Date:         Mon, 13 Mar 2000 20:30:34 EST
Reply-To:     Wolfvan88@AOL.COM
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Robert Lilley <Wolfvan88@AOL.COM>
Subject:      My exhaust smells good now...What I have learned about tuning
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I have finally passed NC emissions.

It took three attempts.
The first time I had the Fuel pressure at 39 high  @30-32.  I had a fluctuating vacuum. Dirty oil (Forgot to change the oil).
HC 314
CO 1.4
Around town mileage @19-20


Second attempt:
Changed oil to 20w-50, Lowered Fuel pressure to 37 high 29-31 low
Still fluctuating vacumme
Around town increased to @22
HC 315
CO 1.5

Third attempt:
Reduced valve clearence to .00.  vacuum was steady.
Set fuel pressure to 36 high 29 low.
Took throttle body off cleaned.
HC 100
CO .03


What I have learned:

My best mileage has been with the pressure set exactly as Bently states high 36 low 29.
My old stock regulator was high 39 low 32 with my  modified cam: increase duration and lift slightly.

If your pressure is different than stock get an adjustable pressure regulator and set the pressure exactly.  This should maximaze your mileage.


If you have low emmission levels there might be a problem with your FI. I had low levels and had a bad O2 sensor, Idle control module, out of spec Temp II sensor, bad air flow meter.  Yet my engine ran OK.  The power was off...

LESS is better.  I orginally thought that I needed more fuel pressure, BUT my experience proved me wrong.


The computer can only respond so much.
I bought a new idle control module.  When I turned on the AC the engine speed did not increase, but with the correct fuel pressure, it now works.  The computer was ignoring the command to increase the speed because it was already running too rich.

EACH PART of the FI system is important.  While he engine will run, it is will not be at its best, power will be off, mileage will decrease, it runs slightly hotter.  Soon there is a major failure...and another engine bites the dust.

Make sure all the parts are running correctly to increase engine life and decrease frustration.  It might cost some $$ now but better than $$$$ later.




Robert