I am pretty sure my 66 is getting/ has a case of the vapor lock. It is getting to me and I want to fix it. I have been working alot the last couple days and have not gotten a chance to see if I can locate where the probelm is. I am thinking carb spacer, new fuel pump, check the fuel cap to make sure it vents, change any fuel lines that could be a problem and new rubber fuel lines. What else can i do. I want to drive the truck and solve the probem. Also the truck is a 66 with a 352, 4bbl 4100 autolight and a stock style fuel pump. thanks

 

G'day cbfomoco,

I tried replying yesterday afternoon but it would'nt post for some reason, so I'll try again. I am surprised nobody has replied though ?.

With the limited info. you have supplied I'll take a stab.

I'm assuming that all has been well with the motor, no problems before this vaporizing problem ?.

Assuming this I would suspect a failing fuel pump. If the pump is not up to it then you can expect problems with fuel "purcolation" in Hot Weather. Pressure for a carby vehicle should be in the neighbourhood of 4-7psi. Some Vacuum gauges (hand held diagnostic types) have a Fuel pressure function.

Note that low fuel pressure can result in low fuel levels in the carby fuel bowl and this can lead to engine stumble on acceleration, and cornering and stalling, particularly when braking.

Next would be checking the fuel filters for clogging including the gauze filter in the carby inlet itself. Check the fuel lines as well and if fitted check the fuel return line back to the tank for blockage. Also check the rubber fuel lines for kinking or colapse, this may be causing a restriction. Make sure none of the metal fuel lines are touching or near (less than 1/2") the engine block or exhaust manifolds. The old "Y" block Ford was notorious for this with it's front exit exhaust manifolds radiating Hot Air all over the engine compartment. Are you running headers ?, are these anywhere near the fuel lines ?.

If you are loosing power once mobile I would suspect clogged fuel lines and filters and/or the fuel pump.

Next would be the fuel tank venting issue you mentioned. If there is a problem here coupled with any of the other problems above then you've got a "double whammy".

If it's hard starting when Hot after the vehicle has been parked for say 10-15mins, then you may need to investigate installing a heat-proof spacer between carby and manifold, once you are sure none of the other problems exist.

Hope this helps...........Barry.

 

I had the fuel pump cause this problem in more than one application. I changed to a newer style with out the filter attached it fixed the problem

 

1965/72 FE engines had the fuel filter in the fuel pump originally. Look at your pump, do you see what looks like a tomato juice can with serrated edges? There a cartridge fuel filter inside. The can unscrews, but is prolly stuck, so some penetrating oil should be sprayed around the base before attempting to unscrew it.

C4AZ-9365-A .. Fuel Filter (Motorcraft FG-1)

 

Yep it has that style pump on it and last summer when i got the truck I changed all three filters, (the one on the pump, it has a clear one between the carb and pump, and one at the carb) Also the truck does have duels and stock manfolds. Yesterday I tryed to see if i could find where it was I though I might have a hot line and the only place was the rubber line close to the manfold. I traced the line back to where it goes into the cab and could not find anywhere that felt hot. However the Fuel Pump against the motor was pretty warm. I found a site that sells spacers for fuel pumps that might help any thoughts on that? I am still open to ideas.

 

If you have 3 filters it is a little overkill. I would go for a fuel pump from a 360,390,or other fe engineI think you can get away from the filter in it a 76. If you go with a spacer the rod will be short