Do you mean 6.5 Kohm for the secondary resistance?

Primary resistance for the DAC6093-type single coil is .6 ohm.

As I recall the primary resistance on the coils used in the original dual coil set-up should be .9 to 1.1 ohm

Cheers
DD

 

yes, I meant 6.5 Kohm secondary. My DAC6093 single coil measures .6 ohm primary, but will not let me rev AT ALL. My original dual coils both measure .6 ohm primary as well (disconnected from any wires) this is why I thought they were bad, but it seems to run better on this setup?

 

The original "old style" coil twins were 1.2 approx primary EACH. As Doug said.

Then when connected as they were/are, the primary is 0.6ish.

The module inside the amp is OK for about 1.0, but it is a strain.

 

yes, my original old coils (which I am running now) are individually measuring .6 ohm each on the primary winding. Which is why I originally thought they were bad. I have not measured them together. My new coil also measures .6 ohm on primary but will not allow rev over 3000 AT ALL!

 

So, 0.6 each would give 0.3 when siamesed, too low.

The "single" coil I use is 0.75, and is listed as a "Universal Electronic Ignition Coil", and has worked just fine for many, many years.

The tacho bounces off the end with ease.

I also use Echlin brand Modules, made in the USA, but I have not needed one for 10+ years. TP45B is the part # from memory.

The failure reports of the pick ups inside the distributor are starting to get more frequent, so maybe age is now creeping in????, not sure.

 

that is what I thought as well. So I’m wondering why this combination will let me rev that high with only a little stutter? And with the “single” coil measuring .6 I can’t rev over 3000 at all? Bad cell in battery? Bad Pickup?
Also to note, I did try running just one of the old coils (since it did measure .6 Ohm) and it fell on its face over 2000. Then I tried running a secondary with the (new) single coil to no avail either? Only the two original coils will let me get to 6000.
this is the module I purchased yesterday even after my other one tested good, it DID seem to make a difference by minimizing the miss. I was actually able to punch it and feel some torque where as before it would just crap out if I punched it.

that was my next thought. The pickup ohms out at 3.6 Kohm which appears to be in spec. And I set my gap at .014. Is there a specific reason it is suggested to use a plastic feeler guage other than that the pickup is magnetized?

I think today I am going to get a new battery, and try setting the star gap to about .010. I will also check the ground points again (they tested good once already) to see why I’m not seeing battery voltage at the +Ve side of the coil.

 

I always assumed....heh heh, danger word there.....that it was simply because you can't get an accurate 'feeling' from the feeler gauge if the feeler gauge is magnetically stuck to whatever it is you're trying to feel between!

Cheers
DD

 

With Doug there.

Most feeler gauge sets down here had a plastic 0.024 strip (Yellow were mine) as part of the pack, but they have now gone.

The magnetism gives a false feel, was the "blurb" back in the day.

 

I just did this yesterday with my steel feeler gauges. Since I cannot find a plastic one.

The pickup grabs the steel feeler gauge firmly so you really can't feel the friction. I used the loosened pickup to press against the gauge and thus the star wheel while rotating the centrifugal advance to pass a star wheel peek across the gauge, tightening it while at it's TDC. visual inspection with a flashlight showed a snug fit against the gauge and I called it done.

Fortunate random placement of the dizzy such that the advance moved across the pickup.

 

My Typo above:


The 0.024 should read 0.014.

 

Had my battery tested today and it appears that it is good. However when I turn it over, it really lugs bad like there is not enough juice in the battery? It’s a 935CA and 750 CCA. I don’t really know what else would cause this? Starter? Key switch? I’m fairly certain this is all electrical related at this point, so now I need to figure out why the car won’t rev over 3000 with the new single coil measuring .6 Ohm and will only rev (but still misses) with two .6 Ohm coils? Thoughts?

 

A bad/dirty connection from the battery to the engine bay will cause this. I would be checking the main + post in the engine bay and clean it and make sure it's tight when you're finished.

 

1. Yup,. it all begins with clean, tighten and lube the battery cables all of them, at each end.


2. Me and feeler gauges never got along all that well. The friction drag is quite subjective. It wasn't til ROTC that I found the answer!!! A go/no go guage for setting the head space on a Browning 50 Cal. Machine gun.


3. Make a .014 plastic guage. Select a chunk of whatever. Measure with a micrometer nd sand to size.


4. Or very rough old tech. A match book cover cardboard is about .024. Used from time to time to set ignition points!!


5. I was messing with of my B&S one lung yard machine motors. I needed to set the pickup gap on it's flywheel magneto. Magnets negated a "normal" feeler guage, of which I have several. I set it with a sheet of typewriter paper. Size ?. But, looked good. Worked, engine fired. Ran great...


Carl

 

Update:
battery tested good, car still seems to turn over very slow. However, after running for 15 min or so, I can read a voltage drop in the battery. While running I read 11.64 volts at the battery, after 15 min or so, I read 11.53 volts and it continues to go down. I assume this means the alternator is not working. Would running off the battery only cause the problems I am seeing?

 

11 volts sounds like the regulator in the alternator is bad. These can fail due to a build up of oil and dirt.

 

I reckon you are well on the money here.

That voltage is really too low to keep ALL that electrickery on the boil.

Sort that alternator, then re-establish the fault once you are reading 13.1+ with the engine running.

 

I had similar symptoms a while back: low voltage at the battery (~11.6~11.8V ish) with engine running. But I also had the alternator lamp on on the dash.

After replacing the alternator, lamp is off and now I am getting 13.5V with engine running/idling

 

After looking into this alternator issue, I’ve noticed that there was not a wire plugged into the push on connector at the back of the alternator (the excite wire). And then noticed a brown wire attached to the right side fender well with the correct push on connector. I assumed this was the excite wire from the lamp in the dash and plugged this into the push on connector on the alternator. There was not a change in voltage. So my question is, how can I test this excite wire to see if it is indeed supplying the alternator with voltage to start the charging process? I’m thinking key on, should have battery voltage on excite wire? If not, check to see if dash light is burnt out?

 

The excite wire goes to the alternator lamp on the dash, the current draw from the bulb excites the alternator. The alternator will also excite if you rev the engine.

At 11 volts your alternator is most likely bad. If so I would recommend replacing it with a 115amp, the XJS should never have had the smaller alternator especially in the HE with far more electrics to drive.

 

I attempted to replace the unit (which tested bad) with the 115amp replacement, however, the bolt holes and shaft size are larger than the stock unit? The new alternator does not come with a pulley or cooling fins, so how do i replace the 80amp with a 115amp?