fire in the hole, but some fuel pump questions

Belgian1979vette

Well-known member
Joined
Apr 4, 2008
Messages
1,706
Location
Koersel/Belgium
Well, after a lot of issues and wiring problems yesterday I finally succeeded in firing up the engine on megasquirt FI.

Not even difficult to start, which, I guess, is a good sign.

BUT : my Aeromotive A1000 is one loud MF. I use a surge tank, with a Holley HP125 pump supplying the surge tank and then the A1000 supplying the high pressure. All pumps are well below the level of either fuel tank or surge tank, so that's not the issue. Fuel lines are large enough so that's not a problem either.

But the Aeromotive is so loud I'm not going to leave it in there.

Would like some suggestions on a good pump with some 400 lbs/hr flow at 45 psi pressure and silent...

Input is appreciated.
 
shoot a vid, it's not that loud normally... aeration/cavitation makes them very loud. You will need at least a -10 line on either side, period. Same for filters, -10 or larger. If your rails are -6 or -8 run them split parrallel and use a regulator with a -10 return.
 
I'm out for the moment because I'm doing work on the fuel system.

The pump has all -10 in and out lines. The filter is the proprietary Aeromotive filter with -10 in and outlet. The bypass is also the proprietary Aermotive with -10 inlets and a -6 return. Pump is lower than the surge tank so it should feed the pump all by itself.

Not sure what's going on.
 
You say the pump is noisey?? how do you have it mounted?? I tied my FI pump to the rear frame rail with nothing but a hose section wrapped around it for sound deadening, and a hose clamp to the frame, so essentially it's mounted in rubber, cuts lots of noise down.....:smash::thumbs:
 
the sound in this clip is similar.

https://www.youtube.com/watch?v=VtvoNUZXIXQ

Its mounted in the front of the feet of the passenger on the firewall. Only spot up front I could mount it.

WHY up front??? like mine, it's a FI pump, and so mount it on the REAR frame with rubber isolation....but mine is a cheap parts house thing, about 2" round and 6" long.....suction on one end, and output and electric on the other end....and certainly not near that amount of noise....no where NEAR even if mounted on a sounding board....

:thumbs::eek:
 
the sound in this clip is similar.

https://www.youtube.com/watch?v=VtvoNUZXIXQ

Its mounted in the front of the feet of the passenger on the firewall. Only spot up front I could mount it.

WHY up front??? like mine, it's a FI pump, and so mount it on the REAR frame with rubber isolation....but mine is a cheap parts house thing, about 2" round and 6" long.....suction on one end, and output and electric on the other end....and certainly not near that amount of noise....no where NEAR even if mounted on a sounding board....

:thumbs::eek:

Gene, I didn't want to mess with air getting in the lines leaning out fuel on top and melting pistons or so. I couldn't modify my stock tank since it is the bladder tank, which is why I'm using a surge tank. Only place I could mount it was in the right fender. Pump needs to be lower than the surge tank, so not a lot of options there.

Seriously considering taking it out and using a Holley 12-1400 dominator in its place. They say it's silent, but that was said about the A1000 as well....
 
I just have a batch fire L98 setup, 355" and roller cam....essentially a ZZ4 engine, since my car was a '72 the tank had no bladder in it, and it was replaced by previous owners, I too have a 'surge tank' mounted up front and lower than the main tank, my reason for it was to keep the fuel flowing in a turn when the tank got near empty, engine would die/buck/surge soon as the fuel sloshed to one side, so I got a steel 5 gallon air tank and mounted it forward of main tank and lower, return line goes to the surge tank, main tank drains into surge tank, pump takes fuel from bottom of surge tank, I have a locking vented cap, and a more or less stock evap emissions charcoal canister with that black plastic float valve on the left/forward side of the main tank.....

I WAS getting some fuel smells in the garage when tank was full, but at only 50% full there was none....I was scratching my ass but good over that one, finally pulling the rubber rain boot off the filler neck, and found the leak, it was some odd looking fitting off to the left on top of the tank, I cleaned it off and poured epoxy all over it, never an issue since then.....

I even have the fuel filter on the suction side of the pump, and use the stock 3/8 - 5/16? lines for supply and return, not ever an issue in spite of all the guys saying otherwise.....:harhar::smash::thumbs:
 
:surrender: OH, forgot to mention...no spare tire/carrier...some steel was welded to the air tank, and goes forward to the old carrier bolt position, and the handle of the tank is bolted to the main fuel tank brace.....:eek:
 
Is the srge tank pressurized? Mount a 5psi cracking 1 way valve on the return of the surge tank. It will bleed off vapor and force feed the pump. In that clip you hear cavitation. The pump is creating bubbles and it probably gets warm to the touch.

Do you have it running full speed all the time? Might want to get a pump controller.


Sent from my GT-I9505 using Tapatalk
 
Is the srge tank pressurized? Mount a 5psi cracking 1 way valve on the return of the surge tank. It will bleed off vapor and force feed the pump. In that clip you hear cavitation. The pump is creating bubbles and it probably gets warm to the touch.

Do you have it running full speed all the time? Might want to get a pump controller.


Sent from my GT-I9505 using Tapatalk

Back along about '75 or so, I put a CARTER electric pump in the trunk of my '72 Lemans with a Qjet carb, and the pump put out too much pressure, it was forcing the float valve open, and so I did the easy way out....stuck a series resistor in the +12 feed, to drop the voltage/power down and so the pump ran for years that way.....years later I did an inline pressure regulator....with no return line, I just remember the dial was green and chrome.....it worked ok too.....been a while.....:surrender:
 
Is the srge tank pressurized? Mount a 5psi cracking 1 way valve on the return of the surge tank. It will bleed off vapor and force feed the pump. In that clip you hear cavitation. The pump is creating bubbles and it probably gets warm to the touch.

Do you have it running full speed all the time? Might want to get a pump controller.


Sent from my GT-I9505 using Tapatalk

A Holley HP125 pump is feeding the surge tank. It uses the stock feed and return. Since the return is smaller I assume it creates some pressure. I left it like that as it will help feed the high pressure pump. I can see a good stream in the tank so that should work.

If air is in the system, it can only be up on top in the tank, but the fittings are almost as high as the roof of he surge tank, so any air should get pushed out to the fuel tank if you ask me.

The A1000 is lower than the surge tank, so it should have no issues with cavitation as it's gravity fed by it.

No, I don't have a pump controller, so it runs full power.

I was thinking going to a Holley 12-1400. I heard comments saying they are pretty much silent. For the price of a controller I have the Holley pump.
 
I swapped my A1000 stuff for a billet holley pump and filters also, mine is an 800 HPish pump, it works just fine. All issues gone after swapping

My surge tank setup:

2525c7935c3e2e.jpg

holley pump setup
%255BUNSET%255D.jpg
 
Is it silent ?

Well, you have at least the luxury of room. The holley is a little wider than the A1000 and gets closer to my header.
 
Last edited:
Backpressure valve

Hey TT what 5 psi backpressure valve do you use? I'd like to build a little back pressure in my surge tank. The tank is not readily accessable (PIA to get to)so I'd like to use a proven piece. Do you have a maker and part#?

Thanks,

Grampy
 
If the return line is smaller than the feed line, inevitably it will build some pressure. Starting the low pressure feed pump on mine, I can see the needle move some on the fuel pressure regulator, so it does provide pressure.
 
Top