My 1990 300e idles a bit low and rough. Especially when warm. Also it sometimes takes two or three attempts to start. Lots of things to check out, I know, but anyway today I decided to do the injector seals. Very cheap and potentially helpful.

Basically it is an easy job. It's good to have a ball-end hex key for the holders. Like this


And a semi-closed 14mm wrench for the fuel lines:


Remove the air filter box and loosen the cable canal to get access

Use a 17mm wrench to counter hold the holder and release the fuel line. I did not release the fuel lines from the distributor.

Injectors out


I was absolutely not able to slide the old seals off. Tight fit. I simply broke them to pieces. Wise grip locking pliers is handy.

At first I didn't realize that the plastic sylinders going down in the manifold can come loose too. Just pull them out. Fitted o-rings to them and refitted. (Was much quicker the second time in the same day... - see below. Thanks duxte1!)


The injector 3 and 4 is a bit of a hassle to reach but apart from that it is smooth sailing.

Anyway - car started - difference was ... Subtle. At least I know these parts are ok now. Should probably have the injectors inspected and/or replaced too. Later