Hello All! Glad to have found the site, and hope it can help a newbie... I recently purchased a 1948 Chrysler Windsor on a whim at auction for $2300. Runs and drives, all original I'm told (except the paint) including gl***, interior, engine, transmission, chrome, etc. It's a neat car for sure! I have run into only 1 problem so far. On longer drives (over 60 minutes) on warm days (75+), she tends to die, starving for fuel. An aftermarket plastic see-thru fuel filter has been installed just prior to the carb, and it is bone dry when she fails. After cooling for a few hours, she'll start back up and drive again, with the filter being full. I have replaced the mechanical pump with a new rebuilt one, but that didn't fix it. Vapor lock is my next guess...any thoughts? Would an electric pump help me here? Do I by-p*** the mech pump? What should the fuel pressure be from an electric? This is still very stock, 6v, positive ground... Any thoughts would be greatly appreciated!
Loosen the gas cap - your vent line for the fuel tank may be blocked . Also when it quits feel of the fuel line between the pump and carb to see if it's hot . One of the cures from back in the day was wooden clothes pins placed on the fuel line.
What size engine is in the Windsor? I would trace the fuel line from the tank to the carburetor, and replace all rubber hoses. You could have a weak hose collapsing. Also, check to see that a heat shield is installed between the exhaust manifold and fuel pump. I am guessing , here, as I am not familiar with the Windsor. However, it was common Mopar practice to have a heat shield protecting the fuel pump and fuel lines from exhaust manifold heat. Without the shield you may have vapor lock problems. Finally, the pump should put out around 4.5 lbs. pressure. Again, I don't have a manual, but 4.5 would be typical Mopar for this era.
I believe this has to has to be a myth. Wood doesn't conduct heat, people sometimes make carb spacer plates out of wood for that reason. I did find some metal clothes pins(along with some wooden ones) on a steel fuel line once, @ least they have the potential to disipate heat.
I'm not as well versed as I hope to be...it is the flat-head straight 6 (251?) Spitfire with Fluid Drive Transmission. The mech pump is bolted into the block towards the bottom on the p***enger side. Runs off the crank I guessing? So I'm not sure about a heat shield as the pump is not too close to the exhaust manifold. As far as my novice knowledge tells me, the basics of the system are the tank in back, fuel line to the pump, fuel line from the pump straight up to the carb with a fuel filter spliced in just before the carb. Does that make sense? And yes, the metal lines from the pump to the carb were hot to the touch when she failed...
Sounds like a good chance of vapor lock then, Shield or rerout. Wooden clothes pins not likely to help.
There should be a metal shield between the fuel pump and th line but old mopars seldom have the "dreaded vapor lock problem, as the fule pump is at the same level as the bottom of the tank, so gravity does most of the work. they do have an oilite filter on the pickup in the tank. and it can get clogged. The rubber line between the pump and the front crossmember can collapse under vacuum, there is also a br*** screen between chambers of the fuel pump, and a hollow bolt that secures the chambers together and p***es fule between the chambers. These can get clogged also. But the easiest first thing to do is put some low pressure compressed air into the line from the intake sie of the pump. This will blow any sediment away from the pick up and cleanout the in tank filter. Then check the hose it may look good on the outside but be gummy on the inside. Also new replacement Mexican pumps have fulcrum pins that are not staked properly and can work out which ca cause partial or complete failure of the pump. When you have done the air thing, disconnect the out let at the carb and direct the flow into a suitable container. Have and ***istant crank the starter with the coil wire disconnected and count 12 pulse from the pump you should have 8 to 10 ounces of fuel in the container. That will ***ure you have proper flow capacity. If you have less than that, then start looking fow air leaks on the vacuum side of the pump back to the tank. But in 90% of the cases the air and or a new rubber line will set you up.
Here is a picture of a Dodge military engine, but the fuel pump heat shield should look very similar on the Windsor 251. The shield attaches to the exhaust manifold forward-most nut.
The heat shield also attaches to a stud on the fuel pump. Thee is a template for the shield in the downloads section of the P15-D 24 website. This site specializes in Mopar Flathead 6 powered cars and other vehicles. Lots of good stuff on the Imperial Club site inthe repairs section, too.
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