Cleaning my intake 280sl 79

[peter5888]

Weather ws warm today so i was looking at engine on ramps. Looked inside of fuel injection flapper and shinned a brite light and saw a real mess inside of my intake at the brass colored butterfly. I removed the fuel injection rather easy. The real pita ws cleaning the baked on crud. Took forever. the under side of the flapper was burnt black and chunky. The inner intake was also sticky and a mess. Use long locking tongs to clean up the inside of intake. Till I could see the metal. The sides were a mess too. I even cleaned the underside of the fuel meter plate used a mirror to clean it. Unbelievable amount of crud. What a mess. Probably left over from when i blew the last motor?? DIY take a look in there and if you can clean it up. Used intake cleaner. Scrubbed with a tooth brush for over 1 hour. Loads of gunked rags. Ran a little rough at start up then smoothed right out. Also used silicone grease rubbed into the wires, rubber intake and seals and the cap connections. Re ran the wires to get a better flow. Keeps it all nice and pliable.. Also tightened the power steering belt PITA for sure.. Next the steering and bushings..

[97 SL320]

What you are seeing is mostly oil vapor and a bit of EGR flow. Since the intake is "dry", you don't have fuel vapor flowing through it to keep it clean. As long as the throttle blade and bore are clean, a bit of left over mess down stream isn't an issue.

Keeping the throttle blade and bore clean allows for proper air flow at idle. When air flow is reduced, the idle control is called on to provide more air and sometimes it hits an upper limit resulting in low idle.