1990 Toyota Van

Engine Performance problem
1990 Toyota Van 4 cyl Two Wheel Drive Manual

Hi. My car is a toyota hilux van 2y engine. The problem is misfiring. When I change the plugs it runs smoothly for say 60km then the problem restarts again. What could be causing this
January 9, 2010.

An engine misfiring can be caused by worn or fouled spark plugs, a weak spark (weak coil, bad spark plug wire), loss of compression, vacuum leaks, anything that causes an unusually lean fuel mixture (lean misfire), an EGR valve that is stuck open, dirty fuel injectors, low fuel pressure, or even bad fuel.

Jan 9, 2010.