Electric fuel pump plumbing

[XFChris 126]

The mechanical fuel pump on my xflow was dead, so I put in a low PSI electric fuel pump.

 

Plumbed like so:

Tank>OEM lines>Electric Pump+ filter>rubber hose>Petrol lock off solenoid (dual fuel car)>rubber hose>Speedflow fittings>carb

 

I have heard the electric pumps can burn out if they build up too much pressure between them and the carby.

 

I am thinking of putting in a T fitting somewhere between the pump and carb so I can let excess fuel run to the factory fuel tank return line.

 

 

How have others running electric pumps done this?

[ronny 204]

Pump needs a relief

Some people pump the fuel all the way to the motor (reg) and return from there

I prefer to have the relief right after the pump back to the tank so the fuel heats up less (not near hot engine bay)

[slydog 7,873]

I have just converted mine to this pump relief set up as well via hydraulic check valve and T piece.First thins to say was how much quieter the pump is compared to a long return line.

[XFChris 126]

Thanks guys.

 

I'm new to the world of fittings, regulators and such.

 

So i'd just need to go to the fitting shop, and ask for a fitting with a relief? Or is the setup more complex than that?

[ando76 4,354]

yeah they work much better with some form of relief.  I love the hydraulic check valve at the pump - like I installed on Rob's pump.  You wont believe just how much fuel is relieved internally until you fit a relief and see the amount of fuel that passes over it. 

Makes for a happier pump and much better fuel supply to the carb. 

[XFChris 126]

What does the check valve setup look like? I didn't spot a pic of it in Rob's thread.

 

Also, what PSI check valve?

[slydog 7,873]

Yeah come on Rob make with the pictures ya knob...

[slydog 7,873]

But to be serious the fuel system is bolted to a dyno ATM so no pics yet guys...but as a reference 

 

http://www.parker.com/portal/site/PARKER/menuitem.de7b26ee6a659c147cf26710237ad1ca/?vgnextoid=fcc9b5bbec622110VgnVCM10000032a71dacRCRD&vgnextfmt=default&vgnextdiv=687505&vgnextcatid=1537938&vgnextcat=CLS%20%20IN-LINE%20CHECK%20VALVES&redirect=true

[ando76 4,354]

 

 

 

This is the system I did on Jason's speedway car. Just used dirty old hydraulic t piece as Jason is on a budget but you can get nice alloy fittings as well. The big silver thing sitting vertically is the check valve. It is set at 7.5psi so as soon as the pressure in the system reaches 7.5psi (no demand from the bowl) fuel will relieve to tank - instead of being internally relieved in the pump. That is what gives the pumps that terrible groaning noise and hurts fuel quality.

 

I have since replaced that dodgy bit of hose and clamp (Jason's work) with a fitting that bolts the filter directly to the valve. You may think a filter is not important on the return but you will be surprised by the amount of metal these pumps make.

 

Hope that clears it up.

[bear351c 10,270]

Also, a lot of electric pumps like to 'push' fuel, not pull. Mounting closer to the tank and down low, may help. Up high in the engine bay may cause issue.

[ando76 4,354]

yeah bear I've heard this but I've also seen a Holley blue pull fuel when it was mounted on the inner fenderwall on the passenger side of a XY falcon.  It was pulling fuel from the original fuel tank.

 

Now I'm not saying this is ideal at all but it worked - much to my surprise.  I agree with closest to the tank and low to ensure that it doesn't have to work so hard and also to make plumbing the return a lot simpler and cheaper

[bear351c 10,270]

Holley blue (and red) have a fairly good rep. Dare say they're a bit better quality than the chinese ones. I run a Carter on my inner guard in the engine bay, no issues.

[hendrixhc 10,920]

Where on an XE have people mounted said Holley 

blues?

[unfamilia 1,938]

Any one using those $35 faccet pumps iff ebay? So if I plumbed it in under rear passenger guard near tank just add a t peice straight after it back into tank returnline? Maybe 10cm away from tank so wouldbt build up heat.

