Spark Plug Wires-Testing

[RageRover]

How can anyone test the spark plug wires to be absolutely sure that they are bad or about to go bad? I had change plugs about 2 months ago, and today she my RRC started misfiring occasionally during some acceleration periods. Now for the last week or so, she has never been dry, like it rained constantly and still is raining. Dunno if the water ad moisture will mess with the plug wires or not. I checked the plugs and wires for visual stuff, i.e. pulled the plugs (which were fine and gap still correct on all 8), checked for fraying in the plug wires. Nothing "visually" was wrong. Now I know it isn't fuel injectors, I had those run through a "de-carbonization" process at the school awhile ago, by one of the high performance instructors. They also all test in spec.

Plus the misfire definately feels ignition related, for one I can smell a little gas from the exhaust after pulling in after a drive.

So I can just about figure that the plug wires might be going south on me, I am not sure, just is there a way to electronically test these wires? I know the old trick by pulling the wire and having it arc to ground via engine block, frame, etc., is one way, but just shows that the wire can hold continuity.

This seems like a good question to ask. LOL

[Paul Grant]

If you want to check for arcing, the best why I found was to mix a little salt in a spray bottle with water. After it's dark, go out and start the truck up, open the hood and lightly spray the salt water mix on the ignition wires. You'll see a light show if you've got a real problem with arcing everywhere, otherwise, a few flashes of light are okay.

If you have a problem with your wires, spend a few extra dollars and go with a set of Magnecors. I, and a great many other Rover owners, have found them to work especially well with these trucks.

By the way, did you sort out your bonnet issues? I still have that Beluga black bonnet from the '95 I took in.
Cheers,
Paul

[p76rangie]

You check the OHMs resistance on them. The longer the lead the more rsistance. The shortest lead should be about 5 OHMs and work up from there. If they are wire leads, they should have virtually not resistance. While testing them wringle them around a bit to make sure that there is not a break in them.

Ian

[OkieRover]

^^^ x2
I was going to say just about the same thing.
As a rule when I replace the plugs I replace the wires too. And I'll tell you why. I have rotten luck with the wires when I'm pulling them off the plugs. It seems like no matter how careful I am I manage to tear up one plug wire. Happens every time.
So I just save myself the trouble and jerk them damn wires off, showing them who's boss, yeah! Sorry about that.

[Disco Mike]

Pat,
Two thinhgs to look for with plug wires resistance and insulation. Rover and others don't make a wire to handle their full voltage capabilitys, they look at cost.
Even new Rover wires only carry about 37,000 volts while the coil pack get up over 50,000 volts.
If you have over 40,000 miles on your old wires, get rid of them, put on a set of Magnacor 8mm wires, which can handle voltages in the mid 50,000 range.
My set are over 45,000 old and still going strong.
You really want to have fun, next time you change your plugs go to the Bosh Platium Plus 4's along with the Magnacor's, you will get lots of extra torque.
Mike

[RageRover]

I will probably have to replace the wires then. The wires tested to high of resistance on all wires yesterday. I will also try the salt and water in a spray bottle tonight and see what happens. This might account for why every time I go wheelin' and go through water, she misfires a lot.

BTW Paul, I have not found anything local anywhere, it is real sad. So when I find time, I might as well drive all the way to CT and pick up that hood when I can. Thanks!

[Disco Mike]

Pat,
If you need it, here is a good site for the wires.
http://www.roverconnection.com/
Mike

[RageRover]

Originally Posted by Disco Mike

Pat,
If you need it, here is a good site for the wires.
http://www.roverconnection.com/
Mike

Thanks Mike! Looks like some pretty good deals on the 8mm wire set from Magnecor!!

If my wires are arcing when I do the spray bottle test, I will order the 8mm set from Rover Connection. Thanks for pointing this site out to me!! Real cool stuff!! I notice the Power Chip they offer as well, but....er, um......LOL the price is a little steep, close to a grand!

BTW I have not installed that cheap little thing I ordered off of Ebay, I am gonna just see what damage it does to one of the donated cars at my former high school shop, my previous instructor their wants to see this thing do its "magic". LOL

[Disco Mike]

Don't base your order on the wires ability to not ground out on the engine, remember what your resistance test showed, just go for it.
Mike

[RageRover]

Yeah I guess your right, my DMM doesn't lie, at least I am sure as hell hope it doesn't. LOL

I looked at other wire sets, just stock OEM, and I think I could afford the extra $20 more for these wires. And do you think the use of a like a universal ignition Coil from Accel or MSD would be okay? I also seem to notice that my coil is old, stock, and is out of spec.

[Disco Mike]

I have heard a number of people go hotter on the coils with great results, you will develop more low end torque.
Mike

[RageRover]

That should be cool then!! The local Autozone retails MSD parts.

[azpaquin]

it can be moisture getting into the distro cap. how new is that?

[RageRover]

The cap and rotor are fairly new, when I first got the truck back in December, since then I only put on 6K miles. I will pop the cap off to see if any dirt or water got in there. Maybe a cleaning is in order. Not sure, but I will check. That is a good point BTW.

[RageRover]

Well I was just out at my truck and did the mix of salt in a water bottle trick, and did I see the Fourth of July!!! Arcs everywhere on every wire. It was nuts!! I took one of the wires off, and looks a little closer and I could see cracks in the silicone insulation. Yup time for some new plug wires.