Hey guys,

I've got a 1986 Ford F250 (unleaded, 3/4 ton, 460 big block engine). It has less than 31,000 miles on it.

It sat for about 6 years until just recently, and wouldn't start.

I replaced the solenoid and spark plugs, charged the battery and it started right up. Drove it around for about an hour, and then while on the road it just randomly died. No vibrations, sputter, weird sounds, no warning — it just seized up. I don't know if this has anything to do with the problem, but I had turned on the vent and A/C to test them just before it stalled out (about 30-45 seconds before).

I towed it home and have done the following:

New master break cylinder, new break booster, new starter relay, new distributor caps and wiring, dropped and cleaned fuel tank of varnish, cleaned out the fuel lined under the truck, replaced fuel lines in the engine compartment with flexible lines, new fuel filters, new fuel pump in the tank.

Now, it sounds like it wants to start — it almost sounds like it is going to turn over, but then it sputters a little and continues to try and crank, but it just won't turn over.

If anyone has any tips, ideas for troubleshooting, or thoughts, I'd be greatly appreciated. I've spent a lot of time on this truck and it really is in great condition, I'd love to see it running and I know it wants to!

The only thing left I'm going to try and do is clean and rebuild the carburetor, other than that I am at a loss.

I also made sure the emergency fuel shut off switch wasn't tripped and I can see fuel entering the fuel filter and lines in the engine just before the carburetor.

Thanks in advance for any advice, I greatly appreciate it!

 

Have you checked to see if your getting fuel inside the carb? Look inside the air horn while moving the throttle linkage. You should see fuel squirting thru the venturi. If you don't see any fuel, try taking a screwdriver and tapping on the top of the carb where the fuel line enters the carb. You might have a stuck needle.

 

Thanks for the exceedingly quick response. I will try that here within the hour and post back my results.

If anyone else has any ideas/tips, please keep them coming. This truck is too sweet to rot away in a junk yard!

I could also make an audio recording of the truck trying to start if anyone has an "ear" for this sort of thing, let me know if that would be helpful.

 

I moved the throttle linkage back and forth but didn't see any fuel squirting, however when I tried to start it yesterday I did see a little fuel squirt out the top of the back of the carb. See this picture with a blue circle around the part the fuel came out of:

http://www.applesource.us/f250.jpg

I've tried tapping the top of the carb where the fuel lines enter, but it still won't start. It sounded like it was really going to, even turned twice and chugged like it was started but then it sputtered and started cranking again.

It's either something small and stupidly easy to fix, otherwise it is the carburetor sucking too hard and getting clogged with something, could still be some varnish chunks up in the end of the fuel lines. If I could just get it started I'd let it run and fill the tank so it could filter through.

The fuel filter is filling with fuel, I do know that, so the lines and the pump are working well.

Thanks so much for any help you can provide.

 

It could also be that you have a torn accelerator pump. You might want to rebuild it. Could also be that you have some varnish built up inside the carb too.

 

I'm betting it's the carb. got it off and the underside is coated with varnish in the fuel intake manifolds. I'm gonna try to open it up and scrape it clean. a rebuilt carb is about $400 so if I can avoid that I'd prefer it.

 

A kit is about 25 bucks or so. They're not too hard to rebuild, just take your time, and let it soak good.

 

also the carb was not properly torqued down on the block, whoever worked on this truck last did not know what they were doing most likely. I'm gonna soak the carb overnight in B12 Chemtool and then try putting it back to spec, just need to get ahold of a proper torque wrench.

 

found a rebuild kit for $45. I'll pick that up if soaking the old one doesn't do the trick.

 

You'll need to replace the old gaskets, so you might as well get it. Plus its got all the adjustment specs.

 

the gaskets look perfectly fine, but I don't really know. looks like the main problem is everything is just really sticky. a good soak and a proper install may just do the trick.

 

Well good luck. Let us know if theres anything else.

 

thanks for your help, I really appreciate it. if this doesnt fix it and a rebuild kit doesnt fix it I'll take some video if the engine trying to start and maybe that will provide more clues.

 

one more quick question - it looks like on the carb, on the side opposite the fuel filter is a plate covering a gasket with six strange bolts, seems like a proprietary tool is required. it's on a plate that says 34R-6153B. what tool do I need to remove this? I can post a picture if that helps.

 

Got it, it's called a clutch bit in case anyone needs to know.