Would that be the go in this situation

[ando76 4,354]

Yeah unfamilia that sounds good.  Jason bought some cheap pumps off e-bay and they were basically a straight holley copy.  We used them with methanol without an issue -even tho they are not rated for meth.  One died after a year and a half of use without a check valve - since we put a check valve on Jason's we have not had an issue.  It does get a petrol flush after each meeting and is kept wet so that has not doubt helped. 

the choice is yours mate.  either way make sure you have a filter on the outboard side of the pump and on the return to tanks because those style of pumps make a lot of metal and you don't want that stuff going through you carb, valve seats etc. etc.

[unfamilia 1,938]

Would check valve really be needed or will t peice running costant back to tank be enough

[ando76 4,354]

If you do it that way you will run the risk of running out of supply when there is demand as your effectively halving the efficiency of the pump on the supply side.  You may as well just go and buy and old clacker pump if that is your plan.

 

So, short answer - yes the check valve is required to take the load off the pump if you go for a big volume pump like a holley red/blue.

 

You can run the pump without one but you WILL

a) shorten the life of your pump dramatically

use excess electrical energy because the pump will be relieving internally and that puts extra load on the motor driving the pump

c) super heat and aerate your fuel

d) have to put up with the racket the pump makes - even if you rubber mount them yadda - yadda. AND FINALLY

e) use more fuel.

 

A hydraulic check valve will set you back about $45 dollars and you can get the fittings cheap as.  Why would you even contemplate running a pump without one?  PM Slydog and ask him how much quieter his pump ran with the check valve in line and just how much fuel past over the relief.

[XFChris 126]

My fuel pump is a cheap 'facet' style off ebay. It looks the same as the GOSS pumps SCA sell but without the branding.

 

I have changed my fuel system a bit, no pics as my phone camera won't play ball ATM.

 

After the pump, I have put in a hydraulic T piece. One outlet runs direct to the carb, with a Ryco Z14 filter in place.

 

The other outlet has a 0.5 bar check  valve put in, which runs to the factory fuel return line to tank, I put a cheap SCA brand filter in the rubber hose there.

 

Pump is not that much quieter, but idle seems a little smoother. I haven't done a road test yet.

 

I got my t piece, check valve and barbs from Pirtek for just under $50 all up.

[slydog 7,873]

Here's mine as it was bolted to the engine cradle for dyno day...

 

[ando76 4,354]

XFChris did you look at the amount of fuel going over the relief at all?  It usually scare most people. 

[XFChris 126]

The fuel filter I have on the return line has a clear housing.

 

Check valve is fixed at 7.25psi. Lots of fuel flowing back to the tank at idle. I might take a vid sometime.

[unfamilia 1,938]

Wonder if it needs a relief valve? I know others dont use relief valves with faccet pumps. Would a restricter work in the return line so fuel just constantly trickles back instead of constant fuol flow back to tank and to carb?

Yes the $50 seems daunting to my cheap nature

[ando76 4,354]

Well unfamiliar your question is answered by XFChris and the amount of fuel returning to the tank at idle. THAT is the idea of the check valve (relief).  Without it ALL that fuel would have been relieved internally in the pump!!!!!

 

No you can't just run a restrictor in the return line.  You still need the volume of fuel at full noise or under load - if you have fuel trickling back to the tank all the time you are losing volume.  The relief only returns fuel to the tank when there is NO demand - which takes the load off the pump. 

 

$50 barely buys you a decent carton of beer.  Stick to the formula and you will reap the rewards - deviate and cheap scape it and you will not get the results. 

 

This idea was developed by a very good friend of mine who is a hydraulics expert.  We have been using it for about ten years now - without incident.  I'm yet to see a cheaper more effective upgrade for cheap fuel pumps. 

 

If you need further proof have a look at all the top line electric fuel pumps - magnafuel etc.  they all have a relief (adjustable even).

[unfamilia 1,938]

Cool ando. $50 buys good mid strength but when I buy it it has to last 8-10 weeks fir a slab currently

[XFChris 126]

Road testing has not gone too well.

 

I am getting vapor lock issues and  stumbling under load. (which I assume is due to insufficent fuel pressure at the carb)

 

-I've then insulated the fuel line from the T piece to the carb, but it hasn't made a noticeable difference to stumbing.

 

-I may need to insulate the return line ( as it starts from where the charcoal canister is). Or I need to look into using a higher PSI check valve.

 

I'll just go back to my old setup with no T piece for now and see if it runs nicely on petrol again.