Electric fuel pump question

[paraclete comes]

Ok read about half a dozen electric fuel pump threads, trying to find the answer to my question. I've seen it posted in another thread but didn't see an answer. so here it is.

If and when I install an electric pump (already bought an airtex for a chevy diesel van) do I need to have it running all the time if my mechanical pump is working? I pretty much want to use this as a back up, in case the mechanical pump goes down while I'm out on a trip or in the hills. Was planning on wiring it up to its own dedicated switch so I can flip it on as needed.

If this has already been answered please excuse me, but am really curious if that will work. I don't want to install it and have it impede the mechanical pump if the electric is not on.

 

[Keith_J]

Not a good idea, mechanical pumps are diaphragm type and failure mode is ruptured diaphragm. If you were to use an electric, it would either draw air (down stream of mechanical pump) or force fuel through the diaphragm (upstream of mechanical pump).

Fuel pumps are easy to change, I've done it on Loop 610 in Houston in rush hour traffic.

 

[paraclete comes]

hmm ok, thanks for the info. Anyone else have any input on the use of an electric?

 

[zout]

Depending on fuel pressure needs - There are Rotary vane types - there are solenoid activated - so you could use one on each line with two switch's.

See how much fuel pressure you need and you might have to purchase a fuel pressure regulator - this you can tap both lines into as it has one inlet and two outlets - some have dual both sides. Then regulate your fuel pressure with an in line gauge to get it dialed in.

 

[kenz5380]

I have the Mr. Gasket Electric pump and I use it just like you described. I have it wired to a switch in the dash and I pretty much use it for starting when the truck has been sitting for a long time. I shut it off after I start it up. I haven't changed out my fuel filter since I've had the new pump on there but I'm looking forward to not having to crank the heck out of the motor to purge the air from the fuel system. I've been running with this set up for about 1000 miles and have not had any issues.

 

[paraclete comes]

I have the Mr. Gasket Electric pump and I use it just like you described. I have it wired to a switch in the dash and I pretty much use it for starting when the truck has been sitting for a long time. I shut it off after I start it up. I haven't changed out my fuel filter since I've had the new pump on there but I'm looking forward to not having to crank the heck out of the motor to purge the air from the fuel system. I've been running with this set up for about 1000 miles and have not had any issues.

Thats good info, I read a ford forum where a guy had this set up for years with no issues. Anyone else have a similar set up using an electric just for back up or for priming and using the mechanical pump for driving?

 

[wallew]

I'm confused. Why would you NOT want a consistent 5 - 6 psi delivery of fuel TO the mechanical pump?

It makes the mechanical pump work LESS, not more. And on the OFF CHANCE that the mechanical pump fails you still get fuel.

Why would you consider this a problem?

And by adding the electric pump but not using it, you will never know when/if it fails until you flip the switch and nothing happens.

 

[paraclete comes]

im on board with the electric back up pump aiding. In regard to having it off until needed I cant think why a quality pump like airtex would not work on demand in a pinch if you never use it, except to prime a filter or something.

 

[corelokt]

Perhaps he is thinking of fuel being pushed into the crankcase if the diaphragm ruptures.

 

[Herewego]

I know this thread is a few months old but I'm curious to what you decided, Paraclete Comes? I would like to add an electric fuel pump as a backup and for priming as you described. There seems to be many schools of thought when it comes to this install. Thanks.

 

[MarcusOReallyus]

Why make this complicated? Install the electric pump to be on when the key is on, and get rid of the mechanical pump. Done.

 

[Vhyle]

Hmm... haven't entertained the idea of an electric pump as a mechanical pump primer/backup.

Does it install right in the tank like a stock Chevy or are you guys talking about an in-line?

 

[MarcusOReallyus]

In-line. Goes inside the frame rail. Wired to be on when ignition is on. (Use a relay, and fuse it!)

Remove the mechanical pump. Get a block-off plate that fits a Chevy 350 block to close the hole where the mechanical pump used to live.

Done.


Lots of good info & pictures in this thread: http://www.steelsoldiers.com/showthread.php?48444-Electric-fuel-Pump-install

 

[francisf16]

I added one to mine in prep to remove the mech lift pump for a turbo install and it made my truck run stronger. I guess my mech pump wasnt giving it enough pressure by itself.

 

[yamabro]

I've been fighting this same battle