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Will AMM damage ECU???? 700 1991

posted by  someone claiming to be ibs740 on  Wed Feb 25 06:10 CST 2009 [RELATED]

Hi,

My 91 740 turbo wagon has been acting weird for a bit. I had a bad ECU (High HC @ idle) during an emmissions test. Swapped the ECU for a spare & the oxygen sensor & it passed. The oxygen sensor wasn't sweeping btwn 0.1-0.9 VDC. Just kind of hovered around 0.5 VDC. I actually think the sensor I swapped is OK.
I have my Programa ECU back in now & problems continue. Persistant Lambda trim errors. I've had both errors lean & rich.
Problems are high idle (1400rpm), popping exhaust @ idle, poor gas mileage.
Starts & runs OK. Does a tiny diesel when the ignition is turned off (rich).
Did the FAQ AMM test & tests OK. Runs real bad if disconnected.
I have finally found my intermitant vacuum leak. # 3 intake runner. It finally leaked long enough to find. Water spray worked great to find leak. Will fix this weekend.

My question is can a bad AMM cause damage to the hybrid circuit or other parts of the ECU?






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