no juice to coil

[Richard]

Ok folks, this is what I have as an update:

Please look at the attached pix. This is on my 79 Traveler, new engine (about 50 hours of garage running), TQ, P/s. P/B, A/C, Tilt, TF 727, D44 front and back with TruTracs, Prestolite Disto with Pertronix I / Pertronix 1.5 ohm coil, timing at 10 degrees, vacuum at 18.
I installed a new rotor, cap, plugs, coil based on the above thread, previous discussion, and comments. The truck since installation has MAYBE 15 miles on it. WHAT GIVES? if you will look at the rotor, it looks fried! there has got to be something that is "cooking" the rotor like this. As I mentioned before, I am not an electrical genius. most of this stuff is pretty straightforward.

The Traveler starts right up and runs fine: for a while, then starts sputtering, similar to a bad carb adjustment. I am having a hard time understanding that it might be a gap issue with the rotor/cap, as mentioned above. Could it be the plug wires (resistance)? I am running MSD 8.5 superconductor wires that are (per vendor) RFI compliant. Is there something else that could be causing that much current/voltage to "cook" the rotor?

RE: the coil - it is a new Pertronix I, there 4 wires going to it - two from the Pertroinx, one to the tachometer, and one to the bulkhead. According to the shop manual, That's it.

Sorry to be a dunce, but this is really bothering me and I could really use the help.

Richard

 

[Richard]

Mr. Kenney:
re: your mention of the "phasing" issue. I am a bit stumped on how the disto gets out of phase, to begin with. I read the linked article and I am trying to understand. AS I have never seen this issue before, I am kind of lost. I am going to do the "hole in the disto cap thing" today and will report my findings. This issue is occurring on both of my Scouts the 77 and 79. The 77 is not so bad though. Both have Prestolite disto's.

 

[1975IH200]

Late comer here.

Two items:
#1 - do you have the correct distributor cap? Holley cap has female terminals and Prestolite cap has male terminals. I have not seen a photo of the cap/terminals. Can you provide a photo?

#2 - the PerTronix catalog, footnote 79 states "Not for use with solid core spark plug wires."
The MSD 8.5 Super Conductor plug wires state that they "each foot of finished wire includes 40 ft. of tightly wound copper for superior conductivity. This winding procedure, combined with a ferro-magnetic impregnated center core, produces an extremely effective Electro Magnetic Interference "choke." "

I suggest you check with PerTronix to see if these MSD plug wires are compatible with the PerTronix modules.

NAPA Distributor Cap p/n AL162 for Prestolite distributor photo below......

 

[Richard]

1975IH200:

yes to #1, I have the correct cap. I have run this Prestolite disto for 25 years with no problems. All of a sudden, I am having problems. Since I had all day to play with my toy, I decided to check the "phasing" issue as mentioned in the above thread. Yup, I do have an out-of-phase situation. The rotor is sparking between the #8 post and the one before it. CRAP! I do not know how this works or how it came to be, but it is there. Just out of curiosity, I move the disto one notch over to see if that would clear up the issue, NOT! So- I am stuck with this problem. I have to find a disto shop that does this kind of work. CRAP! My problem is that I have this very same issue on both of my Scouts, a 77 and a 79, both with Prestolites, both with Pertronix. CRAP!!!!!

#2, I did ask Pertronix this very question re: the MSD wires. They are ok to use. But I need to call them back in the morning re: clarify the MSD wires.

I am really stumped re: an out-of-phase disto. I just do not know what the hell is going on. The Prestolite disto is a very straightforward design. The entire shaft is one solid piece and the only movement is the center weights springs. I am totally out of my comfort zone as I do not know how to fix this.

Time for a few brews tonite.

On a positive note, My son got his Corbeau bucket seats and is installing them in the 77 Scout II. Word to the wise: the Corbeau seat with adapter slides raises the seat about 2 inches if not 3 inches. I'm 6'7" and he is 6'2". his head is not about one inch from the roof. Noy good! gotta either return them and put the original buckets back in, or get lower pedestals.

I will report on the Disto issue as I get it. Thanks all for the help!

Richard.

 

[1975IH200]

RE: "phasing".........I am not understanding how this became an issue.....or if it really is an issue in your case as nothing that affects phasing has been accomplished to your distributor(s).

