My 86 240 DL standard tranny requires the engine to be at high rpm's or it quits. If I let the rpm's down it is almost impossible to get them back up while engaging the clutch. There is an occasional backfire. I just changed the heater motor and thought I was careful with wiring. It ran fine for a few days after finishing with the heater motor, and then one morning decided it was not going to run worth a darn. The timing was done 4 months ago and it has new plugs, rotor and dist cap. Other work done includes a new in tank pump and a used main pump about two years ago. The vacuum lines seem OK. I checked all the grounds I could find. Not quite sure what to do next and any thoughts would be much appreciated.
Rene

 

is it the tranny slipping or does the engin just not have enough tokeep the car running?

 

Is the clutch cable adjusted properly?

 

Sorry for the tardy reply. It was time for an infrequent visit to the volvo specialist. The problem turned out to be the air mass sensor. The engine simply wanted to quit unless I kept the revs uncomfortably high...if I shifted into third the engine wanted to die. I am told the bad air mass sensor was shutting off or sending wrong signals for the fuel supply. I am happy to be up and running again. Thank you everyone for your interest.
Rene

 

Glad you got it fixed.