Weber help?

[cruiksdr]

I've got my new set-up (3.0SC w/webbers) pretty well dialed in and am very happy with the performance. With a nearly 1 to 10 weight : power ratio, the car is quick and faster than stink

I am having an odd little problem though. Periodically, one of my float valves gets stuck cutting off the fuel to at least one of my cylinders. I know this is happening because when I uncorked the float level plug once there was no fuel in the bowl. So now, the car will be running just fine, and then it'll get a bit rough and lose power, and then later be fine again. I imagine that the valve is sticking intermittently.

Any thoughts about how to fix this or do I need to just replace the check valve??

Thanks!

[OZCarrera3]

The only 'help' we can give Webber is to get rid of that "boat-anchor" BMW engine!

[911pcars]

First, I'd make sure the float isn't hanging up on the side of the float chamber and the pivot pin isn't bent.

Anything else blocking the fuel inlet? Existing Weber screen filter still there?

Next, I'd try Grose Jets, a ball-type inlet valve that replaces the needle and seat type valve. I'm pretty sure they still sell them. Supposedly, they have better (more positive) shut off characteristics. Although you have more than enough positive shut off, maybe these would help.

Hope this helps,
Sherwood

[Steve@Rennsport]

Sherwood:

Grose jets in a 914/6 is a huge no-no,.... They are fine for a 911 but they cause big-time flooding in a mid-engined car. This has been the situation since 1977 with these things.

Daniel needs to go through the carbs and check the floats, pivot pins, and perhaps replace the needles and seats with new Weber ones.

[Allenk]

Do the webers have the float height access bolts on the side of the bowls. I read posts with people checking float heights and when reinserting these in their zeniths they do so too far and the floats rub them.-Just a thought.

[RoninLB]

Originally posted by cruiksdr

So now, the car will be running just fine, and then it'll get a bit rough and lose power, and then later be fine again.

afaik
If the fuel is completely shut the combustion will obviously shut down. If it's leaking some fuel it may be causing detonation from a lean mix. The detonation will cause your EGT to rise a little or alot.. If you limp along while the denotation is happening it may stay only a hundred deg or less hotter than the others. If you ride it hard the denotation will skyrocket and god bless your exhaust valves.

[911pcars]

"Grose jets in a 914/6 is a huge no-no,.... They are fine for a 911 but they cause big-time flooding in a mid-engined car."

Steve,
Could you explain this phenomenon on the 914-6? Vibration? I think our engines hang out further from the rear end.

Thanks,
Sherwood

[dvkk]

I'd replace it with an original Weber inlet valve.

In the VW world, Grose jets are known to be great on the track since they can hold back 6-7psi, but on the street they don't control the fuel level as precisely as a Weber valve.
The whole argument could be moot since Mr Grose doesn't appear to make them anymore.

[randywebb]

Grose = big