Gary2

Let me explain what is happening.

After i do abit of just normal driving the car gradually pulls me extremely LEAN. I have checked out all the fuel components and everything is working great.

In order to get the car out of the lean "mood" all i have to do is reset the ECU and then i am fine for a little while but the car will always pull itself lean. Now i noticed that if i reset the ecu and just drive the car FULL throttle all the time the car wont pull me lean. Its only when i am doing normal driving and try to go full throttle again the car will pull me lean.

Also when the car gets in the lean mood it doesnt not matter how much i increase the fuel on the VAFC or increase the fuel pressure on the FPR the car is still lean. I have even tried plus 50 % on the Vafc and i am still lean.

My fueling setup is 440 injectors, AEM fuel pressure regulator, Walbro 255 intake fuel pump, VAFC II. I have tried New o2 sensors. I also tried running the car without o2 sensor plugged in still same thing. And i tried switching to 315 cc injectors thinking the 440 where to big for the vafc/ecu never helped though

I had a OBD2 reader on my car checking my fuel trims within the ecu and they are where they should be. Long term fuel trim +.01 and Short Term Fuel trim -0.3-+.01 it just fluctuates which is normal from what i read.

I gave my car to a profesional tunning shop they had the car on the dyno for 4 hours and could not figure it out.

If you can give any tips at all it would be greatly appreciated. Thank you!

Gary

rizzoTK

I had a similar problem on my 00 Si when it was s/c'd I found out a little to late that at idle it would read 43 and appeared fine but when i was under boost iwas supposed to go up to about 89 psi and the fuel pump was only pushing a max of 65 psi so the six month old 255 walbro had taken a **** and took my stock ringlands with it. so check fuel pressure under boost with a load. hope this helps

Gary2

the pump appears to be working fine fuel pressure goes up at idle when i rec the car, pull the vcacum line off

DSF

Just out of curiousity, how are you measuring air/fuel?

tub_sephiroth

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by DSF &raquo;</TD></TR><TR><TD CLASS="quote">Just out of curiousity, how are you measuring air/fuel?</TD></TR></TABLE>

I hope you're not relying on autometer's A/F gauge because that thing is just a light show. Lean? Rich? It doesn't matter.

bomber

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

I hope you're not relying on autometer's A/F gauge because that thing is just a light show. Lean? Rich? It doesn't matter.</TD></TR></TABLE>

I was thinking something similar...but I read this part of his post:

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Gary2 &raquo;</TD></TR><TR><TD CLASS="quote">
I gave my car to a profesional tunning shop they had the car on the dyno for 4 hours and could not figure it out.

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

So, that doesn't mean he isn't using autometer, but I sure hope the shop knew better Who knows anymore tho...

Gary2

I have a wideband and egt guage installed.

SOHC_MShue

maybe the hack is your problem. Go obd1 and use uberdata or hondata if you got the money for the obd1 conversion and ecu.

Gary2

I also noticed tonight that my fuel pressure holds fine idle but when i rev it up the fuel pressure rises like it should but if rev up the engine and hold at around 3000 rpms my fuel pressure DROPS lower then what I have it set at on idle.

Mag00n

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by SOHC_MShue &raquo;</TD></TR><TR><TD CLASS="quote">maybe the hack is your problem. Go obd1 and use uberdata or hondata if you got the money for the obd1 conversion and ecu.</TD></TR></TABLE>

Hack runs rich on almost every motor I've ever seen....assuming 440cc injectors or larger...

rizzoTK

sounds like your pump is going out if the pressure drops. had the same problem on jrsc setup, cost me a new engine.

DSF

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Gary2 &raquo;</TD></TR><TR><TD CLASS="quote">I also noticed tonight that my fuel pressure holds fine idle but when i rev it up the fuel pressure rises like it should but if rev up the engine and hold at around 3000 rpms my fuel pressure DROPS lower then what I have it set at on idle.</TD></TR></TABLE>

Might want to check your regulator. I've heard of several instances of bad AEM regulators. Just a thought.