Electric fuel pump users

[CST10]

Hello. I recently installed a holley red electric fuel pump to rid my issues around vapor lock. I was wondering if others have done the same was the pump kinda loud. Mine is, but I guess it's from mounting inside the frame rails.

Also anybody have any issues with this pump. A friend said it would flood his carb at first causing issues. He also said without the relay kit it could drain the battery.

[dirtyjim]

I've ran both holley red and blue pumps and they are loud.
you should be able to run the holley red without a regulator but I would still check the pressure at the carb if your running a edeljunk carb.
I would definitely run it off a relay so you will get full battery voltage to it, they can run hot it they don't get 12+ volts.

[CST10]

I have a holley carb. Pressure at start up is 7-7.5 psi and around 5.5 psi after it has warmed up all the way and been running for awhile.

I bought the painless relay for it but haven't installed it yet.

Any other issues. How long do they typically last. How reliable are they?

[davepl]

I have electric pump systems in two cars. One is EFI so I control it that way. The other I used a diesel lift pump relay from a Silverado to prime the carb (runs the pump for about 10 seconds on first power).

I would strongly encourage anyone using an electric pump to put an inertia interrupt switch inline with the power (or relay trigger). If you crash you don't want your pump filling the intersection with gasoline while you're sitting there. I got mine from a Ford Explorer.

Here's one on eBay. For $15 how can you go wrong?

http://www.ebay.com/itm/92-95-Mustan...4c2435&vxp=mtr

[69chevytrucker]

Originally Posted by davepl

I have electric pump systems in two cars. One is EFI so I control it that way. The other I used a diesel lift pump relay from a Silverado to prime the carb (runs the pump for about 10 seconds on first power).

I would strongly encourage anyone using an electric pump to put an inertia interrupt switch inline with the power (or relay trigger). If you crash you don't want your pump filling the intersection with gasoline while you're sitting there. I got mine from a Ford Explorer.

Here's one on eBay. For $15 how can you go wrong?

http://www.ebay.com/itm/92-95-Mustan...4c2435&vxp=mtr

if i crash after all the work i have done to my truck i want it to burn to the ground lol

[CST10]

How is that inertia interrupt switch installed/wired into the system?

[CURSED GEARS]

I'm using a Holley red pump. Ran it through a relay, and also my oil pressure switch. If I lose oil pressure, it cuts off the pump. Use a regulater too to keep the 2-3 pounds of pressure to my Holley 94's. Got it mounted on a rubber pad, but its still loud.

[davepl]

I've only been in one serious accident, but the engine kept running. The fender had been ripped away and the positive post ripped off the battery, but the alternator was still there so it just sat there running.

An inertia switch would have killed it. Oil pressure wouldn't. That's why the OEMs put them in vehicles in the first place, right?

To each their own.

[CURSED GEARS]

Originally Posted by davepl

I've only been in one serious accident, but the engine kept running. The fender had been ripped away and the positive post ripped off the battery, but the alternator was still there so it just sat there running.

An inertia switch would have killed it. Oil pressure wouldn't. That's why the OEMs put them in vehicles in the first place, right?

To each their own.

Never heard of a inertia switch until this thread. Something to think about.

[Fitz]

Originally Posted by CURSED GEARS

Never heard of a inertia switch until this thread. Something to think about.

My friend's very expensive Alfa Romeo 4C has one. It's been towed back to the dealer six times since he took delivery last November. When it gets hot here in the desert the pavement expands then pressure cracks form. Most have just a one inch raised ridge at the crack but some of the streets here haven't been repaved in 10 years or so and those pressure ridges are 3 inches high. Imagine hitting a ridge 3 inches high and 6 inches wide at 40 mph. When he hits one of those, the inertia switch kills everything and the car goes back to the dealer on a roll-back to have the switch replaced. There is no way to reset one. If you're looking for another really big Pain In The A, this is a good one to have. You will never know when it will leave you stranded out in the middle of BumFxxx , Egypt so, if you're too far from the cell tower to get any bars you get a nice hike! If it's a cool day which is hard to find in the desert.

[bs46488]

I have been researching the loud fuel pump issue for my Nova project. Other forums suggested trying a Carter pump.

I was also going to check out the Airtex E8120 for my application.

The inertia switch is certainly something I just added to my build to-do list. Thanks!

[michael bustamante]

Does anyone have. Diagram to wire up an inertia switch?

[Keith Seymore]

I have a holley pump on two of my vehicles ('65 GTO and '74 Chevelle).

