cylinder drop on 1990 Mazda B2600

truck was running fine,now cylinders 2 and 4 will not fire.
I have good spark on both cylinders. Engine will run,but I
can remove plug wires and engine sound the same.apparently
I'm not getting fuel to those cylinders.Yes,the engine is fuel injected,it is the 2.6L I.

Asked by for the 1990 Mazda B2600
3 answers
help--mine is doing exactly the same thing--did you get to the problems--thanks a bunch--was told yesterday that computer is bad and causung problems
I had the same problem which I corrected by having the ECU rebuilt by AVProECM.
http://www.avproecm.com/mazda.htm
Look into this problem on other forums. You'll see that this is quite common and the repair is very effective. Costs about $200.
DID U HAVE A TUNE UP DURING THE TIME BETWENE UR PROBLEMS ?