I have have narrowed it down and thanks to steve now have a good number for the eha and duty cycle. My stall is still there but only when the circuit is closed and functioning, although i have to set the duty cycle to about 40% (rich) before I disconnect the system and can drive without stalling. SO now I need to determine the cause. I believe it is the air mass flow. I replaced the potentiometer, but the ohm reading I get is the same with either the new or the old one at just above idle between 3.98and 4.01 k ohm the ammeter loses the continuity then it picks it up at just above 4.02. It is indentical on both potentiometers. Could someone out there with a 560 test this on thier's. I am measuring the 1 and 2 pin from the top. If yours does not do it I have found the problem. Then I just need to figure out how to fix it.
thanks in advance especially to steve for all his patience as i figured out the electronics.
m

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Martin Ingram
Colorado Springs
2005 320 CDI
2006.5 VW Jetta TDI
1991 560SEL (179000 Sold)
1972 280SEL 4.5 ('The Lead Sled' 320000 miles when sold.)
1972 220D (225000 when sold)