Electric Fuel Pump & OP Safety Installation

All Models and Years
User avatar
BrooklynCorvair
Posts: 31
Joined: Fri Jan 06, 2012 10:53 am

Electric Fuel Pump & OP Safety Installation

Post by BrooklynCorvair »

The oil in my '66 Monza 110 stinks of fuel and I'm pretty sure it's the mechanical fuel pump leaking into the crankcase. So I ordered the Airtex E8016S Electric Fuel Pump as well as the plug for the old fuel pump hole and a conversion fitting for the fuel lines.

I'm now left with three questions (for now):

1) Would this Oil Pressure Safety Switch work?

2) Can I install the OP Safety switch in place of the OP sender for the idiot light?

3) What type of relay would I need, and what's the best way to set up the wiring and a bypass switch so that I'll be able to prime the carbs when necessary?

Please pardon my newbness and my very limited knowledge of auto mechanics. I did research some posts on electric pump installs, but they're lacking in the details necessary for a newb dummy such as myself.
Last edited by BrooklynCorvair on Mon May 21, 2012 12:59 pm, edited 1 time in total.

User avatar
azdave
Corvair of the Year
Corvair of the Year
Posts: 1978
Joined: Fri Dec 11, 2009 1:27 pm
Location: Phoenix, AZ

Re: Electric Fuel Pump & OP Safety Installation

Post by azdave »

I don't know the exact wiring details of that switch but it should work fine. The new switch will provide a contact for the fuel pump relay only while there is good oil pressure. When the oil pressure is too low it should shut off the fuel pump and also turn on the idiot light.

In cases where you have no oil pressure yet but need to fill the carb bowls (after long term storage for instance) you can install a wire from the starter energizing wire to the fuel pump relay (you will need a diode to prevent backfeeding the starter solenoid) and this will run the fuel pump while the starter is engaged. You could also easily install a hidden momentary switch in the engine compartment to temorarily run the pump only.

Inertia (crash) switches are another good safety device when using electric fuel pumps. I find them on ebay.
Dave W. from Gilbert, AZ
65 Corsa 140/4
66 Corsa 140/4
66 Corsa 140/4 w/factory A/C
66 Corsa 455 Toro V8
65 Monza Convertible 110/4
66 Monza Convertible 140/4
65 Monza 4DR 140/PG w/factory A/C
65 Monza 4DR EJ20T/5

User avatar
BrooklynCorvair
Posts: 31
Joined: Fri Jan 06, 2012 10:53 am

Re: Electric Fuel Pump & OP Safety Installation

Post by BrooklynCorvair »

azdave wrote:I don't know the exact wiring details of that switch but it should work fine. The new switch will provide a contact for the fuel pump relay only while there is good oil pressure. When the oil pressure is too low it should shut off the fuel pump and also turn on the idiot light.

In cases where you have no oil pressure yet but need to fill the carb bowls (after long term storage for instance) you can install a wire from the starter energizing wire to the fuel pump relay (you will need a diode to prevent backfeeding the starter solenoid) and this will run the fuel pump while the starter is engaged. You could also easily install a hidden momentary switch in the engine compartment to temorarily run the pump only.

Inertia (crash) switches are another good safety device when using electric fuel pumps. I find them on ebay.
Thanks azdave! I'm having trouble finding what type of relay I would need, can you help me find one that I can order online? I think it's supposed to be a 5-pin 30A relay? It would probably be better to get a fused one as well, right?

User avatar
azdave
Corvair of the Year
Corvair of the Year
Posts: 1978
Joined: Fri Dec 11, 2009 1:27 pm
Location: Phoenix, AZ

Re: Electric Fuel Pump & OP Safety Installation

Post by azdave »

These are nice relays and come with a pigtail. You won't need anywhere near 30-40 amps but no harm in using a higher rating.
http://www.summitracing.com/parts/PCO-5591PT/

Yes, always fuse new wiring installations as close to the battery as possible.
http://www.summitracing.com/parts/PCO-0950PT/
Dave W. from Gilbert, AZ
65 Corsa 140/4
66 Corsa 140/4
66 Corsa 140/4 w/factory A/C
66 Corsa 455 Toro V8
65 Monza Convertible 110/4
66 Monza Convertible 140/4
65 Monza 4DR 140/PG w/factory A/C
65 Monza 4DR EJ20T/5

martyscarr
Posts: 293
Joined: Sun Dec 13, 2009 10:33 am
Location: Eugene, OR

Re: Electric Fuel Pump & OP Safety Installation

Post by martyscarr »

Here's a wiring diagram that might help:
oil pressure switch with relay.jpg
Marty Scarr

User avatar
BrooklynCorvair
Posts: 31
Joined: Fri Jan 06, 2012 10:53 am

Re: Electric Fuel Pump & OP Safety Installation

Post by BrooklynCorvair »

That's perfect! Thanks so much Marty!

