My 1970 F-350 with 360ci has a Motorcraft D4PE-BGA Carb which hot soaks. I have to hold the gas pedal to the floor to hot start, starts normally when cold. I installed a manual choke and rebuilt the carb. The carb has a spacer under it that flows coolant thru it. I have read a phenolic carburetor spacer may help. Should I leave the coolant piece in place, or remove it to install the phenolic spacer? If I leave it, should the spacer go above or below the coolant manifold? I live in southern central Tennessee. Thanks, Doug

 

Probably don't need the heated spacer. I had the same issue with a 69 I owned and tried everything, still peculated the gas out and flooded the truck. I put on a 350 Holley and that cured it.

 

Try using pure gasoline if you can get it in your area. Ethanol will tend to create this situation more so than gasoline. I switched back from using (cheaper at the pump) 10% ethanol-90% gas to pure gas for just this reason and the problem is much diminished. My increase in fuel mileage makes the extra pump cost of pure gasoline a wash, when you figure the additional BTUs in a gallon of gasoline get you farther than a gallon of ethanol does.

The next bit of troubleshooting you can do is make sure you don't have an imperfection in the carb float needle valve. A scuff or scratch in the seat, or a worn needle can cause just enough leakage of fuel under pressure into the bowl, until it floods over into the manifold. If this is ruled out, try adjusting the float just a little bit lower so that the level of fuel doesn't expand it.

Contrary to common opinion, you'll tend to have more boil-over if you remove the hot water spacer between the carb and manifold. It serves to moderate the heat absorption of the carburetor associated with temperature rise in a just-shut off engine. In fact, removing the hot water spacer often causes this problem where it didn't exist before.

 

I cured this same problem on my 69 by running the thicker carb base gasket from a late model truck.

 

Part number E5SZ9A589A spacer.

 

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Part number E5HZ9C477A.

 

I cured my x in laws 70 c/s just by passing the heated base oem spacer.

 

I took out my spacer too. I replaced with these exact pieces. Working good so far. Haven't had to floor it to start yet but it's only been about a month.

Edit: I forgot to mention I also had re-route my PCV to the back of the carb.

 

I had the same setup and the same problem on my 69 with 390 engine, I installed a phenolic carburetor spacer and never have had a problem again. It was 108 deg here last week and my truck started normally. After about 30 min I shut it off. About 10 min later it restarted just perfect. Since I live in a high desert area, I gave the heated spacer away.