I have a 1972 ford f100 with a 390 that turns over but will not start. The gas fills up the caberator with gas. Has spark you can pore gas directly into the carberator and it will burn that off right away. is it the vacum lines that could be the problem. Any help

 

Well, if it starts and runs for a little bit after you pour gas directly into the carb throat, that means you have spark and your ignition is working. If the fuel pump fills the carb with gas that means the fuel system is working, at least up to the carb. But if the carb overflows with gas delivered by the fuel pump, that means you have a carb problem. With the engine off, pull the air cleaner and look down in the carb throat...work the throttle linkage and see if you can see two squirts of gas while you work the throttle linkage. If so, the carb is delivering gas like it should. If not, the accelerator pump on the carb may be shot. If the carb is overflowing with gas as you try to start it, the float and/or needle and seat in the carb is not working. Either of these problems means you need to pull the carb and rebuild it...not hard to do and you can get the kit at any parts store for about $25 or less. You should have a vacuum line running from the distributor to a port on the carb. If you have power brakes, you should have a line running from the brake booster behind the master cylinder to the manifold vacuum tree...on the back, left of the manifold behind the carb. If you have an automatic transmission, you should have a vacuum line running from the tranny to the same vacuum tree. Just make sure all your vacuum lines are connected and the lines/hoses and connections are in good shape. Sounds like your carb is at fault, based on what you posted. Post back and let us know what you find.

 

i forgot to mention that i have already rebuilt the carb.

 

That's great but it doesn't tell me/us much. Is the accelerator pump working? Does it pour gas out the vent like the float/needle/seat isn't working? Are all your vacuum lines in place and good? Need more info to help you out here.

 

alright going to buy some new hoses. Also when i have the blinker on and use the brake the brake lights dont work at all or the other way around.

 

Haven't rebuilt the carburetor yet, just check the jets. It works fine at idle. When I'm driving, I accelerate hard, and the engine stutters. I release the accelerator a little and the gears return to normal after a few seconds. I think it could be the maximum acceleration pump, but I'll only know when I disassemble the carburetor. I thought it could be the engine timing, I adjusted it to 10 degrees, 12 degrees, and finally 6 again, but the misfires on hard acceleration continue. Spark plugs 0.45 gap. electronic distributor kit and new coil 12v. Any other tips besides the carburetor?

 

Certainly could be the carburetor. But I wouldn’t dig into it just yet.
You can find out if it’s the accelerator pump without disassembling it. As described earlier in this 14-year-old thread, pull the air cleaner off and push the throttle linkage to see if the accelerator pump is working.
To make sure it’s not ignition timing, connect a timing light and watch what happens to the timing as you rev the engine.
Also, check your PCV valve and make sure there are no vacuum leaks. Maybe not as likely, because you would notice a rough idle if there were.
But it’s still worth testing.

 

thank you!!!!