Hi guys, been a few years since I've been active on here since I sold my last 300d. Recently acquired a 1985 500sel on trade from a guy here locally and I'm trying to figure out a few issues with it. Mainly the hard starting issue when cold. On a stone cold engine the car will fire and then stumble and run rough with an idle around 400rpm. If it doesnt stall it will idle extremely rough for approximately 15 seconds and then idle picks up to a normal level and all is great. If its say below 50 outside then usually it will stall and continue to stall unless I shoot a little fuel through the airflow meter until the idle picks up.
I have replaced the injector seals, injector holder o rings, air distribution tubes and y tube from the idle air valve to the distribution tubes. I've read some suggestions on looking at the ovp but for the life of me I can not find it on this car. According to everything I've found searching it should be in location I in the fuse box but there is no socket for a relay to plug into. I also cannot find anything on the firewall as I've seen that it's there on other years. Any ideas with either of these issues? Thanks in advance!

all u.s market 126s have that relay next to the fuel pump and klima relays. is it missing? is it euro instead?

Sorry I should have specified it is a euro spec car!

post your vin. i can find out if it's there.

btw, my brother lives in bealeton. we came out of fairfax, i just got further.

VIN is WDB126037-1A-081540. I'm in like the brandy station area so not far at all!

epc does not show the ovp relay for a 126-037. i've only worked on 1 gray 126 and that was 20 yrs ago.

was it certified for us import? did they install something to control mixture? should be an o2 sensor added on.