# Weber carb nightmare



## Bluemm (Apr 26, 2007)

I just installed a brand new weber progressive 32/36 DFEV kit on my 75 Porsche 914 1.8 I am using a 2-4psi fuel pump. When I started the engine for the first time it ran rough, but ran. I then had gas spraying out of the top of the carb. I installed an adjustable fuel pressure regulator and set it at 1.5psi. I started the engine again and the engine raced up and down for a minute then faded out and died. No gas sprayed from the carb this time. I started the engine again, and the gas was spraying from the carb again. Could I have damaged the float from the high fuel pressure? 
I have the vacuum port plugged for now, but the plug keeps blowing off. What would cause this?


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## qldit (Mar 26, 2007)

Good Morning Bluemm, your problem sounds like a real problem in that carb.

Normally a fuel pump can deliver in the order of 4 psi without problem, and naturally was prone to cause fluctuations in the fuel level in the carb as the float valve modulated it's fuel level, so having a pressure relief valve (usually routed back to the tank) helped to remove those supply surges and helped maintain a constant level.

I usually look at least 2 PSI for the supply, is that 1.5 PSI valve recommended?
It is getting a bit on the low side from my point of view.

Normally with most carbs the reservior fill level will be in the order of between a quarter inch and three eighths below the top.

It sounds like your float valve is not operating correctly, or the float is impeded somehow causing flooding.

This needs investigation.

Your mention of the vacuum cap "popping off" is very strange, it is almost as though you have a misfiring effect allowing a positive pressure to happen in the intake manifold.

Is this engine in prefect condition?

Having that marginal increase in fuel pressure should not affect the carb adversely, so there should be no damage expectation.

Cheers, qldit.


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