A little electrical Help please

[stomper]

My rover died about 500 yards from my house on the way home from work. It simply shut down electricaly, and would not start again. It is getting fuel, I replaced the coil not long ago, and I replaced the points with a new set from the tool box. I get a good spark from the center wire on the distributor when I crank it over with it about a half inch from a metal ground, but I can't get a spark from the plugs.

The condensor is one that came with the truck, I thought this may be the issue, but I don't have a spare. Is there any way to test this? Also, the low tension lead looks O.K., but may be at fault. I can't test it though, because the prior owner put in an MSD ignition system. The low tension lead hooks to this. (it is on my list to remove this, but I need to get it running first)

Any Ideas of something else I may be missing? I hate electrical stuff.

James

[bkreutz]

If you're getting spark from the coil wire, that tells me the points and condenser are working properly, I'd be looking at the rotor or the center pin in the distributor cap. Somehow the spark isn't getting from the coil to the individual cylinders.

[SafeAirOne]

Let me ask..

When you say "I get a good spark from the center wire on the distributor when I crank it over" do you mean that you removed the middle wire from the distributor and you are getting good spark from the coil?

If so, your primary wire is doing its job, as is the coil and points and the distributor shaft is spinning. So, if you are certain that it is an ignition issue, and that the plugs aren't getting spark (with the center lead reattached, of course) that only really leaves:

Broken/defective rotor

Broken/defective distributor cap

Defective wires (especially evident if it is humid/damp/wet outside)


If the timing was off, you should still get a spark at the plugs, albeit at the wrong time...

[EDIT] Drat---bkreutz summarizes better than me and types faster too!

[thixon]

Have you checked to make sure the points gap is correct (or if there is actaully a gap at all)? You say you swapped things out recently, maybe you did'nt tighten things up enough? Just a guess.

Check all your wiring connections around the ignition (especially the wire from the MSD to the dist, either red or white, I cant remember). It sounds like the MSD box is working, otherwise you wouldnt get a spark at the dist.

An easy way to test the condensor is to remove the cap and rotor. with the ignition on, take the high tension wire, and hold it close to any nearby place on the engine to ground it. Take a screwdriver and pry the points open, and then close them. If they're good, you'll get an arc across the points thats blue in color, straight, and makes a snap sound. If they're bad, the arc will still jump the gap, but it will be weak, white in color, and barely make much of a noise. You can test with a multi-meter, but based on your comments about hating electricals, and having little experience, lets start here.

[stomper]

Thanks for the help everyone. Mark, you are correct. When I take the center wire off the distributor, and I crank the engine over, I get a spark. So the coil seems fine. (it was replaced last fall anyway). The points were gapped correctly, but because there was some mild corrosion, I swapped in a new pair. This was after it stopped working. The points were put in correctly, I'm sure of that. I did file the rotor button to clean it up, nothing appears wrong with it. The contacts in the distributor cap all look perfect. The cap (and Rotor) were replaced last fall when I tuned it.

I only pulled the 1st spark plug to check for spark. Didn't see anything. If the wires were bad, what is the chances of all of them going at the same time? Wouldn't that cause a misfire, not a breakdown?

I have a multi meter, It is a really nice fluke model. I inherited it from my father, who has passed on, so I can test for continuity, But I am clueless to electrical in general.

[kevkon]

No chance that your plug wires are the problem, unless they are all cut.
You have a good spark at the primary, so the coil, MSD box, and points are at least functioning. I would recheck the spark at the plug, if there is no spark there then it's a distribution problem. Some causes of that, broken dist. drive, broken contact in the distributor, or bad connections on the ignition system.

[bkreutz]

Check your cap with your meter, you should have continuity from the outside (where the coil wire goes in) to the inside (where it contacts the rotor) Also, make sure the internal button isn't stuck in the up position (not in contact with the rotor) You can also use the meter to check from the center of the rotor to the tip.

[mongoswede]

here is a good layout overview for your DVOM. The continuity setting usually has a little sound symbol next to it because it will beep when you have a continuous circle.

[stomper]

Well, it was a defective rotor button. I don't think I have ever seen one fail before, but when I put a bran new one in, she fired right up. Now to replenish my spares! Thank you everyone for the assistance. Now I feel much more intimate with my electrical system, and my multi-meter.

[mongoswede]

might be one of those things to keep a spare of in the truck...spare cap and rotor.

[stomper]

Funny you should mention that. I had a brand new set of points, a cap and a rotor button with me at the time of the breakdown. I now need to order up a new set for restocking my spares. I was indeed equipped to handle the entire project on the road, but with my limited experience with electrical systems, I guess I feared for the worst, and I admit, this failure did have me perplexed for a little bit. I would have been there all night figuring it out had I not been so close to home.

[mongoswede]

Everyone always assumes the worst when their car dies and usually its very simple. More than one engine computer has been replaced because the fuel pump fuse was burned out.

[SafeAirOne]

More than one engine computer has been replaced because the fuel pump fuse was burned out.

...not in my 109.