This may sound like an elementary question, but here goes.

I was thinking about getting a Walbro 255lph fuel pump in the hopes to richen my car up a bit. Those of you who know me, know that I have been having fuel issues for some time now.

Will simply installing the Walbro, everything else the same ( SFMU w/2.72 ring/disk, Hahn inline, 415cc's etc. ) richen up the mix? Or do I have to mess around with everything? I realize that to get optimum performance I WILL have to tune etc but right now I am just interested in richening the basic fuel map.

I also hope to cure my double prime-double crank, start-up procedure that I have to currently go through. I keep killing starters doing it!!! DRIVING ME MAD!!!...and broke.

So fire away! Any help is welcome and appreciated.

I don't think that it would richen up the overall map unless you are already exceeding the capabilities of your current fuel set up (which is entirely possible)

You'll be able to pump more fuel easily with very little stress on the fuel pump, but where can it go when the sfmu and injectors regulate the rich/lean mixture? The inline and stock pump is more than enough. If you're too lean, then it's your injectors if not your sfmu.

it very well could richen you up a bit if your injectors are gettign starved for fuel...

if your throw ina walbarro pump ona stock 420a it runs rich as hell.

Originally posted by DSMRoadster
You'll be able to pump more fuel easily with very little stress on the fuel pump, but where can it go when the sfmu and injectors regulate the rich/lean mixture? The inline and stock pump is more than enough. If you're too lean, then it's your injectors if not your sfmu.

I understand what you are saying, but Motofool for example says that if you simply throw the walboro on a stock Eclipse, it will run rich as hell.

This is exactly my predicament. Two conflicting answers. I am thinking that its NOT my injectors because a.) they are new, and b.)with my SFMU ring and disk combo, and slightly larger injectors, siueclipse is running MUCH better hp numbers and not leaning out at all. And he has the 20G. I have only run 14 psi and I would think that the 415cc injectors should be able to flow more than what they appear to be according to my A/F ratio.

Unless...possibly HRC sent me the wrong size ( smaller injectors than I ordered ). I think that is far fetched tho.

My other reason for the new fuel pump idea is because I have to double-prime my inline and crank the car twice before it starts. Which leads me to believe that I am not getting enough fuel the first crank.

Thanks for the help so far. Please keep the suggestions/thoughts coming.

I HATE MY CAR!

I'm thinking you may have an issue with your inline pump or your intank pump. Adding the walboro won't give you any more fuel, unless you are running mad insane fuel pressures. But you never know, the stock intank may be holding you back as far as flow goes, but its unlikely. The only thing you will gain by adding the walboro intank is that its going to feed the inline pump faster, and quiet it down. The only hypothetical situation I can think of, is if your inline pump is starving of fuel at higher pressures, because the stock pump can't keep up. I really don't think thats the issue though, but ya know :) Having to double prime to start makes me think something is not right somewhere..do you know what your fuel pressure is at 14psi boost? What is your A/F ratio?

Not sure what my FP was at 14 psi. My FP guage broke and I dont think that it read correctly being that I didnt know that I was suppossed to remove the Schraeder valve. ( it mounted on the fuel rail test port ) However when I took the car to the dyno here where I live, the best they could get my A/F ratio to was like 16:1 or something around that. Better than the 18:1 I was running at the Shootout, but nowhere near enough!

Originally posted by 95greenhrcgs
Not sure what my FP was at 14 psi. My FP guage broke and I dont think that it read correctly being that I didnt know that I was suppossed to remove the Schraeder valve. ( it mounted on the fuel rail test port ) However when I took the car to the dyno here where I live, the best they could get my A/F ratio to was like 16:1 or something around that. Better than the 18:1 I was running at the Shootout, but nowhere near enough!

Holy crap, 16:1?? at 14psi?? That is WAY to lean. Actually, dangerously lean. Even a NA motor at WOT needs around 14.7:1 A/F..I would not even think about boosting, without a good fuel pressure gauge. That may tell the whole story right there. Its got to be one or more of 3 things, at least to start with:

1- stock fuel pump
2-inline fuel pump
3- malfunctioning SFMU

You prob have an issue with one or more of these things. Get that fuel pressure gauage ASAP!!! At 14 psi, you want to run an A/F *around* 13.5:1 -- 13.8:1 I'm willing to bet is an issue with the inline pump or the SFMU..

If it is the inline, would the 255lph Walbro supply enough fuel without it?

BTW how could I tell if its the SFMU?

Jon, you can't tell anything right now. Without a working FP gauge you have no idea what your static FP is to begin with or what your actual rise rate or WOT FP is. There very well could be no malfunctioning components in your fuel system. You just can't tell what anything is really set at. But here is a something you can check without assuming something is bad. Do the fuel pump rewire mod if it has not already been done. And also I remember at the shootout something about your stock 95 regulator not being disabled, I don't know if it's still the case but it's got to go. Anyways, I hope you get it all worked out.

I guess I should get a new FP gauge. Is mounting it in the fuel rail a good thing or should I mount it somewhere else. Removing the Schraeder valve is necessary too isnt it?

Avenger....I did do the FPR disable that was listed on Corbin's site right after I got home from the SO. I was able to get the FP down to about 23-25 psi at idle.

For your FP gauge, if you have a SFMU just splice into the line from your test port going into your SFMU, your shraeder valve should already be out and there should be a fuel line coming out of there already. Also they are right, if you have a SFMU, adding a walboro won't automatically richen you up without adjusting your SFMU, your fuel pressures will stay the same assuming you aren't maxing out the flow of your current pump (do you have an inline?).

Jon...if you want, I can take at look at your car when I come by to pick up the head this week. You certainly need to remove the schraeder valve if you have anything hooked up to it. I have a schraeder vave tool. You have to buy a new fuel pressure guage. They are only $20...so buy one! Its OK to have it on the rail.

Corbin

'95 ESI-T
HRC+FMIC+ETC...



Gimme fuel...Gimme fire...Gimme that which I desire

Corbin, if you could bring the Schraeder valve removal tool that would be cool. Do you think that we can remove it with the fuel rail in the car?

I will try to take as much stuff off the car as I can if I get some time this week so that we will be able to remove the head a bit faster. If you have any tools, I would suggest you bring them. I do have SOME, but the more tools the better IMO just in case.

I will email you later in the week with my address and time to meet. I MAY have to go into MD this weekend, but that is up in the air. That wont be till later in the afternoon tho, so hopefully we will be able to get the head outta the car. I think we can.

Corbin, if you guys want some help, I'm free all day Saturday after 12 (I can probably be free earlier if needed). I've got tools! :-D And to answer your question, YES, the schrader valve can be taken out with the rail still in teh car. When installing an HRC kit, you do not remove the fuel rail. When you do go to take out the valve, make sure you've depressurized the system as best as you can. There's going to be some fuel that comes out no matter what, but if you don't depressurize it, there's gonna be a WHOLE LOT MORE thatn you want coming out! If you want to give me a call, feel free! Just email me @ Jeremy.Sturm@ssa.gov or Jeremy.Sturm@cox.net and I'll hit you up with my cell! Let me know! :-)

Cheers!