Misfires Under Load on Mazda Protege

Problem Description and Possible Solution

Misfires under load (acceleration) can be caused by leaky spark plug boots. When a spark plug boot leaks, it allows the spark to arc, or jump, to the cylinder head. New spark plug wires will be needed.

Problem Data
RepairPal Verified
Average mileage: 128,260 (75,000–235,000)
Engines affected: 1.6L 4 Cylinder, 1.8L 4 Cylinder, 2.0L 4 Cylinder
14 model years affected: 1990, 1991, 1992, 1993, more1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003
32 people reported this problem
Viewing 1 - 6 of 6 comments
Engine chugs, jerks or bucks. The idle is rough and car often refuses to start. It takes several attempts for ignition to take place. Got a P0304 code and replaced Cylinder 4 coil. Also adjusted the idle. Have yet to notice any results.
Misfires only during heavy acceleration. This began after replacing one coil and 4 spark plugs. no solution as of yet.
Misfire under heave acceleration and no CEL, I replaced plugs, wires, and coil boots and cleaned the MAF with no results, then I pulled a plug to check the gap and it was .30 larger than it was supposed to be, set the correct gap of .30 and the misfire is gone!
Put 4 new sensors, filter,mas hose , spark plugs and wires car sounds like it not getting enough acceleration and it uses a lot of gas