i got a 90 crx si, isnt the capacity 11.9 gal? i jus filled up today from being empty empty, like the car cut off, and i only got 8.8 gal in, even with me topping off. is this normal? i know from my other crx that i could usually put in 9.3-9.5 gal when the gauge was below empty but the car never stalled out on me.

also, i jus put in a 190lph walbro fuel pump...would this affect gas mileage at all?

thanks

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by rasta420 &raquo;</TD></TR><TR><TD CLASS="quote">

also, i jus put in a 190lph walbro fuel pump...would this affect gas mileage at all?

thanks</TD></TR></TABLE>

Yeah higher volume pumps will tend to make you run rich (more fuel/burn = less mpg)...even though your psi is the same, the pumps will get more fuel through. Check your spark plugs and see how black they are on the base. If you remember what your plugs looked like before you installed the pump i'll bet they are darker.

If you have a fuel pressure regulator turn it down a few psi.

Vince

 

Heh... my 255 is killing gas mileage.... anyone know off the top of their head the stock fuel pressure for a 91 civic si? (d16a6)

 

note to self! get FPR before installing the walbro 255.....

 

I'm at about 45psi with vacuum hose on btw. Just as a reference for people.

And it'll be boosted soon and wideband tuned. So not worried much about the higher psi. Just sucks for the week/2 that I drive it as is

 

from what i have read on uberdata forum a high volume fuel pump rasies fp from 42 stock to about 55. Just something to think about.

 

Yes, stock is supposed to be 11.9gal on the Si/DX.

Put consumption from the bigger pump asside for a moment, isn't he saying that it was cutting out/starving and he ended up physically putting less in (8.8gal)?
Meaning the gas wasn't used up, there's ~3 gallons remaining in the tank...

I forget how those Walbro's install exactly, but could you have somehow shortened the overall length of the pump/pickup assembly? So the pickup is not at the bottom of the tank anymore and you don't scavenge the last 3 gallons?


On another point the gauge could be off, I've heard it vary from car to car. So your gauge reference might be off. But then that wouldn't explain if you were truly starving.

 

yeah i can only put 7.4 gal in my tank

 

I have the same problem except less severe. At about 1 to 1.5 gallons, my car will bog like crazy if I try to accelerate. This seems to be endemic to this type of car and fuel pump because everyone that has a swap motor has had to replace the fuel pump.

Since I've changed my fuel pump, I have had no noticeable change in gas milage.

 

in my Hf i have rarely hit the 9 gal mark...on all the way dry.....

 

My car usually takes 7.5 to 8 gal . I also read that the tank is 11.9 gal. A couple weeks ago it took 9.5 gallons. I was like wtf. The pump didn't shut off when it got full, there was gas everywhere.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by AgentJam &raquo;</TD></TR><TR><TD CLASS="quote">

Yeah higher volume pumps will tend to make you run rich (more fuel/burn = less mpg)...even though your psi is the same, the pumps will get more fuel through.</TD></TR></TABLE>

When you have a high volume pump the stock fpr will become a restriction because the return orifice is too small. I drilled a 1/32 hole in mine. It dropped 2 psi. I have a walbro 255 running 50 psi wot. 26 miles a gallon.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Zaakro &raquo;</TD></TR><TR><TD CLASS="quote">yeah i can only put 7.4 gal in my tank</TD></TR></TABLE>

I think your gage is slightly off.

A walbro 255 is overkill. You can expect to gain 8-10 psi of fuel pressure just from the pump. After your lower the pressure you'll run rich at idle.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by julio_bOostamante &raquo;</TD></TR><TR><TD CLASS="quote">note to self! get FPR before installing the walbro 255.....</TD></TR></TABLE>
Anybody try the aem fpr made for hi volume fuel pumps? The b&m doesn't work too good with a walbro 255 at idle.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by eda6 &raquo;</TD></TR><TR><TD CLASS="quote">Anybody try the aem fpr made for hi volume fuel pumps? The b&m doesn't work too good with a walbro 255 at idle.</TD></TR></TABLE>

I'm rockin the AEM fpr with walbro 255...aem gives you 3 orafice's (sp?) for different applications/fuel volumes. I'm running the middle sized and have good adjustability.

Currently i'm running rich at idle but this is with a rough tune on my power fc...in a few weeks i'll have a nice good dyno tuning session to clear everything up