Fuel problems

[Andrade]

Hi guys, im facing fuel problems on my pinto viva and i cant figure out whats wrong:

 

Problem - the engine starts, works only if i stay pumping the gas pedal, and if i either keep the pedal pressed or let it idle it turns off.

 

Fuel gets to the carb, no problem, so its not pump. I tought it was the carb, i bought a new one, and its still doing the exact same thing. Spraying fuel in the carb keeps the engine working on idle. Stop spraying and it turns off instantly.

 

So if fuel gets from the tank to the carb, the carb isnt faulty, what else can it be?

[Toby]

Sounds like pump jets are ok, but an issue with the idle circuit and the mains.

 

That's my take on it - I am no expert!

 

What carb is it - incase someone cleverer comes along (very likely!)

[Andrade]

Only theory i can come up with is that there is not enough vacum produced by the car to keep the petrol flowing. does this make sense?

[Andrade]

Sounds like pump jets are ok, but an issue with the idle circuit and the mains.

 

That's my take on it - I am no expert!

 

What carb is it - incase someone cleverer comes along (very likely!)

 

the carb is a Weber DMTL like this one

 

[Toby]

Yes I suppose it does - so leaky manifold somewhere?

 

Or pipe / screw missing somewhere?

[Andrade]

manifold is with a new gasket, i put the engine together very recently. I'l go to my mechanic and do a compression test tomorrow. if comression is low its definately a problem of that sort. maybe valves get stuck or not seating well or something like that. i soooooo dont feel like taking the engine apart again