Why would a 1987 Mazda B2200 pickup start up run for about 4-5 minutes then shut off It will do this and not continue to run.?

Answer 1

Check the fuel filter 1st if very old change it out.2nd I would remove the egr and clean with carb cleaner or brake clean and make sure the metal pintal moves freely (use a flat head screwdriver to do this) and using sand paper or wire brush is a good idea.Another issue is the collector mounted below the exhaust manifold is it is blocked up with carbon u should remove it and u do have to pull the exh man off to do so.To clean use some muractic acid and let soak for a while (use care when using this!!) or brake cleaner will work and reinstall.Now if the catalytic convertor is old u may want to replace it and a simple feel from the exhaust tail pipe being weak is a sign that it's not alloying the exhaust flow and choking the engine.If u do the above and no change do a tune up plugs,wires,cap/rotor.I could list tons more but the egr is typically what causes these trucks to choke and cut out based on my 22 yrs of owning mine since I bought it new.