Hello,

As the title says, I have a 500SEL with some running problems. At 151,xxx mi, it's been sitting for 4 or 5 years due to a developed running issue. Garaged in the dry desert climate of Southern California. Symptoms like rough idle and stalling at random times while driving point to a vaccum leak, however investigation may prove otherwise.

I have a shortlist of things to go over on labor day weekend, but I wanted to post up here in hopes that a second opinion may guide me directly to the problem. Has anyone else had these issues on the 5.0L engine and have a solution?

Bonus photos for reading this and helping me out. Your input is appreciated! I can't wait to have this thing running like a champ again.

Bump, any ideas?

I would start with

1) Drain the gas tank and put new gas in it.
2) Check the Fuel Pump and change the Fuel Filter
3) Get the injectors checked and cleaned - Replace as need.
4) Check the Fuel distributor and Warm up regulator
5) Then Spark plugs etc.

Good luck

​​​​​​Get all the info you can about the Bosch Jetronic injection system. The plenum and pintel adjustment may need to be cleaned and serviced. When this system is working properly and adjusted correctly these cars are phenomenal. Good luck.