i'm working on a car that's running very rich at idle and stoich at regular cruising speeds. but if you give it gas or are at wot, it's showing to be running very lean. what are the different possible reasons? here's short list of the parts on the vehicle that may be the culprit.

ls/vtec
p28 w/jun program
walbro 255
obd0 b16a injectors

the fuel filter is brand new. so i know that is not the issue. it wasn't doing this before but is now all of a sudden. could it be an o2 sensor, bad injector?

any ideas are appreciated.

 

How lean and rich is it running? What does the wideband show?

Are b16 injectors correct for an lsvtec? I'm asking because I don't know and it seems too small. Wouldn't you want at least gsr injectors? Hell they could be the same cc as far as I know.

Anyway, the problem is probably just in the program.

 

i would not know about the injectors. i assumed that all b series vtec injectors sprayed the same.

 

anyone?

 

most liekly it is the "jun" program.
tune it so the fuel demands are being met properly.

 

ok, so the program can just go bad all of a sudden? reason i ask is because the same ecu was used on my last motor without any issues.

 

so it worked on yoyr last engine, but this is a new engine is it not?

 

have you pulled the plugs? you can check if you have a cylinder that is leaning out, also, it may be just an issue of tuning it.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by v4lu3s &raquo;</TD></TR><TR><TD CLASS="quote">so it worked on yoyr last engine, but this is a new engine is it not? </TD></TR></TABLE>

yes, completely different motor.

 

i'll pull the plugs again and do another compression check, if need be.

 

jun chip and a walboro 255. thats your issue. do you have a adjustable fpr if you do adjust if not its time to get one becaue that pump will simply (sometimes) overpower the fpr. it sound like too much fuel pressure at idle check the fuel pressure and you will most likly see your answer.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by vtecb20coupe &raquo;</TD></TR><TR><TD CLASS="quote">yes, completely different motor.</TD></TR></TABLE>

i personally would not expect one program to work on every engine.
i have an h22 program that i made for acustoemr who was able to run a 13.3 in the 1/4 mile, but for me its way too lean up top. for a friend of mine its not even possible to drive with it. when i switched my program up i saw a .4 second gain at the track...and we all have h22's with bolt ons.

 

so..what are the wideband readings?
all those ''jun,etc'' fuel maps are usually way rich for most applications; timing could be an issue, but then again most of those generic chips use stock timing.

 

yes, there is a fpr on there. unfortunately, the pressure has been pegged at like 48 psi. i was thinking of swapping fuel pumps to see if that helps the issue.