something killing my coil

[Chris Martin]

So the other day I was out for a drive and stooped at a buddies for a visit. Went to leave but the car wouldn't start, no spark. Replaced the coil and it started. Just put an electric fuel pump on it today, went to start but no park AGAIN!? It has the Mopar Orange Box that it several years old (around 12) and while searching here it sounds it may be the problem. Any thoughts/suggestions/recommendations?

 

[Mrmopartech]

How do you have it wired up in the system,are you using the ballast in the wiring,and what coils are you using,a point type or a electronic type coil,mrmopartech

 

[Chris Martin]

I am using a 2 terminal resistor and using an Accel cylindrical coil. The one that quit the other day had been used since the electronic conversion with no issue, hence no hesitation replacing it

 

[67Dart273]

What exact part number? Some of those require an ADDITIONAL resistor along with the factory resistor

 

[Chris Martin]

mopar box #P4120505, Accel coil #8140c, an Echlin (NAPA) resistor ICR11

 

[67Dart273]

Well, 'ell!! Jegs shows that coil has a resistance of about 1.4 ohms, the same as a Mopar Essex coil, so that's OK

I found a listing, shows the NAPA resistor is actually higher than factory, so it should not be drawing too much current

You don't leave the key on? when stopped?

Make sure the ECU is well grounded. I spose it's possible you actually have two bad coils, pretty rare.

 

[1970 La]

We had the same thing happen on my sons truck. Took that same accel coil off and put on a 1974 coil and hasnt failed to start yet. It would get damn hot with 8 volts to it.

 

[Chris Martin]

No I don't leave the key, it's either running or the keys are out. I just ordered another coil and a new module through napa prolink so i will get them on tomorrow after work and keep you posted. I have a feeling it's the module, I can't see two coils (one brand new) failing with 15 mins. drive time.
Thanks for the input thus far

 

[EL5DEMON340]

Make sure your reluctor to pickup has the correct .008 gap. It will act like like no spark when you try to start.

 

[67Dart273]

Might be worth mentioning..................I found reference to TWO Accel 8140 coils

8140C seems to be more like a stock coil in resistance

But the 8140HV..........here:

http://www.oreillyauto.com/site/c/d...del=Continental&vi=1342314&pt=C2377&ppt=C0334

is the one I remembered, notice:

For points applications a 0.85 Ohms ballast resistor (part #150001 not included) must be used in conjunction with the vehicles original ballast resistor, if so equipped.

This means the factory ballast must be used IN SERIES with an additional .85 ohm resistor

You might check your coil, carefully with an ohmeter when you get it

 

[Chris Martin]

Might be worth mentioning..................I found reference to TWO Accel 8140 coils

8140C seems to be more like a stock coil in resistance

But the 8140HV..........here:

http://www.oreillyauto.com/site/c/d...del=Continental&vi=1342314&pt=C2377&ppt=C0334

is the one I remembered, notice:

For points applications a 0.85 Ohms ballast resistor (part #150001 not included) must be used in conjunction with the vehicles original ballast resistor, if so equipped.

This means the factory ballast must be used IN SERIES with an additional .85 ohm resistor

You might check your coil, carefully with an ohmeter when get it

I have switched to electronic many moon ago but I will re-check.

I took the dist. cap off and all looks good.

 

[nm9stheham]

Just another possibility: The older Accel coil could have just finally failed and the new could be the one needing the extra ballast described above, and thus failed quickly without the added resistance....

I'd check the new coil as noted by 67Dart273 but do it the right way with such low resistance parts. Be sure the put the ohmmeter leads together first and note the resistance reading of just the 2 leads, then measure the coil and subtract out the lead resistance to get the actual coil resistance.

0.5 to 1 ohm of lead resistance alone is not uncommon, and for low resistance value parts like this, the added step to measure the lead resistance and subtract it out of the total reading is important. A reading of 1.4 ohms on your meter might look good, but the part being measured might have only 0.5 to 1 ohm or actual resistance when the measurement is corrected for lead resistance.

BTW, the electronic ignition module behaves very much like a set of points, alternately closing and opening the coil - to ground. It could short out partly I suppose and excessively heat the coil.

 

[Chris Martin]

Well, so far so good. Replaced the Orange Box with on from Napa and it's still running. Thanks to all for the suggestions. Cheers.