[pont406]

Got A problem with my fuel system upgrade on my 66 Lemans, brand new 12 G fuel cell, (i rinsed it out with gas prior to installation) new #8 braided line, cell to carb, new dual line AN carb inlet setup, new Holley pressure gauge and regulator,( Dead head setup) USED Mallory 140 pump, i flushed the braided line to the front of the car (ran pump, placed line into bucket) before hooking to regulator/carb, started it up easily, got regulator set at 6 1/2, shut it off, started it up, and the idle was bouncing from 850 RPM down to 500 RPM, (almost died) i reved it to 2500, several time to clear it out, it idled fine after that, (pressure steady at 6/7 psi) let it idle until it got up to 175 degrees, (like 5 minutes) then the pump started surging loudly and the gauge was going to 9 psi then down to 3psi, then back to between 6 and 9, motor didn't change tone except when it went down to 3psi, did this for several minutes, the pump was quite a bit noisier and hot to the touch. float levels were right in the middle( Demon carb with sight bowls) what your opinion?

[screamingchief]

The pump is cavitating (noisy & hot),and it wont last long if the root problem does'nt get fixed pronto.

From the pics,first thing of note is that fuel pump is mounted improperly,it must be mounted vertically with the motor on top.

Also,the use of a deadhead reg. will often force the pump to bypass internally quite a bit,so understand that the more a pump like this bypasses internally,the greater the chance it will cavitate eventually as that often aerates the fuel,and thus heats up the fuel/pump quite a bit.

So make sure the internal bypass is not the source of the problem here.

If somebody had that "USED" pump set-up for use with a bypass/return style regulator,they may have disabled the pumps internal bypass completely,and that wont work with a deadhead reg. as it no longer can bypass fuel when the pressure climbs under low demand use.

So that also should be checked.

A small fixed orifice "bleed" with a small return line plumbed into the system before the reg. would help with the pressure fluctuation/surging situation somewhat.

It also helps keep the pump from bypassing internally to the point of aeration/cavitation.

Also be sure the pre-filter is'nt too restrictive as well.

The initial problem (idle speed bouncing around) sounded like there was some air trapped in the line,but that should have taken care of itself pretty quickly,this other stuff sounds much more worrisome to me.

That stuff is pretty much where I would start.

[pont406]

Thanks Brett, I think i'm gonna take the Mallory pump off, I've got a Brand new Holley "red" pump in my stash, i'll make a bracket for it to mount it vertically, hook it up and see how it does, cars running in the low 13's/high 12's right now so it should be fine!

[67cruiser]

406, Personaly i also don,t think your reg. should be mounted over the intake and water goose neck like that, Keep it away from a nasty diasater incase of a leak!!Get the reg. mounted on a bracket or near maybe the firewall. I personally would of added another 2 ft. section of line in there. Totally agree with the chief man return line is needed, I am running a 140 pump and ive read it can be mounted anyway, up down sideways,

[screamingchief]

Originally Posted by 67cruiser

406, Personaly i also don,t think your reg. should be mounted over the intake and water goose neck like that, Keep it away from a nasty diasater incase of a leak!!Get the reg. mounted on a bracket or near maybe the firewall.

Cant mount regs on the firewall,that's not legal per NHRA/IHRA.

They must be mounted at least 6" forward of the firewall.

I'd be more concerned with vibration affecting his reg. mounted like it is vs. a leak.

A leak can start a fire regardless of where the reg is mounted,with it mounted on the firewall that outcome may even be more likely than with it mounted on the engine,as a leak on the firewall would almost certainly drop gas right on the very hot exhaust pipes.

Originally Posted by 67cruiser

I am running a 140 pump and ive read it can be mounted anyway, up down sideways,

Not according to the instructions from Mallory.

See clip below.

See step 2,the text in bold @ the end of the paragraph.

HTH.

[Tom Vaught]

Motor ALWAYS ON TOP!

