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Alan L Alan L is offline
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Join Date: Apr 2006
Location: New Zealand
Posts: 2,809
Leaness happens every time. But once during my CIS test, it suddenly dropped back from AFR 13.5 to around 11 without moving the throttle from the lean spot. It has not done this before - so I suspected the piston sticking. It is still a bit of a long shot, but the clearances are so tight in the fuel bore, and I don't know what level the fuel filters filter down to but particles bigger than a couple of thou would cause binding. There is a very fine screen around the entry ports to the fuel head chamber, and it was completely clean, but even that fine mesh may be too large for some particles. For all I know my tank is full of fine grit. The original head did have scoring on it - which the bosch guy says is dirty fuel.
It is possible my tank has never been cleaned in 25 years , and I don't know the age of the filter. I went to change it routinely when I was originally going over the car - but like a lot of fittings, could not budge the unions, so left it. Went on to other things.
I can't remove the Mercedes bit until I can make a new WUR/fuel head fuel line. It is an integral part of the fuel plumbing. I am stuck with it at the moment. Tried fiddling with the settings on it last nite - adjusting it while engine running and watching AFRs on throttle movement. Didn't seem to have any effect either way.
But I have found a place that can source the appropriate fuel union fittings. Have some on order. Then need to make new fuel line so can bypass the gizmo.
Meantime, pulling tank today/tonite.
Regards
Alan
Old 07-29-2008, 01:50 PM
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