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beepbeep beepbeep is offline
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Join Date: Jun 2001
Location: Sweden
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Originally Posted by Alan L View Post
Goran - can I pick your brains for a couple of questions?
My air plate opening at idle is extremely small - less than 0.5 mm. My problem with the AFRs is that as I move off idle in the 1-3000 rpm range, the AFrs lean off by about 3 numbers from idle AFR, and stay there, until boost fuel hits. So, if my idle AFR is 12, once I am moving I end up with AFR 15, and misfire, lack of power etc. This says the metering piston needs to be higher in the fuel chamber (1/4 turn on mix screw) for this air plate opening. If i make my idle pig rich (10) I can get down to 13 AFR at around 2000 rpm, and it begins to respond to throttle.
So, possibly the idle air plate setting is wrong? What if I knocked the air plate down a fraction - this would lean my idle AFR off, and have less effect on intermediate openings AFR?
Maybe my airplate is just set too high? I cannot go any higher - it won't lift any further than its current rest position.
Or will my piston just compensate for any air plate adjustment. I think this adjustment is independant of piston setting?
Second Q. My WUR system has another complicating piece stuck between WUR and fuel head. From previous discussion on this forum the conclusion was it is a fuel enrichment device (Bosch) that is normally found on Mercedes. A small chamber which my WUR feeds into and exits to the fuel head. I can only conclude it is some sort of diaphragm ballast thing that allows temporary softening of WUR pressure. I would dispense with it - but I need another WUR fuel line to do so. It has an adjust screw in the base of it - but all I can feel is nothing, until it comes up hard against the internals. Any experience of this? Maybe I should fiddle with that screw?
Thank you for your time.
Hmm. Honestly, I don't know much about CIS. But yes, your door might be sitting offset to cone and whole cone VE "mapping" is thus shifted.

There is a small entry in manual which says that flapper can be forefully adjusted if it sits too high.

I would start with bypassing the Mercedes device. I suspect it contains some sort of spring. Maybe accelleration enrichment device?

After that is done, try shifting the flapper so you get more gas off-boost and then adjust down idle CO with usual Allen wrench.

Thank you for your time,
Old 07-28-2008, 04:42 PM
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