1993 Mazda b2300 • 4 cylinder 2WD Manual • 139,000 miles

1993 mazda b2300 p/u with a 4 cyl the engine starts up idles fine but when you put it in first gear and step-on the peddle it wont accelarate properly like when the peddle is stomped to the ground it just bogs down and does'nt pic up speed what could it be, ( tps, idle valve, maf?) This might help< when the engine is in neutral and I manually apply the throttle at the throttle body (hold open) then the engine rpm go up and down, up and down with the throttle held in one posistion say 3/4 open.4 cyl engine with plugs on both sides, two coils
December 22, 2010.

Check the fuel pressure and MAF. These are the most likely fault. Check for vacuum leeakages between MAF and throttle body.

Have you tried to retrieve for trouble codes?

Dec 26, 2010.