12 volts and Walbro fuel pumps

[QWIKSTRIKE]

For those of you running walbro fuel pumps MAKE SURE YOU DO THE 12V MOD, and RUN A 12 VOLT RELAY FOR EACH PUMP USED! I installed my dual fuel pumps and tested both of them in the tank before installing the tank. After making sure they both worked I buttoned everything up, and then I tested the pressure of each pump separately. I found out that the pumps were running less stable when run directly off of the stack setup.The pressure would fluctuate as I tried to set fuel pressure over 35 psi. When I wired every thing to the relay, and ran a wire from the relay to the battery to power the pumps the pressure became stable, and I had no problem making 35+ psi. So if you are runnung a walbro fuel pump, and are not doing the 12 volt mod you may eventuallly ruin the pump, or worse lean out at high hp and blow your motor. When I did this with one pump in the car, and when the gauge fluctuated I thought that the gauge was going bad. When dynoing the guy running the dyno told me he thought the pump was not supplying enough fuel and was weak. I felt this was wrong since the pump was a year old and can support at least 500 HP. Now I know that the pump wasnt getting enough voltage to keep up with the powere being made.

 

[lagged]

hmmm. i must be missing something.

with the stock setup itll kick it over to 12 volts in open loop, and as far as i knew you wouldnt ruin a walbro by running it at 9v.

 

[Justin]

I think this is one of the most debated about topics on the boards. The Walbros specs say it'll work just find at 9V.

When the 88T was still around there was a nasty hesitation from idle if I was to floor it... I bypassed the resistor and it went away 100%

That's my input into the issue

 

[QWIKSTRIKE]

hmmm. i must be missing something.

with the stock setup itll kick it over to 12 volts in open loop, and as far as i knew you wouldnt ruin a walbro by running it at 9v.

Maybe, maybe not but the one I had in the tank didnt run half as good as the new ones after a year, and pumped less fuel at the same setting by 5 psi.

 

[lagged]

Maybe, maybe not but the one I had in the tank didnt run half as good as the new ones after a year, and pumped less fuel at the same setting by 5 psi.

i recall seeing a chart some where showing the rate of flow at different voltages.

ah i dunno. i bypassed the resistor anyway a while ago.

 

[QWIKSTRIKE]

i recall seeing a chart some where showing the rate of flow at different voltages.

ah i dunno. i bypassed the resistor anyway a while ago.

I am no expertmaybemy FPR wasgoing bad!

 

[robbo185]

i run mine at 9v...no problems for me

 

[jtamulis]

I don't sell walbros on my site because they are junk.

If you can hear a walbro fuel pump, it is already bad.

Jeff

 

[robbo185]

I don't sell walbros on my site because they are junk.

If you can hear a walbro fuel pump, it is already bad.

Jeff

hear all the time or just at wot?

 

[jtamulis]

If you can hear the pump soundly at idle, it's bad.

when you put your blinkers on, at idle, and can hear the pump

wee woo wee woo wee woo

It's bad.

Jeff

 

[lagged]

maybe if you hear the sound change and fluctuate with an electrical load on the system its bad, but every walbro pump brand new ive seen installed, 2 in friends cars and one in mine, also make the same sound while they are running.

hearing a walbro dosnt mean its bad, that is normal.

the only way to test if it is bad is to see how much current it is pulling, or to measure how much fuel it is flowing.

if it makes a significantly different sound than what is normal, then something might be wrong and you should test it.

again, just cause you can hear it does NOT mean it is bad.

3 out of 3, brand new pumps all have made the same sound while running, and none of them have gone bad.

 

[jtamulis]

a LOUD walbro is bad. A normal one is not bad. If its really really loud it will
not pump high pressure and volume.

Jeff

 

[lagged]

a LOUD walbro is bad. A normal one is not bad. If its really really loud it will
not pump high pressure and volume.

Jeff

id tend to agree.

i just wanted to clarify for those who might have been mislead, if you can hear the fuel pump, it does NOT necessarily mean it is bad.

 

[QWIKSTRIKE]

I don't sell walbros on my site because they are junk.

If you can hear a walbro fuel pump, it is already bad.

Jeff

Who do you use.

 

[figgie]

Who do you use.

Weldon!!!

 

[QWIKSTRIKE]

Weldon!!!

Damn I was gonna get one of those.Or shall I say 2 of those

 

[figgie]

Damn I was gonna get one of those.Or shall I say 2 of those

2 Weldons?

You sure about that as the 2025 @ 45 psi flows as much as two walbro at 0 psi

 

[cruzian7m]

would i need to perform the 12 volt mod with the mr2 alternator upgrade and a standalone? I've got the walboro pump and a haltech standalone which controls my fuel pump. (p.s.- the car is down for the winter).

 

[QWIKSTRIKE]

would i need to perform the 12 volt mod with the mr2 alternator upgrade and a standalone? I've got the walboro pump and a haltech standalone which controls my fuel pump. (p.s.- the car is down for the winter).

Basicly this has nothing to the alternator, andlots todowith the fuel pressure regulator!