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: 114,918 (75,000–170,000)
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
28 people reported this problem
Viewing 1 - 5 of 5 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.
Misfire under load. Bucking and jerking under load. P0304 and P0090 codes
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!
misfire code report, car stop,