I was going to bleed brakes on neighbors car but it fell thru. So I had mb on ramps so I looked into the intake to see inside. What a mess, black and gook. I removed intake and fuel injection lines to get at intake. Baked on crud and an oily mess. Used locking ling forceps and rags to soak up and clean intake. What a mess. Finally after an hour I could see the aluminum intake. Cleaned the gunk on the butterfly, very baked on. I did not think I could ever get it clean. Tooth brush helps, also wrapped in cloth to soak up goop.. Remove spring return on intake to make holding it open easier. used mirror to see bottom of air meter dirty too. Cleaned all parts and hoses. Used silicone grease on rubber parts to keep supple. It now runs very smooth. I highly recommend looking inside intake... LED lights make it easy to see inside... you will get very dirty... 37 years of accumulated crud..