3/4's of a tune-up = rough idle/stall pics included
 

Had a problem with rough idle/stall. And I mean a bad problem,,, (new car to me) PO said prol needs a ICV or a Fuel Press reg.

Did the usual, inspect plug on cylinder one - new Bosch platinum.
Checked for vac leaks, fiddled with Air hoses (going to icv), noticed crack one, so replaced them. tested icv. ,,,

well reading threads I found out that plat plugs are a no-no on the 2.3 190e's. So I pull out the ratchet and start removing the plugs. 1, 2, 3 no prob,,, get to number 4 and all my might All I got was a ughhh. 1 ratchet click. Did this again several times,,, decided to look for the 3/8-1/2 adapter, which was nowhere to be found,,, Went back to the number four spark plug after 3 or 4 breathers, I finally got it out. Hey it's NOT a bosch platinum, but a bosch copper with about a .60/1000 gap!!!

I haven't gotten to starting the engine yet as I awaiting parts to put everything back together,,, but I'm willing to bet that when it does go back together, I'll have a good running 190e.

Pictures below.

Years ago we used to get 283 Chevies in for tune-ups and 9 out of 10 would all still have the original #8 plug b/c they were so hard to get out [ due to steering box location] that the last guy just skipped that one..That's what happened to yours ..it was ready to snap or strip, the guy didn't want to take that chance , so he left it in..but then he also went ahead and used the wrong plug to boot...he's a good wrench.
Use Bosch Supers , or better yet, NGKs

glad you found it been there done that.

So,,, off to napa for a 14 mm spark plug thread chaser,,, in twice with the chaser,,, put a new plug in,,, now I gotta wait for the little rubber piece from MB dealer that goes into the fuel press, reg (broke it off earlier)