83 Mitsub L300 ?'s

Next time it happens, pull over and check the glass level meter on the carbi, sounds like fuel starvation to me. Maybe the fuel cap is blocked, and when the vacuum builds up in the tank from the fuel usage, it starves enough to run lean and backfire.
Is it a blue L300 by chance (bought from NSW)
Sounds like my old bus! If so, the electronic ignition is from a later model 2 litre motor. (1986)
Andrewwheredayathinkwer mike?

Wizzard,

I have just had a similar drama with my hilux diesel - may or may not be relevant but anyway this is what was happening.

If i drove for 60 ks or so i would have a loss of power then engine stall intermitently. Would get out and prime the fuel filter and all went OK, replaced the fuel filter thinking partial blockage, same problem still occured. Note the fuel tank was swapped over by an associate prior to my buying it he wanted the long range tank and changed it for his standard 66l tank. Anyway Dropped the fuel tank and cleaned it out, found a reasonable amount of like a carbon residue which I believe was from the cheap ass fuel this guy was buying, it was enviro diesel or something. Anyway turned out their was a fine mesh filter on the end of the fuel pick up in the tank which as I went along sucking up the fuel was getting gunked up with the carbon residue in the tank and presto stall, stop the fuel pump all the gunk falls back to the bottom of the tank engine restarts and away you go for another 60-100k. Cleaned the mesh filter and the tank, put it all back together and no dramas ever since.

Note: I did this within about a 1000k of buying the hilux so fortunatly the gunky tank had only been fitted for a very short time as the tank change was done a week before i bought it. Was one of our company utes........

Anyway hope that helps - worked for me. Not sure if the petrol would have a similar mesh filter in the tank.

had the same problem with a bluebird car turned out to be a primary fuel filter at the rear of the vehicle that had not been changed for years.even the dealer who sold it missed it

Wizzard.
The distributer in your L300 runs very hot because of the position under the seat, the electronics in the disy develop an internitant conection, the only solution is to get another distributer. Some have been replaced with later models from lancers or you can go back to pionts. The best distributer is the late model Sigma but your nead a very bright auto elec to change the wiring and drive to suit the bosch sigma unit.
Eric.