Topic: Distributor cap issue

[dwtaylorpdx]

In general, its not 100%, but if you widen the gap it increases the current in the sparc and causes
more burning of the contacts in the distributor. I usually try and find a cap with Brass not
aluminum contacts when running a hotter ignition setup. I also find if your running stock wires
and bump the gap they seem to break down and wear out faster, not scientific just seems like they do...

It likely did not ruin the coil, the coil is just getting old and the windings insulation breaks down with age.
Some last forever some last a few years./// Kinda luck of the draw there.

I'f the coil is over say 7 years old, it might be worth replacing with a quality
replacement and keep the one you have as a spare.

One thing to note, if you didn't know, the distributor in that motor distributes sparc and provides
the cam position sensor feed, which triggers the fuel injection, the spark is controlled by the crank position sensor.
On mine there is no adjustment for timing on the distributor unless you pull the distributor and clock it a tooth.


Dave

[Lu]

So I threw in a new accel ignition coil.  Within a day, the contacts were burned again.  So I guess it's not the coil.  Back to the distributor leaking oil, there would be residue inside the cap, right?  I don't have any residue.

What else can I try?  I appreciate all the advice

[dwtaylorpdx]

I'd check plug wires(resistance)  and put in standard plugs with the stock gap. See if that helps?

Yes you'd find some residue in the cap if it had the oil leak issue.

Other than that I'm stumped, HMM. If you have a meter with peak reading memory,
you could check the voltage at the coil on the low voltage side, maybe your getting
too many volts in the system? (Totall wild guess here!) At least check the alternator
charge voltage across the battery terminal.

Dave

[sharpxmen]

I'd check plug wires(resistance)  and put in standard plugs with the stock gap. See if that helps?

Yes you'd find some residue in the cap if it had the oil leak issue.

Other than that I'm stumped, HMM. If you have a meter with peak reading memory,
you could check the voltage at the coil on the low voltage side, maybe your getting
too many volts in the system? (Totall wild guess here!) At least check the alternator
charge voltage across the battery terminal.

Dave

x2 on all that
I was thinking the same thing as far as the charging voltage but it's a long shot so i didn't mention it - now that you did maybe is not that wild of an idea.

other than that it sound pretty misterious

[dwtaylorpdx]

Aha, wait a second, have you checked the polarity of the coil connections? If the coil is backwards it will do odd things...

Dave

[Lu]

Well, it seems that there is only one way the connection can go on.  I'll run a check on the charging system soon and the meantime I'll just deal with it.  Thanks for all the help.  By the way, what should the normal voltage coming from the alternator be?  What should the gauge in my dash read?

[dwtaylorpdx]

The dash gauge is usually not very accurate, you should be somewhere between 13.9 and 15.5 as I recall, but I'd check a manual....

Dave

[sharpxmen]

Aha, wait a second, have you checked the polarity of the coil connections? If the coil is backwards it will do odd things...

Dave

i don't know if it would matter that much at the distributor cap and rotor, more at the spark plugs i would think (polarity at the electrode)  - interesting point though

[Lu]

Here's an update.  I picked up a set of Autolites and made sure they were gapped properly at .035 and ran them for about a week including a 4 hour round trip on one day.  The same burning effect on the cap and rotor contacts happened with the Autolites as well as E3's and +4's.  I re-gapped the Autolites to .055 because I have a hotter coil now and I got a little more boost out of them but still with the burning effect.

The Platinum +4's are by far the best plugs I've run.  They give a noticeable increase in pep and on hills I can maintain 60mph no problem, given that it isn't too steep of a hill.  I also get 1-2mpg better with the +4's. 

Since the +4's make me happier, I'm sticking with those for now.

So what now?  I've had a Firepower ignition kit on my fantasy list for a while...would it help to install one?


Thoughts?

[sharpxmen]

try the stock coil with and gap back at .035

[dwtaylorpdx]

if you have ignition problems on most modern cars,
going more powerful will usually just aggravate the root cause.

One thing I have done in the past is taken an old cap and cut a hole in
the top so I could see the #1 contact, then run the motor to see where
the rotor is in relation to the contact when it fires.(A timing light will help see the rotor....)

If your off a tooth, its possible to have the arc jumping way too far....
Which would raise the current way up in the arc the distributor.
Usually the engine does not run very well but its possible the computer is
dragging the timing just far enough fix it... Would a thought the cam position
sensor in the distributor would have forced a code but the mopar computer
ain't the sharpest knife in the drawer....

Dave

[Torch_Ind]

if you have ignition problems on most modern cars,
going more powerful will usually just aggravate the root cause.

One thing I have done in the past is taken an old cap and cut a hole in
the top so I could see the #1 contact, then run the motor to see where
the rotor is in relation to the contact when it fires.(A timing light will help see the rotor....)

If your off a tooth, its possible to have the arc jumping way too far....
Which would raise the current way up in the arc the distributor.
Usually the engine does not run very well but its possible the computer is
dragging the timing just far enough fix it... Would a thought the cam position
sensor in the distributor would have forced a code but the mopar computer
ain't the sharpest knife in the drawer....

Dave

wouldn't hurt to align up your timing marks and pull the distributor and check the teeth I have seen vehicles wear the teeth off and cause problems

[Jeffy]

The PCM should be able to compensate for a tooth or two though.

[sharpxmen]

The PCM should be able to compensate for a tooth or two though.

the spark would occur at the same advance point relative to tdc regardless of the dist or rotor position based on the flywheel to crank sensor signal

[dwtaylorpdx]

There is a max number of degrees the PCM can pull, I think its < 40...
For instance if you have all the wires 1 connector off on the distributor
the PCM can't deal with it...

I'm just kind of brainstorming, only excess current could burn the cap,
SO something is causing that... Hmmm

Dave