02 Roadking engine miss
You have to go through steps to isolate if it is a fuel/air, compression, or electrical problem. Changing parts out gets expensive. Start with a can of wd40, and spray it around the intake manifold where it meets the cylinders. If the engine smooths out, you may have an intake leak.
With the engine running, use something to pull the spark plug wires one at a time, to see which cylinder is missing. Make sure the tool you use to pull the plug wire is well insulated!

If you have compression gauge set, run a compression test. Might also need to do a leak down test. If you don't have the tools, might have a shop run those tests for you. You could have carbon buildup on a valve, or excessively worn valve. Does the engine pop either through the intake or the exhaust? That might indicate a valve is burned/cracked/bent and needs replacing.
Does the engine smoke? If it does smoke, when does the smoke occur? Like does it smoke when you first start it up, then a short while later the smoke isn't as bad? Or, does it smoke all the time? Is the smoke white, or black? Black smoke indicates too much fuel going to the engine. White smoke indicates oil being blown by worn piston rings, or leaking valve stem/seals, or even just a blown/leaking gasket.
Electrical problems usually necessitate the use of a multi-meter. If you don't have one, you will need one if you are going to perform your own maintenance/service.
You say you have the service manual, go through the Trouble Shooting section, to figure out how to narrow it down a bit...

Do you know the history of the engine maintenance? At 80K on the odo, it could be close to time for a top end rebuild.
Last edited by Def Mute; Jul 29, 2013 at 10:05 AM.
Last edited by rkingstp77; Jul 29, 2013 at 03:00 PM.



