My 86 E320 exhibited stalling on start up which seemed to go away as long as I gave it enough accelerator to keep the rpm's up and it also ran fine around town unless I was stopped. However, on the freeway it went into limp mode a couple of times - which is very definitely not a safe thing to have happen.

After a thorough search of the forum, I found numerous possible causes but the culprit was the VOLTAGE REGULATOR. Easy to check, just put a meter on the battery with the engine running. You should have less than 15 volts. Mine was putting over 18 volts at idle which was causing havoc with the sensitive electronics.

It is located on the alternator and not expensive to replace.

__________________
'76 240D-Sold
'78 240D-Sold
'85 300 SD, 165K-Sold
'88 300 TE, 165K-Sold
'64 Porsche 356C Cabriolet- under restoration
'86 560SL 124K Miles-Sold
'94 320E Wagon, 74K Miles-128K Miles JUNKED
'06 E350 Wagon, 84K Miles
07 SL550, 14K Miles

Wow.... problem, diagnosis and solution all in one quick post.
Thanks

__________________
1985 300D 198K sold
1982 300D 202K
1989 300E 125K
1992 940T

"If you dont have time to do it safely, you dont have time to do it"

"The democracy will cease to exist when you take away from those who are willing to work and give to those who would not."