engine stutter and stumble when switch gear to drive or reverse

Question

My car starts always at 1200 rpm for the last 5 yrs and never goes down,maybe something wrong with the iacv but the engine never stumble except it started last week,and i got p0302 code. I replaces the injector,distributor cap and rotor, inspect spark plug no.2, i dont think i have leak in the intake manifold,any suggestion? Thanks

Answer 1

Hi there,

Check the plug wire for #2, it may be arcing inside the head where you can't see it causing the misfire. Otherwise it probably is a problem with the intake manifold gasket. A way to tell is with the engine running at idle, spray some carb cleaner along the intake. If the idle smooths out or speeds up, then it's an intake leak.