There are 17 teeth on the distributor drive gear.
360° divided by 17 = 21.17°.
Therefore, one tooth rotation of the rotor shaft (with the distributor body lifted up just enough to allow this) will move the rotor 21.17°.
With any subsequent movement of the dizzy body, after reinstallation to the block surface, allows a large variation of static timing to the engine.

 

[Richard]

good morning, and thanks for the reply.

1 - this disto (Prestolite) is an original one and has not been touched inside, other than my cleaning it and making sure the springs, weights are freely moving. Checked for bushing wear, all good.
2 - the disto rotor only fits one way as it is notched to the disto shaft. I have also checked the disto caps, all are the same re: precise location of terminal posts.
3 - yesterday, thinking that I could move the disto forward/back one tooth on the shaft gear, I did that. No difference. Put back to original, 10 degrees. Starts right up and runs fine - until it starts sputtering (like a bad carb adjustment)
4 - The pertronix module and plate are a direct bolt in, there is no adjustment of the plate as it is secured by two screws from the side of the disto body. The only movement there is the vacuum advance when it kicks in. I checked that, and it moves freely as it should.
5 - Attached is a pic of the disto with Pertronix module.

yup, I am really, really stumped. What I am going to do is take out the Pertronix modules and reinstall them. Maybe I did something wrong, but I don't think so. I will report on progress.

Thanks

 

[Zaedster]

Sounds like too much resistance in your ignition system. I would question the plug wires. According to Ohm's Law, V=IR, more resistance with the same overall current flow equals more voltage. The "resister" in this case is the rotor. You will achieve higher voltage with higher resistance wires, which will then create more heat down the line.

Try some stock plug wires or an old set and see if your results change.

 

[Robert Kenney]

Please don't take the following as nasty, I need to say this, rotor phasing has nothing to do with anything outside of the distributor.
The burning is because the plastic is being burnt by the spark not having a straight line of sight path from the rotor to the cap post. Once the plastic becomes burnt it becomes low resistance and is then part of the path for the spark.

Richard, At idle how big is the gap from the rotor conductor to the cap conductor during your phasing test?
Is the vacuum can connected to manifold vac?
Was the vac advance connected for the phasing check?

 

[Robert Kenney]

More thought, the Pertronix Ignitor I is triggered by the magnetic part you slide over the shaft and place the rotor in to lock it in place , There are magnets molded in to the lower part that trigger a hall effect transistor. The hall effect transistors can be effected by outside magnetic fields. That being said.

What was the most recent thing you have added or modified on this engine before you began having issues?

 

[Richard]

Good morning all:

this is a 1979 Scout Traveler - 345, TQ, 727 TF, P/S, P/B, A/C, Tilt, D44 front and back with TruTracs, 2-inch lift, Firestone 33" A/T's.,
Running a Prestolite disto with a Ptron I and Ptron coil. Timing is at 10 degrees. vacuum is at 18 steady.

! - the position of the rotor during warm idle (with the vacuum advance disconnected) is right between the #8 post and #1. What I did also was pull out the disto and went one tooth over. Same issues, only different position.
2- I called pertronix and talked to their "tech" guys. I sent them the above pix as well. I asked about the MSD 8.5 Super Conductor plugs wires, they said that was not the issue. They are supposed to be discussing with the other "tech" guys at Pertronix. They are supposed to get back to me this week.
3 - I called MSD/Holley and asked about the RFI issues re: their plug wires. They stated that the wires that I have are not solid core and are RFI compliant.
4 - What I am going to do this weekend is this: I have a spare Prestolite disto. I am going to pull the one in the 79 and change over to the spare, then reinstall and see if the problem is the disto (being out of phase). I really don't understand the "phasing" issue, but if the issue still exists, then there is something else wrong. I can't see two disto's with the same problem.
5 - Re: the plug wires - I will change them to a stock set of original IHC plug wires (old school) that I have never used as I have 4 sets of them, but I don't see that as an issue, but it is worth a try.
6 - Re: any mods or additions to engine before I was having issues? I do not know as this engine was just started in January this year after sitting in my garage since 1987. I bought it new from IHC and has never run until January this year. When I got it running in January, I was just happy with it running! It starts up fine and runs real nice (sitting in my garage). I did not notice this issue until I had the same issue with my other Scout II (77 with Prestolite disto). Re: the thread above - I was having what I thought was carb issues (sluggish running, hard to start, poor mileage) I had the Holley 2bbl. rebuilt twice, switched to another Holley 2bb., but with same issues. When the 77 died on the freeway, out of curiosity, I pulled the disto cap and found a similar situation with rotor. I thought that maybe it was the Pertronix module going bad, so I bought another one, but a Ptron II. It was at this time (out of curiosity) that I checked the disto in my 79 Traveler. That is when I noticed the gray dust in the disto cap and the burnt rotor. The rotor was not as bad as the above pix, but it was never under a load in the garage. I swapped out a new cap and rotor to the 79 back in October.
Hell, I was just happy that I got the 79 running and out of the garage. When driving around the block a few times, it started missing. backfiring. so, I pulled back into my driveway - and here we are to the present.
7- I wish I could post some videos of the engine running here, but apparently that is not allowed.

