New to forum, need help with '72 F250

[jpilgrim]

Hi all,

I'm new to the forum. I have a '72 F250 Camper Special with the 360 V8.

Bought it two and a half years ago on CraigsList to help with hauling as I cleaned out my late grandmothers house (and because I was having that itch again for a vintage ride). I've sunk a fair amount of cash into it: many new seals and gaskets, all new power steering. I'm good with electronics and with carpentry, but not very experienced with engines and auto mechanics.

It was riding great yesterday, and now today it cranks and barely starts. You have to floor it to keep it going and it spews gas from near one of the exhaust manifolds. It dies as soon as you let off the gas.

Here's a link to a video of the engine as I try to start it:
http://johnpilgrim.net/FordF250/

So I have two questions:

First, any idea what's going on with the engine. Again, it was running perfectly yesterday.

Second, any recommendations for a good mechanic in San Francisco for a vintage Ford truck like this. I had one I liked in Mountain View, near my grandma's place, but I don't get down their anymore.

Thanks for your help!

John


(Sorry for cross-posts.)

[Case 7230]

I would think you have a problem with the carb fuel level. Either the float valve is defective or the fuel level float is punctured. It is most likely that the float valve is bad or needs cleaned.

[chevyguy]

Time for a carb rebuild. I bet your float is stuck.

[75K30]

Thats a pretty clean "bumpside".
The guys have provided some very educated guesses and I have to agree with the float being the problem. It appears that the carb is permitting too much fuel to enter the engine and is causing all of this.
The procedure is easy, but the motorcraft carbs are known to have bad floats. These get small pinholes in them and they do not regulate fuel properly, and this is the result.
The float is pretty easy to change, and easy to check. You must remove it and see if it has any gas inside. Shake it once it is out to verify.

[jpilgrim]

Thanks for the responses!

Here's another clue:
There's a metal tube coming off of the passenger side exhaust manifold, and going to the carb, that seems to be detached:



I looked through my '72 Truck shop manual but couldn't find what it was.

What is it and could this be the source of some of my troubles.

To respond to some of your questions:

The engine cranks fine and the carb seems to be getting sufficient gas. Some of the cylinders are firing but from the sound and feel, not all are.
Also, the car lives parked on a hill--passenger side uphill, drivers side down. And the gas blowing out of the exhaust manifold seal is on the downhill side.

Lemme know what you think and what that tube is.

Thanks again!
John

[Kennyray]

That tube brings heat from the exhaust which in turn opens the choke. I'm not saying that is all of the problem but could be part of it.

[75K30]

You are correct in that your engine is getting fuel, but the problem is that it is getting far too much. This is the reason why the engine is missing a couple of cylinders. Too much fuel fouls the plugs and you have a mess. You will have to fix this float problem and this should clear up the troubles.

That little heat riser tube has been busted for a while and it is probably not where your problems are at.
Remove the air cleaner and look down the throat (choke horn) and you will probably see all of the fuel pouring in to the engine. This is the problem.

[eponator]

I have to put my vote in for the float as well. Also, about that hill the truck is parked on, as long as its not a very steep grade it shouldn't matter.

[jpilgrim]

Hi all,
Thanks for all your input this week. It really helped me get up to speed on what to be looking at.
Had my truck towed to the mechanic this morning and got it back this afternoon.
Fortunately the problems weren't too deep. Compression tests indicated that the engine was still sound.
The choke was stuck closed and a piece had broken off, which was making the float stick.
So way too much gas and not enough air.
And the exhaust manifold gasket was old and failing at most cylinders.
So the choke was replaced with a used one, the carb cleaned up but not rebuilt, the exhaust manifold gaskets replaced on both sides, and the choke warmer tube reattached to the manifold.
Runs great now, better than it was before it ******* out on Tuesday.
A big shout out to Rescino's Performance Engines in San Francisco for doing great work on the truck.
And thanks again to everyone who helped out in this forum!
Best,
John


(Sorry for cross posts.)

[eponator]

Glad to hear it all worked out. Redoing exhaust gaskets, Why not redo the exhaust!!?? heh, its that kind of thinking that has my checklist of "truck mods" growing and growing... Now, lets see some pics of that 72 beauty!!