recently my mech. pump went a friend of mine wired in an electric pump he had on hand. couple of questions . . . . is this "better" than a mech. pump, should i get a block off plate if i keep the electric? and a question about the wiring....... is the pump suppose to run continuously while the key is in the on position? like if i wanted to listen to the radio without truck running .... and also if the key was turned to the left for just the radio , should it be running then ??? b/c mine runs all the time? is it always pumping gas into the carb for as long as i have the key turned ? is this correct? should i just go back to mech? i know alot of ???? any help thanks a lot!!!!! by the way its a 79 350 4wd with a 400. edelbrock carb and intake .

 

I have no idea what you just said.

The pump should be wired off the hot-in-RUN circuit. You should place an inertia switch as well as an oil pressure cut-off switch in the path such that the fuel pump shuts OFF in the event of a collision, or low oil pressure.

You must have wired the pump off the accessory circuit which is wrong. The pump should not be running during conditions in which the motor is not in use.

You are mixing two questions into one. The pump should only be RUNNING with the key in RUN. It should NOT be running with the key in ACC. When the pump is RUNNING, it only pumps as much fuel as allowed by the carburetor. The concept is no different than with a mechanical pump. When the fuel bowl in the carburetor is full, the carburetor inlet is shut off by the needle and seat. The fuel pump continues to run, but does not actually push fuel forward.

Why, what's the problem? Your pump is wired wrong; that doesn't mean a mechanical pump is any better or worse.

Next time, please slow down and use a little more punctuation and fewer abbreviations. Your post looks like a text message and is very hard to read.

 

Personally I would put a new mechanical fuel pump back on.

 

On a carb vehicle I think of the electric pump as a "problem solver". Vapor lock problems in hot weather? The electric pump will help. Really long cranking on an engine that has sat for a while? Electric pump will help. I run an auxiliary electric on another brand 40's era PU with chronic vapor lock problems in hot weather. Problem solved.

My dent is happy with its mechanical pump. Once I got the soggy fuel lines replaced, no fuel problems including 100 degree temps. I think the mechanical pump is best. Its simple, low cost and inherently "safe" since it stops pumping when the engine stops. I'd put a mechanical pump back on personally.

 

My dent is the first vehicle I've ever had that didn't have an aux electric pump added. I ran into my first problem when I ran out of gas and couldn't get the mechanical pump to prime....

I'm now considering piggy-backing an electric one on there to help with this situation and to make starts easier.

 

X2, the mechanical pump will never let you down. the last one lasted 30 plus years?

chris

 

One of my trucks has an electric pump installed by the PO. I'm not sure why. Anyway, it was installed to operate in Run but of course was still a problem. It pumped fuel when the ignition was in run and the engine not running (such as during a stall). Even worse, it could also keep pumping fuel during a ditch or a roll and then you've got fuel going everywhere. I installed an oil switch relay I orderer from Jegs so the pump only runs when the engine is running. Do yourself and your passengers a favour and do the same if you are going electric, or go back to mechanical.