Black smoke in reverse (1 Viewer)

[wolf den]

My LJ 78 emits thick black smoke occasionally only in reverse, Im having a difficult time finding out what the problem is and the "paper clip" diagnostics is not helping.

Has anybody here experienced this? If so what was the cause?

Many thanks in advance....

 

[roscoFJ73]

My LJ 78 emits thick black smoke occasionally only in reverse, Im having a difficult time finding out what the problem is and the "paper clip" diagnostics is not helping.

Has anybody here experienced this? If so what was the cause?

Many thanks in advance....

Have you let some else try forwarding and reversing while you watch from behind to see if it really is worse?

I cant see too many valid reasons for smoke being worse in reverse unless momentum is causing something to block the air intake.

Otherwise ,the fuel is highly pressurised when it is sprayed into the cylinders and movement of the vehicle would have little effect IMO