User avatar
BrooklynCorvair
Posts: 31
Joined: Fri Jan 06, 2012 10:53 am

Re: Electric Fuel Pump & OP Safety Installation

Post by BrooklynCorvair »

azdave wrote:These are nice relays and come with a pigtail. You won't need anywhere near 30-40 amps but no harm in using a higher rating.
http://www.summitracing.com/parts/PCO-5591PT/

Yes, always fuse new wiring installations as close to the battery as possible.
http://www.summitracing.com/parts/PCO-0950PT/
Thanks Dave! I just ordered a comparable relay and fuse holder on ebay. Now I just need to figure out how to bypass the OP switch for when I need to prime the carbs. I have some extra push button switches that might work, which I can mount somewhere under the dash. I just need to figure out how to wire it.

User avatar
BrooklynCorvair
Posts: 31
Joined: Fri Jan 06, 2012 10:53 am

Re: Electric Fuel Pump & OP Safety Installation

Post by BrooklynCorvair »

For the push button switch that I plan to mount somewhere under the dash to bypass the OP Safety Switch for priming carbs, could I go with an on/off/on SPDT rocker switch such as this one, where:

On1 = OP Safety Switch
Off = Fuel Pump cut-off (anti-theft)
On2 = 12V Direct for priming carbs

???

User avatar
azdave
Corvair of the Year
Corvair of the Year
Posts: 1978
Joined: Fri Dec 11, 2009 1:27 pm
Location: Phoenix, AZ

Re: Electric Fuel Pump & OP Safety Installation

Post by azdave »

Yes but I like this one better for safety. The switch direction for priming is momentary so you could never accidentally leave the switch in the "prime" position.

http://www.ebay.com/itm/DPDT-Center-Off ... 1c25373d54
Dave W. from Gilbert, AZ
65 Corsa 140/4
66 Corsa 140/4
66 Corsa 140/4 w/factory A/C
66 Corsa 455 Toro V8
65 Monza Convertible 110/4
66 Monza Convertible 140/4
65 Monza 4DR 140/PG w/factory A/C
65 Monza 4DR EJ20T/5

User avatar
BrooklynCorvair
Posts: 31
Joined: Fri Jan 06, 2012 10:53 am

Re: Electric Fuel Pump & OP Safety Installation

Post by BrooklynCorvair »

azdave wrote:Yes but I like this one better for safety. The switch direction for priming is momentary so you could never accidentally leave the switch in the "prime" position.

http://www.ebay.com/itm/DPDT-Center-Off ... 1c25373d54
Great idea! Thanks again Dave! Although I'll only need a single pole switch. I'll try to find an SPDT with a single-sided momentary.

User avatar
azdave
Corvair of the Year
Corvair of the Year
Posts: 1978
Joined: Fri Dec 11, 2009 1:27 pm
Location: Phoenix, AZ

Re: Electric Fuel Pump & OP Safety Installation

Post by azdave »

BrooklynCorvair wrote: Although I'll only need a single pole switch. I'll try to find an SPDT with a single-sided momentary.
Why bother looking for a single pole? No harm using a DPDT. You can jumper the contacts to create a double amperage SPDT if you really want to.
Dave W. from Gilbert, AZ
65 Corsa 140/4
66 Corsa 140/4
66 Corsa 140/4 w/factory A/C
66 Corsa 455 Toro V8
65 Monza Convertible 110/4
66 Monza Convertible 140/4
65 Monza 4DR 140/PG w/factory A/C
65 Monza 4DR EJ20T/5

User avatar
BrooklynCorvair
Posts: 31
Joined: Fri Jan 06, 2012 10:53 am

Re: Electric Fuel Pump & OP Safety Installation

Post by BrooklynCorvair »

Yeah, you're right. I ended up buying that DPDT switch. Thanks! I just figured I'd look for an SPDT just so I'd be sure not to screw up the wiring in my newb dumbness.

