Hello, My 1982 XJ6 is having some troubles. At some times, it will start normally and I'll drive. However, after a while the RPM will drop and when I press the accelerator it is hesitant and will backfire a few times and eventually return to a normal operation. On some occasions, upon starting the vehicle, it has low RPM and and when I press the accelerator it'l backfire. Anyone have any insight on the matter?

 

Back firing is normally due to incorrect ignition timing or over fuelling. The fact that it seems to fluctuate may be caused by a failed distributor base plate bearing. Its a long shot but worth checking.

 

You have a lean mixture.

Have the injectors ever been replaced. I would start with their replacement
and at the same time replace the fuel hoses.
It should make a difference in performance.

Walter

 

By "backfire" do you mean coughing up through the intake (often a lean problem or timing) or blasts through the exhaust (often a rich problem).