I have a 91 Mazda b2600i that acts like its out of time I checked the time with a light and its in time I replaced old fuel and plugs any other suggestions replaced coil and plugs and cap and rotor it is running now sputters and backfires.
You may bneed to run some good fuel injector system cleaner such as BG44K, which you will have to go to a car dealership to get. You will need to run 2 cans.
Here is a diagnsotic walk through for your situation. Just uswe the link below;