Hey my buddy just bought a 92 civic hatch with a jdm b16 that is turbo and sometimes when he is driving its awesome but after awhile it starts to run really lean like not even on the gauge lean. He can drive for a coulple hours then shut it off and when he goes to start it up its running really lean then too.... The guy who had this car before really hacked this thing up. there is an inline fuel pump right before the fuel rail and the wires dont seem to be hooked up. Could that be a problem with him runnin lean?

 

more details on the setup would help. what engine management is he using? how do you know its running lean? is he reading it from a wideband o2 sensor or what?

 

all he has is an fmu right now and he is reading it off of and air/fuel ratio off of any old o2 sensor.

 

(air/fuel ratio gauge)

 

FMU + inline pump that's not hooked up = BOOM.

YES that's why he's running lean. hook up that inline pump ASAP before he blows the motor.

 

Could we just pull that inline pump off and run the line back to the fuel rail becuase he is not running any more than 5psi?

The guy before him may have run more boost than that which is why he had the inline pump in and just unplugged it when he turned the boost down to sell the car?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 93civciv &raquo;</TD></TR><TR><TD CLASS="quote">(air/fuel ratio gauge)</TD></TR></TABLE>

So a narrowband?

 

Come again?

 

I do not know to much about the wideband or narrow band 02 sensors so i dont know.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by notoriousB &raquo;</TD></TR><TR><TD CLASS="quote">FMU + inline pump that's not hooked up = BOOM.

YES that's why he's running lean. hook up that inline pump ASAP before he blows the motor.
</TD></TR></TABLE>

Yeah, what he said. That is obviously one of the problems and quite possibly "the problem."

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 93civciv &raquo;</TD></TR><TR><TD CLASS="quote">Could we just pull that inline pump off and run the line back to the fuel rail becuase he is not running any more than 5psi?

The guy before him may have run more boost than that which is why he had the inline pump in and just unplugged it when he turned the boost down to sell the car?</TD></TR></TABLE>
no. how would that possibly help your lean condition?

even <u>with</u> an inline pump anything over 7 psi is pushing it on an FMU.

 

correct, anything over 7psi means something like 90psi in your fuel line, when it should be about 40psi or maybe 50psi.

about that 'lean' word, that narrowband (what you called a/f ratio) gauge is really not telling you much, you need a wideband gauge like PLX M-300 to say anything about the actual a/f ratio.