Hello Everybody I have a 79 Bronco 351m/c6 auto trans..

The Truck runs and fires right up but it has a rough inconsistent idle and it drives great until you stop for a bit ( to get the mail or get fuel ) it takes off great but then appox. 30 seconds later she tries to stall and stammer until you slap it in neutral and feather her out and then it keeps on moving..

it has the Motorcraft 2150 2bbl.. I thought it was the accelerator pump diagram leaking so I picked up a kit, replaced it and power valve while i was at it and it ran great but still having the same issues.. So I started playing with the vacuum and when I disconnect the PCV valve and plug the hose that goes into the intake it smooths out.. I tried another PCV and it was a little better but still having issues.. Also this carb has no back port for the pcv so I'm using one up front under the carb on the intake.. the brake booster line and everything else is on the tree at the back of the intake.. only vacuum advance is on the carb.. rest are capped

Now I have removed the smog pump and all of the lines and capped off everything i can find.. however The EGR valve is still on the intake manifold.. Its not mounted on the carb like some.. could that thing be leaking and need to be removed and capped off with a plate? could it be causing a vacuum leak?

I really need a vacuum tester and a timing light..

What else should I check for ?.. i've been at it for days now.. Thanks everybody I'm new to the forum btw

 

Just to let somebody who might need input in the future know..

I had excessive water in the fuel... So I took an electric fuel pump and hooked it up to the fuel line going into the tank and a battery and sucked the tank dry and separated the water and added a fuel additive and replaced filters it runs great!

 

Nice find. Thanks for the feedback.

 

No EGR valve on any FoMoCo vehicle mounts to the carburetor.

EGR valve bolts to the EGR/Carb spacer plate, located between the carb and intake manifold.