zima;

I pretty much went through the same routine you are experiencing with my 1986 240DL. You may want to check the following: 1) air intake bellow hose connecting air filter with AMM (remove and inspect for any small holes - replace with a Genuine Volvo hose only if holes are found, the aftermarket is junk) (mine had holes and the car ran much better after hose replacement); 2) replace intake manifold and TB gaskets if you haven't already; 3) check and replace the air box thermostat - it can fry your AMM if broken; 4) check engine grounds and sand contacts to ensure good contacts; and 5) verify throttle plate is closing completely after cleaning - sometimes the TB is misadjusted to function in a dirty condition. I repalce both my engine and ignition harnesses. If you have the deteriorating wire insulation problems, do it. Consider replacing the ignition coil, if showing external casing wear. Hope this helps.

Rustydog
1986 240DL
151k