Fuel System: 50 comander vapor lock

[doubledaddy]

My 50 land cruiser will vapor lock driving down the road. I can raise the hood while it is running and the gas is boiling in the filter at the carburator and it will boil for about 15 min after shut down. I have had it die while drive around 30 mph and it cuts in and out at highway speeds. I spray the fuel pump with starting fluid to cool it and the boiling stops almost at once but comes back in about 30 seconds. All this just idling in the drive way. I changed the fuel pump but it did not help. I have never had a car vapor lock this bad. I installed an electric pump at the rear and it hasn't stalled yet but the gas is still boiling in the filter. I bypassed the mechanical pump, just running on the electric and everything seems ok, no boiling, but the pressure is only 2 psi at idle, around 5 psi with the mechanical pump. Is this enough pressure. Any ideas why the fuel pump is getting this hot?

[Studebaker1962]

I am very close to being done on my return line and will post with hopefully success.

Jim

[doubledaddy]

That may well solve the problem. Allowing fuel to pass thru the pump faster should help cool it. In the past I have seen cars with aluminum fins attached to the fule pump and gas line trying to cool the pump with limited sucess. Mine does not have any metal lines around the motor, it;s all hoses. The car came from Minneapolis and it has an engine block heater and I am thinking it may have a high temp thermostat, can't tell. The temp guage does not work and I'm working on that. Have not checked the heat riser to se if it is stuck closed.

[dickeedee]

I have a '64 Cruiser 289, and have had numerous issues concerning vapour lock.
Last year I blocked off the intake crossover, rerouted the fuel line, and insulated it, put spacers under the carb, and replaced the fuel pump.
I thought I had it beat, until I was in line at the Detroit bridge border in Aug., it started acting up again.(of all places to have that happen).It did it a couple of times after that., I always try to use High Test, w/o ethanol.
This year, I have added an electric fuel pump, and removed the heat riser..
If it continues, I am going to do what Jim did above.
If it still does it after that
, I'll try a road flare..

[doofus]

Doubledaddy, wasnt there a heat shield kit for champ and commander 6's. keeps exhaust heat away from pump. fix temp guage and replace thermostat first. sounds like engine running to hot now. then see what happens. Luck Doofus

[Studebaker1962]

Dickeedee,

Don't get crazy with the road flares. Only drive on roads without curbs, you can coast over on the grass, have a cooler with drinks and a few snack bars. Enjoy the "time out" to cool off. As I said I am so close to finishing my return line. Will report back to the forum.

Jim

[dickeedee]

Dickeedee,

Don't get crazy with the road flares. Only drive on roads without curbs, you can coast over on the grass, have a cooler with drinks and a few snack bars. Enjoy the "time out" to cool off. As I said I am so close to finishing my return line. Will report back to the forum.

Jim

My luck, the thing will go up in flames and some over zealous Insurance investigator will pull up this conversation!
I'm anxious to see if that does the trick for you.
Was that restrictor orfice in the fuel filter?
If it was , do you remember the Napa #?

[TWChamp]

I have some white plastic spit tubing, just like the common black plastic tuving used for a wiring harness. My Model A had bad fuel boiling problems when using the ethanol crap gas, and the Model A has gravity feed to the carb, and only a couple feet of steel line under the hood. The white plastic wrap helped a lot, and I would try that on the Studebaker. Between that and the electric fuel pump, I can't imagine the problem would still exist. I wonder if a person can still buy some pipe wrap like the asbestos we used to get to wrap exhaust manifolds and exhaust pipes? That would keep the heat down a lot, and you could also use it to wrap the fuel line.

[Studebaker1962]

The NAPA filter is "NAPA Gold" 3054

Jim

[Studebaker1962]

[deco_droid]

Doubledaddy, I am in Texas as well (in fact, I think I met you once when I came by to look at some spare parts)... Anyway, just thought I would add that I have not had any problem with vapor lock on my Commander, and I am still using a mechanical fuel pump and running our only choice ethanol gas. The fuel lines are all where the factory put them originally as well. Just thought that may help you narrow down your problem.

[studegary]

I would first question if your car has its fuel pump heat shield in place. Many of these were left off when the pump was replaced. You can either buy a new or used replacement or make one up, if needed. It may not entirely solve your problem, but it would be a good start.

[doubledaddy]

I have tried most suggestions with no luck. Even with it running the filter looks like a coffee percolator. I have not yet tried a heat shield on the pump, there is one on the carb. I bypassed the mechanical pump and went straight to the carb. This solved the vapor lock but the electric pump is only holding 2 psi, it's a cheap inline pulse type and is not able to keep up. It runs fine at 65 mph but starts sputtering when I try to accelerate for more then about 5 seconds.

I can't see the pressure guage while moving so don't know what's happening to the pressure. Think tomorrow I'm going to run a temporary line inside so I can see the guage.

Can anyone suggest a good 6 volt electric fuel pump? I have looked at the Carter P4259, add says it will deliver over 70 gph with a max pressure of 7-8 psi.

Think the return line off the NAPA filter may be something to try also. I found several old car fourms that listed this as a fix.

[Dick Steinkamp]

"Ethanol crap gas" is not contributing to vapor lock...

"The higher the volatility of the fuel, the more likely it is that vapor lock will occur. Historically, gasoline was a more volatile distillate than it is now and was more prone to vapor lock."

and..

"Vapor lock is also less common in other motor sports, such as Formula One and IndyCar racing, due to the use of fuel injection and alcohol fuels (ethanol or methanol), which have a lower vapor pressure than gasoline."

Cars vapor lock LESS today because of our Ethanol crap gas...not more. There are at least 2 posters here who run non ethanol gas and still experience what they feel is vapor lock. I have owned at least 30 vintage cars in the last 15 years all running e10 and no vapor lock in any of them, even on hot days at altitude.


Also, IMHO, "vapor lock" becomes the quick diagnosis for a variety of poor running, stalling, and hard starting conditions. It seems odd to me that the same car(s) experience what the owner feels is vapor lock, but others on the same day with similar (or identical) cars do not. Post #11 is a good example of this. Once the owner has diagnosed their problem as "vapor lock", the search ends for what is probably the real cause.

Common causes of symptoms similar to vapor lock include:
1. Sediment in the fuel tank that periodically blocks the pick up.
2. Collapsed soft lines that restrict or halt the flow (especially as they get warm and softer)
3. Plugged fuel filters or sediment bowls
4. Weak fuel pumps
5. Blocked carb float bowl vent
6. Incorrect carb float setting
7. Carb that needs rebuilding
8. Pin hole(s) in the fuel line, or insecure hose clamps.
9. Ignition problems (especially coil and/or condenser that fail as they warm up)
10. Blocked fuel tank vent

[kurtruk]

" I have not yet tried a heat shield on the pump,"


It is a factory part. It is (was) there for a reason. SI sells them. Item# 187748