vacuum leak

[mik]

what would be the best sequence of tests to run to find if there is a vacuum leak? My fiat is a 1969 124as, 1438cc. With throttle pushed in all the way, the engine dies. Thanks for the help.

[azruss]

not much info to go on. tell us how the car runs at idle, light trottle. what rpm does it idle at, etc. does it drive down the road without surging? Usually vaccuum leaks create problems in all these areas. If none of that is happening and the only issue is full throttle, i would look at the fuel pump.

[mik]

When car is started and after warming, I push in the throttle and car will eventually idle at around 1000 rpm, when I push the throttle in all the way, engine dies. I don't notice any surging while driving. Acceleration seems fine, doesn't stall or hesitate at all. It seems like I have to have the throttle out somewhat to keep it running. The car hasn't been alive for a number of years. Put in new battery and it turned over fine. It does take a little coaxing to start, however I am in a cold climate. Car is garaged.

[mdrburchette]

The more throttle, the less vacuum. I don't know if you're old enough to remember vacuum operated windshield wipers, but my 66 Rambler had them and I'd have to drive fast in the rain then coast so my wipers would work. I hated that car.
I would not rule out a worn out fuel pump diaphragm. If you had a vacuum leak, your car would idle okay, but driving moderately or lower rpms, it would act like a plug wire came off and it would pop through the carb.
If it's a fuel problem, watch your tach. It will keep showing engine rotation speed but the car won't go when you push on the gas. Since the car hasn't been driven much, I'd also change the fuel filter and see if the gas coming from the tank is free of debris.

[So Cal Mark]

since the car has been sitting, my bet is the idle circuit is plugged with varnish