We've been trying to get my brother's truck going forever. It was parked for a while (6 years). We got it to run and drive, but it ran rough and hesitated on acceleration. We came back in a week to work on it, and it would start, the idle would climb, then the engine would die. With very tricky feathering, we could keep it running sometimes, but it wouldn't stay running on it's own. It still hesitated when given gas, and then would die. We decided to rebuild the carb. I followed the instruction, and it seemed as though I did it right. We reinstalled it, and started the truck up, and it ran! It ran for about 15-20 seconds, then gas started spewing from the two stacks on the top! We shut down the engine. Every time we tried to start again, it wouldn't. We took the top off the bowl and adjusted the float, but it didn't help. Still no start, and the gas would start spewing from the stacks.

The only idea I have is that maybe the fuel pump is pushing too hard. What would make that happen?

Or perhaps a low manifold pressure not operating the power valve?

Any ideas?

 

I think it's possible that all the crud that accumulated in the lines between the carb and the gas tank are now between the needle and the seat.
When the carb was off, did you crank it to clear out the lines?

 

Yep. I made sure the carb cleaner would spray through each little port or jet. The crud that was in the fuel lines and gas tank gave us hell. We drained the tank twice. I filled the bowl on the carb with fresh gas one of the times we tried to start it. It didn't help, same result, no start, gas out of the stacks.

 

If its popping back through the carb, it sounds to me like the distributor is in the wrong place. Have you had the distributor out? Are your plug wires hooked up with the correct firing order?

 

It's not actually coming from the air horn, it's coming out of the two vent stacks in front of the horn, over the bowl. We haven't moved the distributor, and we have double checked the plug wires. I think it's either the fuel pump pushing too hard, or the needle on the float not properly seating (though it looked fine during my visual inspection). Keep the ideas coming though. Thanks!

 

Well I got the gas to stop coming out the stacks, the float wasn't right. We're still having issues, so I'm going to call a friend to come check it out. I'll repost when we figure it out.

The carb does still appear to be flooding the engine. I suspect low manifold pressure not operating the power valve. Is that a likely cause?

 

Uh..no. Why do you have low vacuum?
If its flooding at idle, you need to adjust the two idle air/fuel mixture screws. If it is a holley, tighten them up and back em out 1 1/2 turns. Tune it from there.

 

It's a motorcraft 2150. I suspect some overlooked issue for low manifold pressure. My brother's truck has been nothing but trouble since he bought it. Not a lot of money to fix it, but loads of time and annoying problems. We do currently have the mixture screws set at 1 1/2 turns. We're going to try some stuff tomorrow.

His '84 sat for about 6 years, and now everything that could go wrong did. My '74 sat for 6 years, and before I removed the gas tank (for resto purposes), it fired every time you turn the key.

 

You could try putting your carb on his truck an seeing what it does....

 

I recommended that. We'll probably try it. The only problem is that his truck is auto, mine is manual, so I have no kickdown.

 

That doesn't make any difference. The kickdown has nothing to do with the way it runs. That is just a passing gear.

 

good. We'll try mine then.

 

Keep us updated...

 

Sounds like some thing in the needle and seat. Its spoused shut of the fuel flow when the bowl gets full.

 

Love your ford dude....