power loss on 850 station

Hello friends,
My baby is not running like she normally does. The engine is shaking
especially with low revs, and it's much slower in acceleration. It's
recently had a lot of maintenence including new spark plugs, air
filter, distributor, but not the spark plug cables, could this be the
problem?
The car runs on LPG but the problem pertains also with petrol.
Any ideas anyone?
greetings
TL

 

It's possible a spark plug cable has failed, but I think it's more likely
the firing order is messed up. Double check that the plug wires are in the
correct order around the distributor.

 

Thanx James for your reaction.
I'm going for the failed plug cable, I can't see how it's possible
that the order of the plug wires could just suddenly change like that
on the distributor.

 

That is easy. When they changed the plugs they could easily switch two
spark plug wires. That is an easy mistake to make. It is even easier
to do when changing the distributor cap. Another one is to mess up the
timing when installing the new distributor.

 

Well guys, I renewed the plug cables this morning and my baby is
purring again. Thanx for your feedback. TL