Yes, the P0300 is all I get. The fuel filter was changed a week ago (regular maintainence), which can rule that out. No air leaks, and I'm pretty sure the cat converter is in good enough shape. I haven't changed anything, Minerman, so I'm sure those aren't the problem. I guess I will have to see how the plugs and plug wires go. If that fails, It will be in the shop the next business day.

 

An engine is more prone to misfire under load than at idle for various reasons.

This is from OBD-codes.com

P0300 Code - Cylinder Misfire
Technical Description
Random/Multiple Cylinder Misfire Detected
What does that mean?
Basically this means that the the car's computer has detected that not all of the engine's cylinders are firing properly.
A P0300 OBD code indicates a random or multiple misfire. If the last digit is a number other than zero, it corresponds to the cylinder number that is misfiring. A P0302 code, for example, would tell you cylinder number two is misfiring. Unfortunately, a P0300 doesn't tell you specifically which cylinder(s) is/are mis-firing, nor why.
Symptoms
Symptoms may include:
[ul][*]the engine may be harder to start[*]the engine may stumble / stumble, and/or hesitate[*]other symptoms may also be present[/ul]
Causes
A code P0300 may mean that one or more of the following has happened:
[ul][*]Faulty spark plugs or wires[*]Faulty coil (pack)[*]Faulty oxygen sensor(s)[*]Faulty fuel injector(s)[*]Burned exhaust valve[*]Faulty catalytic converter(s)[*]Stuck/blocked EGR valve / passages[*]Faulty camshaft position sensor[*]Defective computer[/ul]

Possible Solutions
If there are no symptoms, the simplest thing to do is to reset the code and see if it comes back.
If there are symptoms such as the engine is stumbling or hesitating, check all wiring and connectors that lead to the cylinders (i.e. spark plugs). Depending on how long the ignition components have been in the car, it may be a good idea to replace them as part of your regular maintenance schedule. I would suggest spark plugs, spark plug wires, distributor cap, and rotor (if applicable). Otherwise, check the coils (a.k.a. coil packs). In some cases, the catalytic converter has gone bad. If you smell rotten eggs in the exhaust, your cat converter needs to be replaced. I've also heard in other cases the problems were faulty fuel injectors.
Random misfires that jump around from one cylinder to another (read: P030x codes) also will set a P0300 code. The underlying cause is often a lean fuel condition, which may be due to a vacuum leak in the intake manifold or unmetered air getting past the airflow sensor, or an EGR valve that is stuck open.

Also check for arching & crossfires between the plug wires themselves and the plug wires and ground. Make sure you have the proper spark plugs and spark plug gap, and that the plug wires are routed according to spec in order to minimize crossfires.

 

Thank you, all. I'll be changing the wires this coming Saturday (I sure hope). If this is the problem solver, I'd like to SeaFoam my engine. Now, has anyone done that? Recommend it, or no? It sounds promising, but I'm not one to take a risk like that unless I know it will do well.

 

The sea foam job should annoy the neighbors. Good to do on a summer weekend when the neighbors are grilling their hot dogs in the back yard. LOL

 

Yep. Replaced the junk wires with AC Delco wires. Runs smoother than ever. Thanks, all, who contributed.

 

Hi again, all. Two weeks have elapsed and this past Monday, while driving to work, Cylinder 3 completely shut down. I had the codes checked and I had a P0303, so I replaced the spark plug. It ran and idled fine for twenty minutes, and then I turned it off and went inside. The following morning, while on my way to work again, I felt a stumble, and then again, a complete misfire. Had the codes read again, and it's the same pesky P0300. I KNOW it's a new plug, wire, and coil pack. The ignition module tested fine about two and a half weeks ago, so now I'm at a complete halt.

Any suggestions, ideas, or thoughts? Please share!!

 

What did the bad plug look like when you replaced it? You may want to look at the ignition module itself again, as it can generate the random misfire. They tend to go bad a lot. Also check your fuel pressure and pressure regulator.

 

how do I changemthe crankshaftn position-system variation

 

have you made sure your plug wires aren't resting on your exhaust manifolds?
because that will burn a hole into them in a matter of minutes.