I have a 75 ford with a 460 and holley 850 double pumper carb. It has sat for a couple of years, and now it will not start. The engine turns over fine, but you have to pour gas down the carb to get it to fire. When it does fire it is only for a couple of seconds, and then it fires back through the carb and dies. What is wrong with it, is there a valve stuck open, timing off, or plug wires hooked up wrong? I have no idea, any help will be appriciated.

 

sounds to me like you have some plug wires crossed, firinf sequence is out of order. Of course your fuel jets may also be clogged, and in need of a rebuild.

 

The gas in the tank and the carb bowl probably went bad long ago. And the needle may be stuck in the seat. What I would do:
Disconnect the fuel pump inlet hose, and plug it.
Put another hose on the fuel pump inlet, other end into a can of good gas.
Pull the coil wire so it won't fire or backfire.
Crank it for 15 seconds at a time, then let starter cool off. Watch the rubber hose from the can, if it starts to pulse, it's probably picking up gas from can.
Looking down the carb, work the throttle linkage and see if the accelerator pump squirts gas when throttle is moved. If not, crank it some more, need to fill the bowl.
If no luck after a while, then the needle may be stuck in the seat, not allowing gas into the carb. Tap lightly on the carb right by the fuel inlet. That might free it up.
Once you get good squirts of gas from the accelerator pump, hook up the coil wire and try to start it.
It's possible that the carb may be gummed up good, and a rebuild kit and cleaning will cure that. Fuel filter too, it may be gummed up.

oh yeah, the backfire out the carb most likely is caused by the mixture going too lean, not surprising considering the conditions. Don't burn your face off pouring gas down a carb, one spit back while your pouring it, and you would be wearing it all over, lit.

 

just a quick question.. you say you have an 850 on a 460 right, ok ,, is this a stock motor?? if it is why do you have an overkill carb on this motor? not needed if it's stock.. if it's built up well then just disreguard. CJ........

 

When I got my 460 it wouldn't start.
After a week of trial and error, I finally pulled the engine out and tore it down.

The Head gaskets were blown out between two cylinders on each bank. One pushrod was seriousle bent and almost worn through. One Exhaust valve was burned badly, and one intake was burned as well. I had to replace them both. The rest of the Valves were pitted pretty good. I was able to lap them clean though.
The Rings were gummed stuck on all the pistons.
The Timing chain was very loose. I think it was on the verge of jumping, it was so bad.
The Gasket under the Carb was blown out in two places.
And last but not least, the Vacuam hoses were cracked and hard. Mostly down on the underside of the sharp bends.

But other than that....

When I rebuilt the engine I put a new cam in. Then I found out there is a Better timing chain drive gear. So when you get a timing set for your truck, get one for a '67 Lincoln' The Timing gear on it has the "0" Degree, while your Post 72 has an 8 degree retard cut.