Yeah, I do it too. I've said some truly awful things about my M103 cars that I wish I could take back. I do dearly love all my Benzers! The sig says "for sale" by the M103s only because I want the wife to think I'm trying to do something about the "excess car problem".

Congrats!
Regards, Eric

So, what kind of fuel economy were you seeing prior to fixing the problem? and what about after now? I'm getting between 17.5-19.5 in my m103..

I know the question is for John John but I'm getting about the same 20MPG average from all three of my Benzers in mixed, leadfoot driving. He should be doing a little better as his car should have the 2.87 final drive whereas my two M103s have the 3.07 final drive. On the other hand, he does do that blast up that mountain which would damage his fuel economy.
Regards, Eric

HA :D

Yes, I usually don't drive for economy, for the most part. The weird thing about the ECU and EHA failure, was that gas economy was still good. The last time I calculated mileage was on a trip back from Albuquerque to Denver, which was sometime in late November. I was cruising 80mph the whole way back, and as some may know...that is a good chunk of uphill driving until you get past Pueblo. I averaged 25.5mpg. I imagine if I had been cruising at 75 or even 70, I could have eeked out 26-27mpg.

Once I replaced the ECU, my gas gauge was visibly moving while driving. Very odd combination of part failure IMO. Now that everything is copacetic, I shall do a full tank and calculate mileage. :)

Every time I hear the name Pueblo, I'm reminded of the story my now 77 year old Dad, who grew up east of Pueblo, used to tell us when we were young about how Pueblo got it's name: A long time ago, an old prospector who was on his way to the Rockies and his donkey "Eblo" had set up camp for the night. After dinner, Eblo let loose with a big stinky one. The old prospector said: "Peewww Eblo!"
Regards, Eric

Great Help - 300E Alive!
 

I spent days...sorry weeks trying to get my "new" 1991 300e Sedan to idle properly and start clean.
JohnM, your post really helped even though its 5 years old. Thanks to the other contributors, my car is running correctly again.

I did purchase the new 02 sensor as mine was old, replaced my plugs with Denso non resistor plugs and changed the seals around my injector nozzles. I replaced the ICV hoses, cleaned out my EGR tube (clogged) and changed the bearing on my smog pump. I changed the seal at the base of the fuel distributor, tested and cleaned the injector nozzles and ten connected a MM to 2 and 3 on X11 and got ~.5V (engine idling).
Nice start, smooth idle, no fuel smell in exhaust and I think I'm good to go for emissions.
Thanks again for the AWESOME post.:)
9/30/2015 - Update
Passed emissions. My HCs were very high though. Any thoughts?

10ish years ago I documented what I did in this forum. I know a bit more now and just finished a FD rebuild which I documented here...

https://www.benzworld.org/threads/m103-98-ke-jetronic-inspection-rebuild-recalibrate-including-ezl-and-cruise-control-questions.3079533/#post-18254767