The Stovebolt Site Forums The Shop Area Engine Shop Fuel pump question

I have a rebuilt (by others)235 ci in my '53 3600. The fuel pump that was installed does not look like the ones in my manual. Here is a pic http://i982.photobucket.com/albums/ae307/JOHNHILL_photos/53%20Chev%20carb/Carbon235_zpsbf32276b.jpg Can anyone identify? My pump works fine when the engine runs but may be letting the fuel in the line up to the carbs drain back down when it sits for a couple of days. There are no apparent drips. I have a clear fuel filter in the line just before the carbs and after a few days of sitting, it will be empty and it takes most of my battery to crank long enough to get the fuel to the carbs to start. If I try a few hours after a start, it works fine. Could this pump leak internally to let the fuel go back toward the tank? If so, can I get a rebuild kit or should I replace it?
John

There are 1-way check valves inside the pump, inlet and outlet. Use a pressure/vacuum gauge to test it. With the pump output dead-headed into the gauge, idle the engine for a few seconds, running on the fuel in the carburetor. It should produce 3-5 PSI and hold the pressure for a few seconds after shutdown. Then go to the input side and attach the gauge instead of the line from the tank. You should see about 10 inches of vacuum and the check valve should hold the reading for 10-15 seconds. The pump should deliver 1 pint of gas or more into a catch container with a 30-ssecond run at idle.

Summit Racing has brand new Carter fuel pumps (not rebuilt) for Stovebolt engines for about $30.00 that will solve your fuel supply problems for good. "The ABC's of carburetion- - - -Always Buy Carter!"
Jerry

looks like a pretty standard newer pump, don't expect modern replacements to look exactly like what's in a 60 YO manual .... pretty usual with these old engines/carbs that things go dry after sitting for days, you might need to work on using the choke more, hit the pedal and pull choke out full before you start cranking, should start OK without draining the battery .... and of course using it daily is a sure cure

Bill

If I disconnect the pump from the supply line, will fuel drain out of the fuel tank through the disconnected line?

Maybe- - - -have a plug ready to use if necessary.
Jerry

I had the exact same problem with my '57 235 and thought the same thing was happening with fuel leaking out either through the carb or the fuel pump after sitting for a few days. Exact same symptoms as you describe.

Rebuilt the carb and replaced the fuel pump. Same issues.

I now do exactly what red58 mentions above using the choke out full after tapping on the gas a couple of times when the truck has sat for a few days regardless if it is cold out or not. Problem solved.

Matt

A cold engine that starts without using the choke is running WAY too rich! Full choke, crank until the engine fires, then push it about halfway in to keep it from flood-stalling and let the fast idle operate. You should be able to completely release the choke within 1-2 minutes.
Jerry

Mine has two Carter/Webers bought from Tom Langdon. They have auto chokes so I have no override (that I know of).
John

Solution may have been found!
After rereading the advice given, I studied my dual Carter/Webers with electric chokes ( installed new by the fellow that rebuilt my engine)and found that he only had power supplied to the front carb and he wired the choke on the rear one open. I called him to make sure that he had done it on purpose and asked the reason. He claimed that inline sixes only needed one of the two double barrel carbs choked to start and warm up. He recommended installing an inline electric pump in the line before the mechanical pump and turning it on for a few seconds before cranking and off when the engine started.
I thought of what Red58 and Maybellene said about choking and connected a wire to both carbs and cut the restraining wire. It started right up and seems to all be OK. I'll see how it does when it sits a week.
Thanks for the feedback.
John