One more question please...
Would I need a fuel pressure regulator even though the Airtex is rated at 2.5 - 4.5 PSI? And if it is recommended that I get one, would this one work?
Also, I've read somewhere that with modern day fuel, I could actually run fuel pressure lower than the standard 4.5 PSI - as low as 3 PSI could work fine. Any truth to that?

User avatar
azdave
Corvair of the Year
Corvair of the Year
Posts: 1978
Joined: Fri Dec 11, 2009 1:27 pm
Location: Phoenix, AZ

Re: Electric Fuel Pump & OP Safety Installation

Post by azdave »

BrooklynCorvair wrote: One more question please...
Would I need a fuel pressure regulator even though the Airtex is rated at 2.5 - 4.5 PSI? And if it is recommended that I get one, would this one work?
Also, I've read somewhere that with modern day fuel, I could actually run fuel pressure lower than the standard 4.5 PSI - as low as 3 PSI could work fine. Any truth to that?
Don't install a FPR unless you know you need one. It's one less part to buy and maintain. Summit Racing generally has good stuff so it probably would be okay if you are forced to use one.

With carbs you simply need enough fuel flow to keep to bowls topped off under all normal conditions. Too much fuel pressure will overcome the seat seals at the float arm and you'll be overfilling the bowls. Running lower pressure will risk not being able to keep the bowls filled during periods of high fuel use.

If at 3 PSI your fuel bowls are staying full then you are okay to run lower pressure. I don't see how modern fuels have much to do with whether you run 3 PSI or 4.5 PSI since you are simply mainting a liquid level inside the carb. Re-jetting the carbs for modern fuels is maybe what you are thinking of.
Dave W. from Gilbert, AZ
65 Corsa 140/4
66 Corsa 140/4
66 Corsa 140/4 w/factory A/C
66 Corsa 455 Toro V8
65 Monza Convertible 110/4
66 Monza Convertible 140/4
65 Monza 4DR 140/PG w/factory A/C
65 Monza 4DR EJ20T/5

User avatar
BrooklynCorvair
Posts: 31
Joined: Fri Jan 06, 2012 10:53 am

Re: Electric Fuel Pump & OP Safety Installation

Post by BrooklynCorvair »

Sounds good, I'll try it without a FPR and see how it goes. Thanks again Dave! You've been a great help!

User avatar
BrooklynCorvair
Posts: 31
Joined: Fri Jan 06, 2012 10:53 am

Re: Electric Fuel Pump & OP Safety Installation

Post by BrooklynCorvair »

So I finally installed the EFP (E8016S) but I didn't connect it to the fuel lines yet. I just mounted it, ran the positive to beneath the dash and wired the relay and toggle switch. Then I made the big newb mistake. I thought I'd be a smart perfectionist and test my wiring work to make sure it's all correct before I reroute the fuel lines. I figured powering the pump dry for only a few seconds shouldn't do much harm. I killed the pump. It came on for a few seconds and then died. I ordered a replacement and now learned my lesson on powering fuel pumps dry. Also, when I powered the pump, that was just with the toggle switch in the "prime carbs" position. I then used a circuit tester to test if I get power via the relay and it didn't work and I don't know why. However, I called Airtex tech support and they told me that since the pump only pulls around 2 amps, a FP relay, although a good safety precaution, is not absolutely necessary. So I think I'm gonna forget about the relay and just wire direct to an ignition switched power source. This install is turning out to be a major PITA. :doh:

User avatar
azdave
Corvair of the Year
Corvair of the Year
Posts: 1978
Joined: Fri Dec 11, 2009 1:27 pm
Location: Phoenix, AZ

Re: Electric Fuel Pump & OP Safety Installation

Post by azdave »

BrooklynCorvair wrote:This install is turning out to be a major PITA. :doh:

That's why some folks hate them. I use electric pumps when the need arrises but I won't take out a good working mechanical pump unless there is good reason. If a mechanical pump fails on me I usually switch to electric at that time because I like the benefits of no vapor lock issues, theft protection (hidden switch) and being able to fill the carb bowls before cranking the engine.
Dave W. from Gilbert, AZ
65 Corsa 140/4
66 Corsa 140/4
66 Corsa 140/4 w/factory A/C
66 Corsa 455 Toro V8
65 Monza Convertible 110/4
66 Monza Convertible 140/4
65 Monza 4DR 140/PG w/factory A/C
65 Monza 4DR EJ20T/5

Post Reply

Return to “Ask your Mechanical Questions here”