I know i've seen this discussed on here before, but couldn't find the thread i was looking for w/ the search. Anyway, i've got a serious misfiring problem on my pickup. The wires are pretty new, less than 5k miles, and the plugs are fairly new, less than 25000 miles. I really don't want to pull all the plugs to find out that there's nothing wrong w/ them, I'd rather check the wires first. Someone was saying you check the resistance or something such as that?? Any help would be appreciated.

 

You can check them with an ohm-meter to determine there resistance. I don't remember the exact number but it would probably be good if they were all under 2,000 ohms. You can just measure all of them and if one has way higher resistance than the others then you know you have a problem.

Also, when it is dark out and the truck is running you can squirt the wires with a spray bottle, if they arc you know the wire's insulation is bad and they are crossfiring.

Keep in mind, the plugs could be the problem. Sometimes they arc internally and you'll see that the white ceramic insulation has turned brown. (a little brown is normal on all plugs). I've seen this with a lot of champion plugs. Pulling the plugs and looking at the ends will at least tell you which cylinder is misfiring.

You mention that the plugs and wires are new, how about the cap and rotor? Or do you have electronic ignition?

-Jon

 

As my signature says, I've got a 97, which just has the two coil packs. I've had problems in the past w/ plug wires. I had one replaced last summer and then this february I purchased a new set. The plugs are Bosch platinums, but.. I'm thinking they about have to be the culprit. If I only have 5,000 miles on those wires and they are ***** already, I'm gonna be one pi$$ed dude when i take them back. It takes way too long to change plugs and wires on these damn cluttered engines to be doing it all the time.

 

If the engine light is flashing try going to an Autozone or one of the places where you can use their computer reader. I think Autozone is free or 20 bucks or something but make sure they pinpoint the exact plug/wire, etc. Could be one of the coil packs too. Sometimes a plug wire can pop off the plug as well.

It pays to use good quality plugs and wires on these trucks. It seems like they "eat" the cheap ones.

Sometimes at night even without using a water mister you can see arcing if there is any. Make sure to pull the bulb in your hood to make it dark.