The Stovebolt Site Forums The Shop Area Engine Shop Fuel Line

because fo vapor lock (on 80 degree days) I was wondering it I could re-route my fuel line to get away from this problem. Possibly run a rubber line over the top of the engine and straight down.

I tried insuating it, but it didn't change anything. Could it possibly be my fuel pump gets that hot?

Thanks
Brian K

49 chevy 235 engine

BrianK: I don't think I would want to run a rubber hose over top of motor (Retired firefighter) anyway are you sure you are vapor locking. Another trick is to feed your steel line thru a rubber hose still looks nice and then reflare your ends. Try the aluminium foil wraped around the fuel pump first might be a way to isolate the problem. Ya never know. popcorn
The Truth is Out There (we'll find it)

Five or six wooden clothes-pins on the fuel line will act as a heat-sink and may work as a temporary fix to see if the problem goes away.
If it does, you can work ideas from there.

Vapor lock typically is a suction side problem - between the pump and the tank. Check there for fuel line/exhaust proximity. As long as liquid gets to the pump, it'll push, but if it's sucking vapor you're stopped.

True vapor lock is rare in these trucks with a six. The fuel line from the tank to the pump should be nowhere near the exhaust if your tank is original configuration.

I put some line insulation on the fuel line the other day (not sure what you call it, rubber on the outside, fiber material on the inside) and it had no big affect.

The exahuast comes off the other side of the engine, so that cant be a problem.

----What it does ------

After idling for a few (2 or 3) min. the engine still runs fine, but as soon as you put it into gear and let out of the clutch, it has a verry, verry, shortage of power, and almost dies. Once you push the clutch out, then it runs and raps up fine.

If I pull out the choke about 3/4 of the way, I can make it run good enough to get home (1.5 miles Max)

Thanks for your help

Brian K

I think you need a carburator rebuild. Also check your vacuum advance.

I rebuilt carb. about 2 years ago (400 miles) and my vacume advance works, even if it doesn't work well, and it runs fine until it gets warmed up, and even then. Until I leave it sit still for a little while.

Could it still be the vacume advance?????

Thanks
Brian K

Your heat riser may be frozen. Also try a carb spacer which insulates the carb from the hot manifold.

That is not many miles for two years. Sitting still the carburator actually needs more maintenance than if you were using it daily.

tony,

300 miles of that were within the last month .

Next time it does it, I will check the heat riser, and then, if it is OK, I will check the Carb.

Thanks for all your guy's help
Brian K

Get rid of that rubber hose , it'll make the fuel hotter by retaining heat . (guess how I know)

Also check the fuel pump output pressure - I had one that would vapor lock but always passed the visual volume test - turned out it was dying and only put out 2 PSI maximum ! no wonder it would vapor lock on hot days . a kit or new one (cheap) will fix that .

Last thing , disconnect the line to the inlet of the pump , a _goodly_ stream of gas should come roaring out , not just a thin stream or dribble -
lots of times crud in the fuel tank will block the shutoff valve in the bottom of the tank - these old nails don't have socks/screens on the pickup point in the tank .

Wooden clothes pins will get you going when it vapor locks in traffic but not on rubber hose !.