Tom Vaught

[pont406]

Ok Update, took off the Mallory pump, mounted a new Holley red pump, (see pics) fuel pressure was 6 lbs steady, but adjusting reg didn't change pressure at all, knowing the the "red" pump is preset to 7 max, i change the pressure spring to a "blue" spring, set reg a 7psi, ran fine for about 5 minutes, then gauge drops to 0 psi ! pump got warm, shut it off, took the round filter screen out of the fuel filter, making it open flow, no restriction, pressure went up 2 1/2 lbs!, adjusted it back to 7 psi, ran fine for about 5 minutes, then same thing, drops to 0 psi, pump gets hot! could the line running from the cell to the pump have to much drop making the pump unable to bypass? remember it's a Deadhead setup see pics.the "red" spring didn't seem to have this problem,

[ponjohn]

Try running it without the inlet filter ( just for troubleshooting) sounds like it is running out of fuel.

[pont406]

Originally Posted by ponjohn

Try running it without the inlet filter ( just for troubleshooting) sounds like it is running out of fuel.

I took the filter screen disk out of it making it an empty shell, as stated in other post, didn't fix the issue, gonna redo ground wire and check voltage, if that's not the problem, gonna try another pump

[grandville455]

Are u running a relay for the pump?

[pont406]

No, but i have a Painless relay kit in my stash for my race car project, I currently just have a 12 gauge wire running out of fuse box with a circut breaker block on it. I ran a Carter HP electric pump with no problems for years thru the factory fuel lines with this wiring setup i'm gonna check voltage and run a ground to battery and see what that does.

[67cruiser]

Pont. 406, unless my ole eye,s are seeing it wrong , it looks like you are going from a no.8 line to the filter correct, and may i ask did you reduce it down to a no.6 to the pump?? It just looks like it to me, all those extra fittings, filter looks like a no.6 also??? It seems like you start out great then why go smaller??

[pont406]

Originally Posted by 67cruiser

Pont. 406, unless my ole eye,s are seeing it wrong , it looks like you are going from a no.8 line to the filter correct, and may i ask did you reduce it down to a no.6 to the pump?? It just looks like it to me, all those extra fittings, filter looks like a no.6 also??? It seems like you start out great then why go smaller??

No it's all #8, that a double female #8 AN after the filter, checked voltage at pump while running, got 14 volts, ran a 12 gauge ground to the battery, problem still there, starts fine runs for 5 minutes, pump gets hot, psi goes from 6 to 0 psi ! must be a bad pump i guess.

[grandville455]

Two Pumps? samething? Kinda wierd don't ya think?.. Do the gallon test.. see how long it takes to fill a 2 gallon can or 1 if u have it... see if its starving the pump thats why its getting hot?

[67cruiser]

I am running a return line back to my tank, i don,t seem to be having that problem at all.

[pont406]

Originally Posted by grandville455

Two Pumps? samething? Kinda wierd don't ya think?.. Do the gallon test.. see how long it takes to fill a 2 gallon can or 1 if u have it... see if its starving the pump thats why its getting hot?

Tell me about it, I think the Mallory pump was cavating because of the filter(40 micron) and maybe being mounted sideways, and being used could have been modded for return reg like Brett said, Holley "red" was supposed to be new,never used, got it from a friend a few years back (real cheap!) called Holley tech, he said it sounded like a bad pump to him, after i answered all his questions. tried "red" pump with and without filter, no restriction possible other than filter, no difference! it has 14 volts at the pump, that's enough isn't it?ran a 12 g ground directly to battery from pump no difference! bought a new "red" pump last night gonna try it i guess. know alot of people who have run holley "blue" and "red" pumps with reg,no returns on street strip cars, and had no issues!

[grandville455]

Fuel is a wonderful thing isn't it ... I just went thru alot of BS Myself!!.. But In the end it's worth it right? ,lol

[old66tiger]

What kind of vent are you running on the tank?

[pont406]

Originally Posted by old66tiger

What kind of vent are you running on the tank?

6 AN aeroquip push lock hose with a 90 on top and a bulkhead going thru the floor, tried letting it run with the cap off, didn't change anything, installed a BNIB Holley red pump tonite, let it idle for 10 minutes with no change in pressure, so i may have fixed it, gonna road test it tomorrow, and then will see if it fixed!

[chuckies76ta]

Has anyone tried one of these electric fuel pumps?

Thanks
Charles

http://www.barrygrant.com/bgfuel/default.aspx?page=44