In each case they are mounted back by the tanke and deadheaded into a mechanical pump on the engine. I have them wired to a toggle switch and run them during periods of high demand (like during a burnout or 1/4 mile run). The rest of the time I run around on just the mechanical pump.

They used to last forever, but it seems the last few years I have to put a new one on every spring, after sitting through the winter. They are also a little loud, but the noise is structureborn and to be expected - plus I like to know that they are working.

K

[cdowns]

vapor lock is mostly a mythical problem that uninspired newbies choose not to address and fix the underlying cause

[Fitz]

Originally Posted by michael bustamante

Does anyone have. Diagram to wire up an inertia switch?

Wiring is the easy part. It's a three axis (LEFT-RIGHT, FRONT-BACK, UP-DOWN) switch and it needs to be mounted where hitting a pothole won't set it off. With the finely tuned, soft and luxurious ride these trucks have, I wish you luck in finding such a place.

[CST10]

How is that inertia interrupt switch installed/wired into the system?

I don't know if vapor lock is a myth or not, but the electric fuel pump solved my issue. The mechanical would drop pressure just sitting still. I checked or changed the carb, sending unit, girl line and the mechanical pump and the issue would not go away.......until i installed an electric fuel pump.

[dirtyjim]

inertia switches are pretty easy to wire, and they need to be wired into the trigger wire for the relay, they are not meant to run the pump through them.
if its a two wire switch just wire it inline with the relay trigger wire, if its a three wire switch the should be marked C, NC, NO
you will run 12volts to C, NC goes to the relay trigger, NO can be used to activate a dash lamp to tell you the witch has been tripped or it can be left out

the mythical vapor lock problem sometimes is difficult to diagnose and fix since the boiling point of fuel can vary drastically from formula to formula, station to station, time of year and even altitude can come into play.
I've only experienced it with edeljunk and quadrajet carbs, never with a holley. the quadrajet had a glass inline filter that you could actually see the fuel boil in at times. a 1" plastic spacer solved the mythical vaporlock problem on my edeljunk carb

[davepl]

Originally Posted by dirtyjim

I've only experienced it with edeljunk and quadrajet carbs, never with a holley. the quadrajet had a glass inline filter that you could actually see the fuel boil in at times. a 1" plastic spacer solved the mythical vaporlock problem on my edeljunk carb

I would definitely use it on the relay trigger myself, but the factory wires are decent gauge so they may have actually interrupted power directly. You'd have to find out what the switch is rated for in amps.

As for Holleys, they didn't make that heat shield that everyone bought for no reason... In fact the ONLY time I've ever had fuel boil was on a Holley, never on a QJet. Besides, Holleys are generally self-cooling as they just dump raw fuel into your engine. OK, not really.

Also, glass filters are Satan's jewelry. They're seriously dangerous unless mounted very carefully. If they flop around your intake it's just a car fire waiting to happen (not picking on you, just on those filters in general).

[dirtyjim]

the glass filter was on the truck for the hour and a half ride home when I bought the truck, when I got it home I replaced the fuel line from the pump to the carb and put the filter back in the inlet fitting that the p.o. left out.
a good friend of mine lost his truck because of one of those filters

[CST10]

Thanks for the drawing Fitz.

So these inert switches aren't resettable?

I also see some chatter around glass inline fuel filters, while I don't have one it makes me think of another question.

Should I install a filter before the electric fuel pump? I have one at the carb now.

[CURSED GEARS]

I have. Initially I didnt have one, and the pump stopped working. I took it apart to find metal shavings in it, (from my fabbed gas tank) Put it back together and it worked again. Now, I got a filter between the tanks and the pump.

[Fitz]

Originally Posted by CST10

Thanks for the drawing Fitz.

So these inert switches aren't resettable?

I also see some chatter around glass inline fuel filters, while I don't have one it makes me think of another question.

Should I install a filter before the electric fuel pump? I have one at the carb now.

Some are resettable and some are not. The Corvette switches have a reset button them right at the top but none of the foreign ones do. ALWAYS install a filter before the pump. These pumps are not very tolerant of dirt or crumbs of rust inside them. Just be sure that the filter is in an accessible place. The pump is cooled by fuel and if the flow is choked off by a dirty filter you will be buying a new one.

[dirtyjim]

most inertia switches are resettable, just press the button on top to reset

[davepl]

Originally Posted by dirtyjim

most inertia switches are resettable, just press the button on top to reset

The Ford ones that I use certainly are. And if you whack them they trip and yet I've had wheel hop and so on and never falsely triggered it.

[CST10]

Thanks for the info. Gunna install a filter before the pump and an inert switch too.