Hi, I have a 91 940 with b204E and 214000Km.
the engine misfire, not a lot but misfire.
the head and valves was revised the past summer, and the compression
ratio is very good.
no coolant or oil consumption.
sparkplugs new (original volvo), sparkplug and coil cables is new, coil
new and original, related wirings checked for oxidation, distributor cap
and rotor with few chilometers (miles), rpm sensor new.
air filter OK.
apparently no infiltration of air after the MAF.
the misfires happens when engine run with both gasoline or LPG gas.
I do not know more thing to check...
temperature sensors? MAF?

the power erogation is good.

thanks for aid.