I have a newly rebuilt 5.9 dodge magnum, I bored 30 over, complete rebuild. was running fin first 2000 miles then started getting a misfire code in the #3 cylinder, has new wires, plugs, cap button.

SOURCE: misfire at low speed light acceleration 22r engine proffessionly rebuilt

Sounds like the distributor advance is sticking for some reason. Is it mechanical?

SOURCE: I am getting a misfire

I've got a 2002 Grand Prix GTP 3.8L Supercharged V6, nearly the same motor.
I had the exact same problem, misfire on Cyl. 5 and random/multiple misfire.

I replaced all the wires, plugs, coils, and even the ignition module. My next thought was either fuel or exaust.

Replaced my Cat. with a 2.5" ZZP downpipe, and the car ran alot better, but still had a tiny bit of hesitation over 4000rpms.

So i checked all the fuel injectors, and the #5 injector was bad.

To check, get an ohm meter, remove the injector connectors, and contact the 2 posts inside the injector. They should read between 12.4-14 or so.

Mine was at 11.2.

Replaced all the fuel injectors, and she runs like a champ

SOURCE: misfire on #6 and #8 cylinder 1996 Dodge Ram 1500

Check the spark plug wiring . There are several places where the wires cross each other. These wire cross points MUST be at right angles to each other. Or you will have a misfiring problem.

Marvin

• 85242 Answers
• Posted on Nov 23, 2009

SOURCE: Misfire cylinder 5 2000 dodge dakota

when u press the gas pedal to go this opens the throttle valve, the idle speed of your engine is computer controlled, this is done by the ISC (idle speed control) airbypass valve, these parts get full of gunk and then get a stalling problem at or near idle, clean them by doing the following, if u don't understand the instructions seek help from your friend.
, Get a can of intake cleaner from any local parts store, not carb spray, intake cleaner, it is made by a company called CRC, remove the air intake hose to the engine, hold the idle high so the engine won't stall, then spray the can of cleaner into the intake while keeping the engine running, use at least 1/2 the can, shut down the engine and disconnect the battery for 5 minutes, then restart and complete a number of mixed driving cycles, town, freeway, stop and go etc., after a few days the problem will go away as the system will relearn to the clean intake.

SOURCE: 96 jeep cherokee misfires on cylinders 5 and 6

do a compression test on cylinder 5 & 6 you could have intake leak.and a leaking head gasket or worn valves in those cylinders.