RepairPal is your advocate for car care advice and guidance

Q: Misfire at idle runs rough on 1994 Mazda B4000

94 mazda b-4000 misfires at idle have changed egr - o2 sensor - plugs wires coil pack all have given more power yet still misfires. it appears to run more rough at times

Some times at highway speeds the speedomator will jump about 5 mile per hour.
Get a Repair Estimate
Guaranteed by certified locations nationwide. Learn more
RepairPal estimates are guaranteed at over 1,700 quality certified locations nationwide. Learn more
Check for any vacuum leaks. These can cause misfires at idle that will smooth out when you are on the road. When I say vacuum leaks, I also include a leaking intake manifold. And, if you ever get a check engine/service engine soon light on, be SURE to get the code(s)!
Didn't find what you were looking for?