Testing plug wires

[Otto]

Need help quick -Testing plug wires

I have a job interview soon and my truck just started misfiring yesterday, especially when the engine is hot will miss at idle too. So wanted to check the wires but have no clue if I used the right settings on the ohm meter. I set the switch to 20K in the ohm range and plugged the two meter terminals up to "VΩ" and "com"(max 1000v). I tested the each sides of the 6 wires and got some mixed results:

wire 1 - 4.68
wire 2 - 4.52
wire 3 - 3.88
wire 4 - 9.52
wire 5 - 6.02
wire 6 - 6.71

Wire 3 was all over the place and skipped back and forth from 2V up to 16V and rested lower when the wire was still. Wire 4 was consistent but higher compared to 5 and 6(longer wires). So what do you think? Anyone have any ideas cause I need to travel about 35kms everyday to my job and it misefires bad at cruise speed and idle after it warms up.

 

[cocoasranger]

My manual which covers models 83 thru 92 gives the following info which should be the same for later models. Measure each wire. A reading of UNDER 7000 ohms PER FOOT is acceptable. A reading of over 7000 ohms PER FOOT is defective.

If you had your range setting on 20K, your figures sound way high. Plug wires usually don't fail suddenly, but slowly degrade over a long time. I'd have a mechanic give it a quick check if you need the problem solved asap. Good luck on your interview.

 

[BLUE "B"]

I f they are over 2 years old just replace them along with your plugs. You'll spend moe time and money chasing the problem than you would if you just replace them. Good luck on your interview.

 

[snake]

Get some sparkplug wire pliers and remove one wire at a time when it is running- that will let you know which one is misfiring- it will be the one you pull off that doesn't make it run crappier. Check that plug and maybe the compression on that cylinder if you have a tester.

If it hasn't had wires in a while replace them with factory wires. The good factory ones (and factory plugs) usually last over 100K.

 

[Otto]

Well I repalced the plugs yestereday with champion single platinum. It took away most of the misfire and hesitation at cruise but now it seems to running a little rough when hot with acceleration ie. lack power, gears are jumping, revs high and clunks into 2nd gear, heavy on gas, basically all the symptoms of a vacuum leak. Its still getting the spark I think it feels more like the timings off or it's misfiring early into the intake(air tube smells gassy). Not sure, Im waitng for my obd II in the mail so I can check the computer.

 

[Otto]

^But I'm pretty sure it's running lean. It had the same symptoms when the EGR sensor went out in the winter. My best guess is a temperature sensor cause it's usually the worst when it's hot after driving 10+ kms.

 

[dennis461]

Look under the hood at night in the dark, engine running.
Make sure the hood lightbulb is off if you have one.
Look for wires sparking to the engine parts.
If you see sparks, the wires are shot, no matter if old or new..