Just started a Mazda B2200/91 truck that had sat for 4 years. Had to drop the fuel tank and replace fuel pump and did the usual battery,oil,filter,air filter and it started but rough. Will be changing the coolant what else would you recommend as I get this thing road worthy ?
Coolant flush is a good idea. If it were my car, I would also change the oil then change it again a week later (after running the car a few times). You shoudl also check all of the brakes too- sometimes rotors and stuff can rust, and you might want to check the fluid too. Check your air cleaner to make sure that no rodents made their home in there.
Check the condition of the tires, if they are old there might be some cracking in the sidewall.
I would stay away from the motor flush . . . just drive it a bit and change the oil in 500 miles, then again at 1000. This will certainly clean out the motor, but not all at once, and give the filter(s) a chance to catch the crud. The motor flush might cause more problems than you want. Change the brake fluid, the old stuff probably absorbed some water. Look over the brakes and exhaust. Look at the suspension while you’re down there. A new gas filter would help. Maybe new plugs . . . or at least clean the old ones and re-gap them, as well as the cap and rotor. All of these suggestions are easy and will cost you very little $$, but will put you in touch with the truck as you work on it. Kinda fun. I started a '79 Dodge pickup with a slant-6 that sat for a few years, ran better every time I drove it, did a little bit here and there, now it starts on the first crank, runs great. Good luck! Rocketman