If I'm reading this correctly, the high idle problem started AFTER the ELR connector was plugged in? If that is the case, then unplug it and be happy.

My '87 300TD had a very rough idle when I bought it, I unplugged the ELR connector, manually adjusted the idle to about 800 RPM, and never looked back. That was about ten years ago.

__________________
Respectfully,
/s/
M. Dillon
'87 124.193 (300TD) "White Whale", ~392k miles, 3.5l IP fitted
'95 124.131 (E300) "Sapphire", 380k miles
'73 Balboa 20 "Sanctification"
Charleston SC