I have a 1988 240 DL with approx 225000 mi. REcently rebuilt throttle body and am attempting to setup engine to run on spec.
The timing appears to be somewhere between 10 and 20 btdc and since I bpught the car without knpowing when the timing belt was
last changed I am attempting to set timing. The distibutor is not moving when I try to turn it after lossening the lock down nut. Is this usual ? I have even tapped the base with a short pipe and hammer. Is this an indication of a necessity to replace the timing belt ?

(Note : I have inspected the belt and it is not cracked, or worn)

My interest is to improve the vehicle mileage as I have to drive a 100 mi rt daily and after rebuilding the throttle body do not know what is the next step beyond rechecking all the tuneup settings.

Any advice would appreciated.

 

Don't worry about the Dist. Sometimes they will seize. But the computer controls the timing so it won't really help to move it.