Clean94hatch

Vehicle in question: 1995 Civic hatch DX 1.5l
Problem: won't start

So a friend of mine decided it would be a good idea to play a prank on me. He unplugged one of my spark plug wires *at the distributor*. I didn't know he did this, and I went to start the car. As I'm about to leave, he walks over and says "oh yeah, you should plug that spark plug wire back in, I thought it would make a more obvious difference in the engine." I go under the hood and see the wire hanging about 1/8inch from the contact point on the distributor. I can see the spark arcing from the distributor to the plug wire. ...then the car shuts off on its own. It won't start again. I've checked all the fuses, disconnected the battery to try to reset the ECU, taken off the distributor rotor to check it out, etc.

I have no idea what to try next. A friend of mine suggested that the ignition control module inside the distributor might have been fried by the spark re-arcing backwards into the distributor or something like that.

Any ideas?

ezone

Probably needs the ignition coil.

I would check point dwell with a dwell meter. If there is any reading at all --when cranking-- but no spark, the coil is bad.


And your "friend" needs a "friendly talking to".

Clean94hatch

Yeah...he's a serious d-bag sometimes. I got it covered.
what is dwell? I've never heard of that.

ezone

Dwell is something used back in days of yore, back when the Dead Sea was just sick. Back when the Earth was young.

Back in the days when everything had a carburetor, dwell was used to set/adjust points inside the olden distributors.

Clean94hatch

ha! "back when the Dead Sea was just sick". That's a good one.
No offence, but dwell doesn't seem to apply to my car? It doesn't have a carburetor, and points haven't been used on a car in 25 years.

ezone

Doesn't matter.
You asked what dwell is.
I answered.
I didn't say your car had a carb or points.

The ignition coil used on your car is the same basic ignition coil that has been in use for about the last 100 years or so and uses the same principles and construction.
Yeah, it is smaller and a different shape. That's irrelevant.

Dwell (also known as point dwell) is a simple way to measure (and prove) activity from the transistorized switching unit (igniter).
The igniter took the place of the old ignition points.
It does the same job that the ignition points did, that is turn the coil on and off.
Points were just a mechanical on-off switch, mechanically actuated electrical contacts.

The same measurement method is still effectively used.
Coil is the same, and measuring it is still the same.
Make sense?

All I want to know is if that coil is getting turned on and off by the igniter. Then I use that info to make my decision about the next step.




Back in the olden days, one could use a light bulb to check for a "points signal" (contacts opening and closing)......
Nowadays, the coil "on" time may be so short that an ordinary test light may not illuminate visibly. Same goes for an LED test light, too easy to miss.
A dwell meter will show the switching activity (point dwell) if it is present during the cranking test.

These meters are not mythical. They still exist and can be bought with money. Older folks may still have them in their toolboxes. Maybe the Zone can rent one out, IDK.
I am not THAT old yet.

HTH

Clean94hatch

By "lightbulb", you mean something similar to a timing light? When that wire/plug fires, it will cause a light to come on?

That makes sense. That's simple electronics.
I'll ask around for a dwell meter, but I think I've already conducted a fairly conclusive test. I took the spark plug out, hooked it up to the boot, and turned the engine over. None of the spark plug wires/boots caused a plug to fire.

ezone

No.
Not a timing light.
Timing light triggers off of 10kV or more.
Far simpler than that.

A simple incandescent light bulb.
A test light.
A plain bulb on 2 wires.
Or a wire and a probe.
Like this





But these can't normally be used to check if the igniter is firing the coil.
A dwellmeter can show it.

Clean94hatch

Ok. I'll try to find a dwell meter and give you a reading tomorrow.

Either way, what's the next step?

If there is no current whatsoever passing through to the spark plugs, what does that mean?
I guess I should just keep tracing down the line until current shows up.

If there is current passing through, what's next to check? Is there a fuse for the fuel pump somewhere? I couldn't find one.

ezone

Ok, you would hook it up the same as if you were checking points. One lead on battery negative, the other lead on the coil negative terminal.
Meter set on 4 cylinders. (probably says 90* at this point)
Crank the engine while watching the meter.

Is there ANY reading other than 90* ?
Even like showing 2 degrees is good.




If the answer to the above is 2 degrees and there is no spark, it needs a coil.





The coil isn't making sparks.

That's what I'm trying to get you to do.


Hold up. Duh.

I just reread the first post.
I replied totally expecting the prankster to have caused the coil to go dead without actually getting you to confirm it.
Sorry.
Did I ever ask you to check to see if it still has spark or not?
Does it have spark?
I've been assuming the engine has no spark at this point. You need to assess this before going any farther.

If you say it has spark, then we need to know how big of a gap you can make the spark jump across.
A good system will throw a lightning bolt across at least a 1/2 inch gap at the end of a plug wire, or more.
(If you were to make the same check directly out of the coil inside the distributor, it would be closer to 3/4 inch+ of gap.)