Packard Forum Index » V-8 (1955-56)

Well, it would appear on this 97-98 degree very hot day that my '55 Clipper Super vapor locked on me on the interstate at about 60 mph. Never happened before on any of my Packards, not even my warm running '53 Clipper Deluxe. But as it was hesitating I was able to flip on the priming electric pump and it settled out. But I got off the interstate and took back roads home for about 15 miles. Then less than a mile from home turf as I approached the top of a hill, it hesitated and shut down on me before going over the top even with the electric pump on. Started right up and managed to limp home where it idled ok. Checked both filters I have on the car and only a small amount of debris and I would not expect much over the years at all because the tank was renued with the coating in it a few years back. The transparent filter had some discoloration but very little residue in the bottom. My Hudson Super Wasp did a similar thing a couple weeks ago but that isn't anything new for it. And my brother's '56 Lincoln Premiere had to have the primer pump activated on several of the last few outings. The gas must really be getting bad now and they all advertise up to 10% ethanol. Anyone else experience any vapor locking?

This is something that is inevitable to happen on older cars, and the only solution I know of to fix it is to run a return line from the carb back to the fuel tank to keep the fuel constantly in motion and cool the fuel. You will want to either put a restrictor in the return line or use a lot smaller line to return the fuel so your pressure stays up enough to get into the carb. The line has to be after the fuel pump, or it won't work.

It could be the crap we pass off as gas.People all over the world are starving and we keep putting corn in our gas tanks. It destroys old cars.

Actually, if you do the research, ethanol production does not take away from edible corn production. And with all the advances being made in ethanol production by other biomass's, the use of corn is short lived anyway. Ethanol is good stuff if you know how to properly apply it to a vintage vehicle.

Trog. Is there any odor of gasoline from the engine compartment when it happens???? Check the gas cap for venting???

Keith, I thought of the gas cap when after I changed out the filters I had one small backfire and it shut down on me twice. I took the cap off and there was no air or rushing sound at all. But then it fired up and idled ok for awhile. The gas cap scenario may indeed be the culprit on my brother's Lincoln as he changed it ouy and hasn't had the trouble again at least not yet. Don't know what's going on here with these gas caps. I had to get a new one for my Studebaker about a month ago.

Does the vapour lock seem to occur when the gas tank is nearing empty????? When filling the tank try to leave it just a little shy of full to keep the vent TUBE cleared of fuel.

Some modern cars with IN TANK pump and FI will experience short pump life if the tank is always ran near empty due to the lack of gas sloshing around to cool the in-tank pump. Some people run their modern cars near empty most of the time.

If the probelm persists maybe try running with the hood removed. I'm suspicous that hte vapour lock problems reported are occuring in the carb due to heat build up and boiling the gas in the bowl of the carb.

Also not e that the WCFB as used on 56 Clippers needs to have the carb air horn screws tightened from the inner most to t he outer most screws OR a 'bushing installed in the choke vacuum port BETWEEN THE AIR HORN and carb bowl body as outlined in one of the Service Counselors. Symptoms are indicated by engine stall on hard left turns.

My 56 Executive has this problem and i have to tighten the airhorn screws about every 3hree years.

Recently, even in cooler weather, i have experienced hard starting ONLY whe n the engine is HOT. There is sometimes a smell of gas but not always. I'm suspicous that the WCFB vacuum port bushing as described in the SC is needed on my car.

Quite possibly the modern fuels vapour lock easily is true. But if other marginal problems exist then the problem becomes more evident where otherwise symptoms would never be noticed to any negative extent.

Also ceck the heat riser on the left exhaust manifold to be sure it is opening all of the way.

NOTE that i have an 88 F ranger with CARB and MECHANICAL pump on engine. THis truck is in everyday service. NO VAPOR LOCK EVER!

Nearly all 2 stroke string trimmers (used in HOT summer weather sometimes for 2 -4 hours straight) have a built in fuel pump in the carburetor itself. This is why they can run upside down. No vapour lock in those!