so i rebuilt my carb, 80 f150 302 stock motorcraft 2 barrel non feedback. has a brand new fuel pump and battery. truck still runs as it did before. need to give the carb a drink to get it started. and will stay running while on the throttle. theres only one inline filter up at the carb, (the one that doesnt screw in) check out ok when i blew through it. i dont have a pressure tester to see what the fuel pressure is at. i just had it running for a minute or two, went to let idle and died. it started back up without a drink, but died shortly after. any ideas short of pulling the lines and what not? theres only about 5-7 gallons in the tank at most. it was drained before is sat and didnt have gas in it until i went to get it. and i dont have belts on the smog pump or altenator, though i doubt thats the issue.

oh and there two vacuum lines i assume, coming from the carb to the pass side exhaust manifold that are metal lines that rusted and broke. one of them is the line that screw into the pass side of the carb near the rear. thanks for all the help in advance, i know ill get good responses as to figuring it out.

-Jerry

 

You need to get the alternator working. You are running everything off the battery. If the charge in the battery gets low enough, the truck won't run.

As for the fuel pump. You can take the fuel line off the carb, stick the end into a GLASS container and crank the engine. You should get good rhythmic flow. This will also let you see any debris that might be in the fuel.

Are you letting the engine warm up before you let it idle? It sounds like you might have more than one choke issue. Is the choke closing when it needs to? Is it opening up fully when it needs to? A malfunctioning choke can keep the engine from running and/or starting.

See next paragraph for the second issue.

Those are for the Choke. The choke on these carbs are electrically assisted thermostatic chokes. The tubes you speak of are the fresh air line going to the exaust manifold to be heated, and the return line with the heated air going to the choke so the choke opens. Without these in place the choke is not going to open correctly or satisfactory.


You may also have a air/fuel mixture ratio issue that needs adjusting.

 

i should have added, that battery is brand spanking new, just bought it this morning. the altenator belt was there but snapped after running it for a minute. first thing i did before i gave the carb a drink was i pulled the sending line off and put it into a clear plastic bottle and cranked it over. no gas at all.

 

With a mechanical pump, gas should steadily "squirt" out the "sending" line. If it doesn't you may have a blocked line, or a bad pump. It might take some cranking to get it to flow though, if there is a lot of air in the lines.

Check fuel filters for clogs etc...

There is a filter sock inside the gas tank, attached to the fuel gauge sending unit. It's possible that is plugged.

 

to avoid having the drop the tank (bolts on straps would break) or lifting the bed off, would opening the gas cap and blowing through with an air compressor from the carb blow what ever is on the sock off? i was going to do this anyways to make sure the line itself wasnt clogged, but i wouldnt want to hurt the sending unit or anything in the tank cause then ill have to get inside of it anyways.

and for the vacuum lines for the choke im going to pick up a choke stove kit and see if i can get the old connectors out of the nice rusty manifold.

 

I'd do that from the fuel pump feed line back toward the tank. But yes that should remove and blow that filter sock completely off. The only thing is you will need to add a filter before the fuel pump to protect it from the larger particles that the sock was blocking.

Blowing through from the carb through the Fuel pump could damage the pump.

It shouldn't hurt anything with the gas cap removed. You should hear bubbling from the filler. Just don't put excessive amounts of pressure through the line or it could blow etc.. Just enough to blow the sock off. 50psi would be way too much etc. If 5-10psi hurts anything etc... then it was time to drop the tank anyway, or replace the part.

You can cut them flush, then drill them out to the required size if needed. Then clean the filings with a shop vacuum, or compressed air. The holes in the manifold do not reach the exaust chambers. Its just a passage that goes through the manifold, that's open on either end.

 

thanks alot for all the help. ill let you know how it turns out. since i have to get manifold gaskets cause i have to drill them out, i might as well spend the $12 for the choke stove kit and replace the lines too. thanks again and ill give an update.

 

I'm having the same problem with the vacuum line that comes out of the exhaust manifold and runs up to the carb. The metal pipe that comes out of the exhaust manifold rusted off which left me with the bolt head on the bottom side of the exhaust manifold that I somehow must get the vacuum line hooked to. I'm at a loss, I have tried to remove that bolt but it is pretty corroded. Any advice anyone??