Too Much Fuel Pump?

8111870 · Jul 17, 2010

Hey, i am looking at replacing my stock fuel pump on my 96 GT, and am thinking of throwing in a Walboro 255lph pump in anticipation of future mods.
is this too much pump for my DD? will i have fuel/heat problems during extended drives?
do i need a Fuel Pump Speed Controller? any one running a similar pump NA please chime in.
thanks!

Lee12609 · Jul 17, 2010

i ran the walbro 255 for over a week N/A without a problem, i know a few people that do constantly. if yours is bad and you're certain you will need the walbro eventually do it....

8111870 · Jul 17, 2010

Lee12609 said:
i ran the walbro 255 for over a week N/A without a problem, i know a few people that do constantly. if yours is bad and you're certain you will need the walbro eventually do it....

thanks for the reply.
my short term goals are 320-350 rwhp. maybe running a smaller pump?
i hear a lot being said about the 255 lph pumps and rarely about anything smaller. is there a reason?
thanks again

vtecftw · Jul 17, 2010

return style dumps the "unused" fuel back into the tank...

8111870 · Jul 17, 2010

vtecftw said:
return style dumps the "unused" fuel back into the tank...

yes, and the same fuel gets pumped through the lines and back into the pump over and over again picking up more and more heat each time. im worried that for my daily driver it would cause vapor lock during extended periods of driving.
maybe ill get a 190lph pump and 42lb injectors and call it a day. if i end up needing more fuel one day ill deal with it then.
thanks

Lee12609 · Jul 17, 2010

i wouldnt worry about it unless you frequently drive with low fuel. with the pump submerged the heat isnt much of an issue. infact i've never heard of a problem from this, only heresay online.

you have to realize even a boosted car running a 255lph pump will rarely see boost (maybe once a day for me) so the pump is basically overkill until its in boost.

i'd go for the 255, for the price you cant beat it, i think i paid $99 shipped for mine including the install kit.

331StrokerStang · Jul 17, 2010

Yeah on my DD(SW20 MR2) I run a Wlly and I have never had any problems with it.

Jrgunn5150 · Jul 18, 2010

I run 255 wallys in everything that gets a new pump, including the Saturn

bottlefed97 · Jul 18, 2010

I've daily driven my 2v with a 255 walbro for years and it works perfect.

8111870 · Jul 18, 2010

thanks for all the responses!
youve helped me a lot. i will go for the 255 and 42 lb injectors.
i will update when i start my build, hopefully this winter.
cheers and thanks again!

Jrgunn5150 · Jul 18, 2010

42's are not a good idea, you can have too much injector.

Lee12609 · Jul 18, 2010

yeah, keep the injectors as small as possible, they are easy to swap out later down the road when needed.

8111870 · Jul 18, 2010

i thought the idea was to keep the injector duty cycle as low as possible, ergo bigger injectors
doesnt all the adjustment take place in the tune?
thanks again

Jrgunn5150 · Jul 18, 2010

You're theory is sound but in reality, injectors work in Miliseconds, and they have what's called minimum linear pulse time, the quickest they can operate and be within 2% of their flow rate, below that and the ECU can't operate them quickly enough to maintain proper fueling.

Basically, because the injector is so big, it needs to be open for less time, and the computer can't do it fast enough, whereas with a smaller injector it would be open longer and the ECU would have enough time to send the open/close signals to the injectors.

Lee12609 · Jul 18, 2010

JR is right, i run 42s and have no problem idling at 14.7afr but if you wont have the need for them for a LONG time its pointless to install them now, since its only a 30 minute process to swap them later on. if you do any mods big enough to require that size injector a tune will be needed at the same time so might as well wait.....

basically, less to worry about with smaller injectors.

duff daddy · Jul 18, 2010

255 walbro with 38lb/hr injecotrs.... Ran fine with my last set up, well see how it does on the new set up.

DropTopPony · Jul 18, 2010

Had a 255 in and DD it for several years. I put it in before the blower install and then never did the blower install but the 255LPH is doing just fine in there.

8111870 · Jul 18, 2010

thanks for all the great info!
a wealth of information on this site, thanks all for pointing me in the right direction.
so ill wait on injectors until i get a clear idea of how much fuel i need.
thanks again to everyone
cheers!