Had to replace the computer and TSP on my 1989 2240DL, Jetronic 2.4. Surging then really high idle.
1. Throttle linkage - should it be adjusted to put no pressure on the throttle valve arm or some downward pressure?
2. TPS - How much movement of the throttle valve arm should there be before the "click"?
3. Sometimes when letting off the throttle the car has a fast idle, sometimes normal idle. Tried it with the throttle likage disconnected from the throttle valve arm, same results. Cleaned the throttle valve with spray. Should I remove it and clean/rebuild it? Might be bindking sometimes? Are there rebuild kits?

I THINK I GOT ALL OF THIS FIGURED OUT. I HAD TO REPLACE MY MAIN JETRONICS COMPUTER WITH A JUNK YARD VERSION OF THE SAME NUMBER. CAR STILL IDLES FAST HALF OF THE TIME. IT IS THE AIR BYPASS VALVE SYSTEM. I HAVE A NEW POST TRYING TO FIND OUT WHAT THE BLACK BOX ABOVE THE PASSENGER'S FEET ON THE FRONT WALL DOES. MY HAYNES MANUAL LACKS A BIT HERE.