Anyway, sorry to drag on so long - there it is. Thanks to all for the input and help. I will post as soon as I can with updates.

 

[FDChappie]

IIRC many posts back, you rebuilt this distributor do you still have the oem vac advance unit. The indexing is changed by moving the "breaker" plate in these distributors to advance/retard the spark. So so if the mechanical or vacuum advance is not correct it will affect the indexing.

 

[Robert Kenney]

One sure fire way to fix it,
The tab on the vac advance locates the cap I assume. Move/enlarge the slot in the cap so you can rotate the cap CCW?, to the correct position as indicated in your phasing test. Add material to the slot so it can't move. Test. The proper phasing is past the intended cap post at full retard and the same distance behind at full advance.

Also make sure there are not any contaminants on both the rotating trigger ring and the ignitor sensing face.

 

[Robert Kenney]

Oh and I called Pertronix a couple of months ago to ask if they had any issues with rotor phasing on their IH Ignitors. Explained your issue and the tech told me I did not have the distributor installed right and that a restab would correct it. Hung up on him after a brief attempt to explain to him how the phasing worked.

 

[Richard]

Mr. Kenney:
re: the vacuum advance rod is separate from the Cap and the cap is notched. There are also two clips that spring load the cap to the disto case. The breaker plate is not adjustable as it is held to the disto body by two screws. The only thing movable is the Ptron module plate (the plate above the breaker plate. That swivels with the vacuum advance in action. With the vacuum line disconnected, it does not move. Or, maybe I am not seeing your explanation correctly.

Re: your call to Pertronix - HAH!

 

[1975IH200]

Do you have the required ,010” air gap between the P-tron module and the magnet ring?

 

[1975IH200]

The distributor fires every 45° of rotor rotation.
One tooth adjustment on the shaft is 21°
So, "restabbing" the distributor one tooth will move the rotor 21°.
If the rotor moved to the same position, but between the next set of contacts, as you stated, then you moved it two teeth.
Try moving the rotor shaft again, ie. restabbing one tooth.

 

[Richard]

Re: the 10-degree gap - there is no adjustment between the magnet ring and the Ptron module. The module is set by the two screws holding it down. Re: the restabbing - I guess what I meant to say was that the rotor was in the same position between the #8 and #1 post of the cap.

 

[Richard]

All:
I sincerely appreciate the input, comments, and advice. I know there is an explanation for my issues, just have to keep at it. Thanks all, will post up as soon as I can.

Richard

 

[1975IH200]

Re: the 10-degree gap - there is no adjustment between the magnet ring and the Ptron module. The module is set by the two screws holding it down. Re: the restabbing - I guess what I meant to say was that the rotor was in the same position between the #8 and #1 post of the cap.

There should be adjustment provided by one of the screws.
Gap should be .010”.
What is your gap?

I don’t understand why you can’t restab and get the rotor movement of 21*.
Are you lifting the dizzy body up high enough to disengage the rotor shaft/gear and moving the rotor/shaft one tooth?

 

[Robert Kenney]

Mr. Kenney:
re: the vacuum advance rod is separate from the Cap and the cap is notched. There are also two clips that spring load the cap to the disto case. The breaker plate is not adjustable as it is held to the disto body by two screws. The only thing movable is the Ptron module plate (the plate above the breaker plate. That swivels with the vacuum advance in action. With the vacuum line disconnected, it does not move. Or, maybe I am not seeing your explanation correctly.

Re: your call to Pertronix - HAH!

You miss understood me. The vac advance base has a tab that sticks up that locates the clocking of the cap, right? (image)

The cap slot can be opened up to allow the cap to be reclocked to align with your existing rotor phasing. The spring clips might be strained a little.