I have an 85 f150 with a 351 windsor h/o with 4 barrel carb. It starts and runs great. It has always ran a little hot. when i cut it off it won't start back up until its cooled off for about 20-30 mins. It acts like the battery is too weak to start it when its hot but like i said it starts up like normal after it cools. Any Ideas?

Many of such carbs required an insulator plate under them to keep from boiling the fuel out. Check with the junkyards.

the pistons are absorbing too much gas flooding the thing I think.

if the carb was put on the car with that gasket sealer stuff you buy in a tube it will get hot and drip down into the carb. I had a car acted the same way and that was the problem.

They also used 5.8L/ 351 windsors as well, and 4 barrel carb on some.

Electric fuel pump most likely has too much pressure for the carb. AFAIK, the Holley 4150/60 & 4165/75 should each demand the usual 4.7-5.3 PSI (4.7 @ idle, 5.3 @ max RPMs), so even the Holley red pump would need some restriction from a regulator. If you want this to be adjusted to its best efficiency, you need to have a fuel pressure gauge installed temporarily, if not on the regulator like I have on my Scout II. FWIW, the regulator I have installed is the Mallory 4307M from CenturyPerformance.com, Summitracing.com, Jegs.com, etc.

http://www.malloryperformance.com/pdf/4307M.pdf

A bad Needle & Seat will do this also, or debris stuck between the Needle and the Seat. This is where light tapping on the bowl helps, but it's best to run the fuel out of the bowl a few times and then the volume flow, or quick filling of the bowl, should loosen up the debris.

You also could have set he fuel float too high. What model carb, the ones I mentioned above (AKA Holley Modular Carbs)? If so, then Holley's site has a tech center & instructions on setting the float(s). www.holley.com

Set the floats carefully and slowly/gradually. Make sure the lock screw is always loose enough before turning the adjustment nut. If you strip out the bowl's threads on an older carb, you'll beat hell finding a replacement. 1/12 turn = 1/32" of fuel height IIRC. You set the fuel level, with pump running (wrap a rag around the carb so gas doesn't leak onto the manifold!!!) so the fuel is just starting to dip out of the "peep-hole" in the side of the float. Removal of the peep/seep-hole screw/plug is necessary first. Clockwise rotation of the nut lowers fuel level IIRC and counter raises fuel level. Again, please check their website. Most people get discouraged when dealing with the Holley Modular Carbs, but they are the simplest and the best carbs on the market. Even if 30+ years old.

Sounds like a problem I had with my '85 Dodge D150 Ram Prospector. In my case, the automatic choke was broken and it was starved for air during acceleration because the choke was always closed. It ran fine at idle or very slow acceleration. I wired the choke open and it runs much better, although it is much more difficult to start as the fuel mix is lean due to the extra air. Once it gets warmed up, though, it runs fine. I hear that the barrel carb on mine often has problems.

have the carb re built

well it could be that you need new spark plugs definatly new piston rings hmmmm was it hard to start before you put the new carb on?

With a new plug and fresh gas it should start. Check to make sure there isn't a kill switch turned off or that the gas petcock from the tank to the carb is on.

How did you check the fuel filter? Disconnecting it from the fuel line that goes to the carb is the best way, making sure the gas is turned on under the tank. Bleed off a little gas into a can or something just to make sure the filter isn't plugged.

The last thing I'd do is take off the air filter and spray a little starting fluid in the carb. It may start and run several times if there is old gas in there somewhere. Remember the bowl on the carb is probably still full of old gas. After some fresh fuel reaches the plug it should start and continue to run.

(You might drain the bowl on the carb of ols gas before you go any further)

Good luck!

Sirwriter

The power for the shutoff relay actually comes from a secondary winding on the ignition coil itself. Why the enging would shut the fuel pump off is that as the engine ran for a while the coil gets warm and then breaks down or opens up the circuit for the fuel shutoff relay. Fixed by replacing $85.00 coil.