96 Honda won't start Part II

Well folks I have a 96 Honda Civic that ran fine and then one evening just
won't start. I was advised by folks here to get a scanner before going
further and I have done so. Tried it today and there are not any stored
codes! I have done the following so far;

Replaced the distributor cap and rotor
Had the ignitor checked, they (auto parts store) report it as good
Removed the air cleaner and sprayed carb cleaner in intake to see if it
could be a fuel problem - no change
Check the coil with an ohm meter and it checked good, I compared it to a new
coil to make sure
I hooked a wire from the coil spring to an air gap type spark plug tester
and get spark there but not at the plugs
Replaced the new distributor cap and rotor with other new ones thinking they
might have been bad - same thing

motor turns over fine it just won't hit! Any ideas, could the timing belt
have slipped?

Thanks from a shade tree mechanic,
Dan

 

Why would you take the long way around? Do this instead:
http://www.tegger.com/hondafaq/startproblems.html#checkspark

Shotgun approach does not work. Be methodical.

Check timing with a timing light. Easy as pie.

 

I did check the plugs as the link suggest and there is no spark.

To check timing with a timing light requires spark...doesn't it?

 

After reading the page referenced I wonder if the coil could be bad. The old
plugs were badly worn and I wonder if the high voltage side could have
shorted to ground. The coil could still be good under a normal resistance
check but under load the spark could jump to the case. Any thoughts?

 

About 3 or so years ago my car started running very rough and uneven. I checked
the resistance on the aftermarket spark plug wires and they were within spec. I
can't remember the sequence of events in replacing items but it turned out that
some of the wires were shorting out inside the spark plug tube. The cause was
probably a combination of cheap wires and worn plugs. Again I can't remember
but I think it continued after I put the new plugs in, which helped me diagnose
the problem.

I don't think this is your problem though, I'm just brainstorming here. Who
knows what ideas it might "spark".

Checked with new plugs?

 

It does indeed.

Check the rotor for continuity, to make sure it's OK.

Then go here:
http://www.tegger.com/hondafaq/startproblems.html#badcoil
See near the bottom of that section for how to check the coil.

If you have a tach, it's even easier.

 

Tegger,

I have done that and in fact have the second new rotor installed as we
speak. Still a no-go. This is truly frustrating as I think I have covered
all the bases. I am contemplating a new coil as a last resort as I don't
have any other ideas.

Dan

 

Well folks it's fixed. After reading the FAQ (thanks Tegger) and considering
that the plugs were badly worn I decided last night that the coil had to be
the culprit. So today I took it out and sure enough there was a pin hole
burned in one corner. The coil checked fine as far as the primary and
secondary coil resistance is concerned, and if a wire was hooked to the coil
out post and then to a plug tester it would fire. My theory is that since
there is not any resistance, so to speak, in an ordinary wire it would fire
fine but try to push the spark through a high resistance plug wire the fire
would take an easier path out of the coil pin hole to the distributor body.

Thanks for everyone's help and especially Tegger and his FAQ.

Dan

 

Excellent! Glad it's fixed.

Is there any way you can take a photo of the coil, specifically the area of
damage?

As far as current leakage goes, I have found it's not often possible to
diagnose a bad coil by checking resistances with a multimeter. Pushing 3V
through the coil with a tester will give very different results than when
pushing 20,000V through it in actual operation.

Electricity will take the path of least resistance, so I think your theory
is sound: a compromised coil body would have less resistance than a 25,000
ohm plug wire, but more than a 0 ohm copper wire.

Kudos to you for intelligent diagnostics.

 

Tegger, yep I can get a picture, I'll get it tomorrow and send it to you?

Dan

 

Please do.