Difference between the 255 and the 190 Walbro fuel pump
 

Hi guys,

Sorry to start a new thread for this but I need to ask if given the same price, would you get the 255 or the 190 Walbro fuel pump? I can get them both at the same price and will use it together with a Walbro FPR...

I am getting it shipped to me at USD169.99, any comments anyone? Thanks in advance!!

The only problem with the 255 seems to be that it overpowers the stock FPR and keeps the fuel pressure at idle too high. This causes trouble trying to get a decent idle. Some have put a bypass line around the FPR before the AFPR to remedy this.

Thanks for the prompt reply Olderguy!!

The 255 will over power the stock FPR, but if I am using an additional Walbro FPR, the 255 should be fine right? If the Walbro FPR is able to drop the fuel pressure...

As long as the Walbro FPR has been installed in place of the OEM FPR and can drop the pressure, you should be fine. If the OEM is left in the circuit, you could have problems.

$169.99!!!!!!!!!!!!!!! JESUS CHRIST!!!!!!!!!!!!!!!!!!! Try This link, you'll be much much more happy.

http://shopping.lightningmotorsports...&cat=24&page=1

yah I know about lightning, but I cannot get a service person online... there is no e-mail also.. I am located in Singapore and its a pain to get online shops to ship and also accept credit card payments... and 169 is together with a walbro FPR..

I have only seen fuel pressure increase by 5 psi at idle with the 255lph HP. The stock ecu is more than capable of maintaining a near stoich mixture at a factory smooth idle.

One of the good guys at M.net tested a 255lph pump on half-a-dozen OEM FPRs and found it overpowered 2/3 of them.

Why take the risk when the 190lph can supply enough fuel for ~350hp at the crank? The 255lph is unnecessary for 98% of folks running Miatas.

I wonder if honda FPRs fit our rail.... I know they are fine with the 255s. Then I could use a B&M FPR also... I'll test it and get back to you guys (on the fitment stuff).

What happens when the 255 overpowers the stock fpr? Does it run like shit or just not idle?

Well, the ECU can handle a couple of extra psi of fuel pressure at idle. The 255lph pumps a lot of times overpower the FPR so much the idle pressure goes from ~35-40psi to ~50-55psi, and the ECU cannot get it to idle of cruise correctly.

Exactly, I don't get this either. There is still so much love for the 255 from the supercharger crew. But haven't you noticed a trend with most supercharger owners and knowing nothing about fueling? I have.

At 50psi of fuel you have enough flow to supply 350BHP with the 190, 480BHP with the 255.

If you are using an FMU, the 190HP provides better flow at higher PSI levels and the 255 drops off eailer.

40-50psi idle with the 255 may cause lumpy idle and rich AFRs.

Its funny you mention this, I just now found out what the dead fuel pump was thats in my car that originally came with the JRSC kit that was on the car when I bought it... I bet you can guess what it was. The 255lph HP version no less. Just a little overkill don't you think?:eek4:

a tad. espeically if a FMU wasn't used.

Yes, although it must be said that the fellow who conducted the FPR tests is a JRSC owner. He's an old-school kinda guy in the same vein as Pop.

i did say most.

hey guys, first post for me!
sorry if this has been covered, but im a little unclear on this and i've read through all the info i could find on here.
if i get a 190 hp walbro, do i also need to get an afpr, or a peirburg..or any of those things? or can i just bolt in the walbro and leave it at that?
i've got a 1.6 but will be using the injectors off the 1.8 NB (230cc i think), and aiming for about 8psi boost (with hopes of a very occasional increase to about 12psi), with a megasquirt.
i was directed here by "aussie driver" as he says you guys know your stuff, and it sure seems so reading through this info. it's great, cheers.

With the 190HP and 1.8's you will need an AFPR to boost your fuel pressure. You should shoot for about 80psi of fuel for 8 psi boost with 1.8 injectors. The difference is that the 190 HP can put out good flow at higher pressures, but you need to restrict the return to tank flow to get the pressure up there.

Read my faq for a little bit more understanding (or tons of consfusion) about the fueling situation. But yes, a FMU be required to raise the fuel pressure in the rail effectivly raising the fueling potential of said injector.

thanks olderguy. so do you think it might be better just to get some bigger injectors and not use an afpr? i have already purchased these injectors but i should be able to send them back and get some bigger ones.
as i said i'm aiming for about 8psi at the moment but would like to eventually get to 12psi boost.
so of the 3 combinations below which do you think is best for that target
1 - 1.8 injectors + 190hp + afpr
2 - bigger injectors (supra?) + 190hp
3 - bigger injectors (supra + 190hp + afpr
4 - something else ? ?