Packard Forum Index » Pre-War (1899-1942)

OK everyone,I was coming home from a car show last Sat. and all of a sudden my car, (a 1937 120) started to hesitate every now in then as if it was starving for gas. It was hot and over 95 degrees but I really hadn't been stopped for any lenght of time so the car really wasn't over heated. My question is......How do you tell if it is a carb. problem, a fuel pump problem, or just a fuel filter problem?? I went looking for the fuel filter, and see it's in a pretty tight place. Are these easy to change out, as I think I would want to start there first. Any help would be appreciated. Thanks

Sounds like vapor lock to me. A "pulse type" electric fuel pump in line will solve it. I do not know where to find a 6V one, but surely someone makes one.

Craig

I concur, sounds like vapor lock. The best thing to do is make sure the heat shields on the carb and fuel pump are present, as well as adding the fuel pump. Personally, I'd go as far as running a return line from the carb back to the thank, and your problem will be solved completely.

Cut open the filter to see how much crud is in it. Mite have to wait till it dries out. USE A MAGNET to see if the crud is rust. If so the n disconnect fuel line at tank and pump then blow compressed air thru the line. CATCH the crud (if any) that comes out for verification.

Check for a bad condenser and also the vacuum advance.
Greg

My question is......How do you tell if it is a carb. problem, a fuel pump problem, or just a fuel filter problem??

The poster got some good advice but I notice no one really answered his question. In my own experience vapor lock is generally diagnosed mostly by process of elimination. I can suggest that he perform a fuel pump pressure and volume test in addition to changing the filters, and removing any before the pump.

I'd also suggest that a failing ignition coil could give the symptoms he notes.

"My question is......How do you tell if it is a carb. problem, a fuel pump problem, or just a fuel filter problem"

Ok. The answer to that question is the same answer as to any diagnostic. Start with the ez diagnostics FIRST.

Is there gas in the tank????
Is the gas cap vent clear?????
Filter dirty????
kinked or faulty hose between tank and line or line and pump???
Is there any sign of gas leakage anywhere????
Is the carb bowl vent plugged up with debris?????

That's a start.

Hi there,

Had the same problem recently, we had a heat-wave here and once the temp. gauge reached 180 the car started to stall and was hard to start again. When I looked at a glass fuel filter installed just before the carb I noticed a large amount of air in it. (I had preformed all the usefull checks I was advised to do by the wiser heads on this forum at the time)

The upshot is that it seemed to be vapour lock. As a stop gap measure I have wrapped the fuel lines and carb in a heat reflective tape and, while not pretty, it has solved my problem. I will, as advised, set up a return line to the tank to keep the fuel temp down.

Pat.

Thanks for all the great advise. I will take this list and try to work things out. I did notice that I do not have a heat shield. Was this standard equipment, or were these aftermarket?