perhaps set the float so that the gas level in the carb isn't as high.
-Bryan