Distributor help!***Mission Accomplished***

[WizeOne]

Re: Distributor help!

Re: Distributor help!

Hey Wize, Can't leave us hangin like this, Did you get it sorted out?

NO! I reconfigured the distributor to the best of my understaning and reinstalled it. Now I have no spark at all. I think it is an issue with my MSD6a ignition. Hopefully this weekend I will by-pass it and give it a whirl. I'll keep you all posted.

 

[dolluper]

Re: Distributor help!

Re: Distributor help!

Hummm check
http://www.msdignition.com/page.aspx?id=3206

 

[WizeOne]

Re: Distributor help!

Re: Distributor help!

Hummm check
http://www.msdignition.com/page.aspx?id=3206

Thanks dolluper. That is the proceedure I will use tomorrow. It will also be easy enough to re-hook up the Pertronix as a stand alone and test that as well.

While working on the distributor, I accidently knocked the pertronix plate off of the workbench onto the concrete floor. I called them today to ask if that was likely to have damaged the ignitor. They strongly claim it would not have. Tomorrow we will see.

 

[dolluper]

Re: Distributor help!

Re: Distributor help!

Got her dialed in yet.....make sure the air gap is set right eh

 

[WizeOne]

Re: Distributor help!

Re: Distributor help!

Got her dialed in yet.....make sure the air gap is set right eh

The pertronix passed the bench test, dolluper but failed to produce a spark once the distrib was installed. I'm going to call Pertronix again tomorrow to find out what is going on.

If what you mean by 'air gap' is the distance between the magnet ring and the module, it is pre-set on mine as the Pertronix replaces the entire old point plate. It is however a question as the gap on this unit is many times greater the the gap on another set up I have, where the module sits on a base that screws to the point plate and is therefore adjustable. That kit came with a .030 guage to set the distance. I'll bet my boat unit is near .125.

I've got the MSD totally wired out of the system now and it passed it's diagnostic test with flying colors. So it is down to the Pertronix.

 

[dolluper]

Re: Distributor help!

Re: Distributor help!

Ask them the air gap setting for your app.....also make sure you haven't got some grease on the mods eye.....btdt

 

[WizeOne]

Re: Distributor help!

Re: Distributor help!

Ask them the air gap setting for your app.....also make sure you haven't got some grease on the mods eye.....btdt

dolluper, as it turns out, Pertronix technical is semi worthless. They tell me one time if the top of the magnet band is above the top of the module, it's no good. As I raised my distrib shaft, that put the top of the magnet band about .060 above the top of the module. The next call, they seem to think that is no biggy.

Today I called with the results of my bench test. They said "oh, that test is only for the Pertronix I, it does not work for the Pertronix II. (no other method offered) Then I asked about the air gap. They said it should be between .010 and .060. So I told them that my factory fixed air gap was .090. They had nothing to say. They also had no response as to whether a combination of magnet band height and excessive airgap(by their claim) could result in no spark.

They also could not/would not speculate on why I had the late firing phasing issue, which in part started this whole issue.

So now I have popped the rivits on the module, moved it inward by .060ish and placed some .060ish washers under it to raise it back up to the relative pre-shaft raise position.

Tomorrow, maybe, I will reinstall it all and see if I get a spark or if the module is shot.

It is extremely aggravating that I cannot get hard, cold design parameters from them.

 

[dolluper]

Re: Distributor help!

Re: Distributor help!

They gave you quite the range on the air gap.....your going to be playing more.....but what the heck your learning lots....don't discount the coil as I said before pertronic is real fussey on coil apps

 

[dolluper]

Re: Distributor help!

Re: Distributor help!

check your pm's you have mail

 

[WizeOne]

Mission Accomplished!!!

Mission Accomplished!!!

...just about wore out every thread in the poor distributor. I also had the Pertronix module rivited and unrivited so many times I thought I would wear out all the rivit holes.

...but it is done. I remade the module spacer with a solid piece of .061 aluminum sheet and gooped it up with computer chip thermo-mastic heat transfer compound. I checked and rechecked the module clearance to the magnet ring so that it ended up at about .030, down from the original .090. That is the same dimension as was perscribed for my adjustable Mustang Pertronix module.

Once done, I fired it up (on Pertronix only, no MSD) and the rotor was firing smack dab in the middle of the #1 cap cylinder stud. The motor seemed to idle smoother than it ever has. (albiet, a little lumpy compared to the stock marine cam) Just sufficient to beat the snot out of Tail Gunner's scow.

The above, of course, was in addition to the earlier work of having raised the distributor shaft by .080 so that the rotor tip was adjacent to the cap cylinder studs, not .090 below the bottom tip of those contacts.

Now I am wondering what I will think about as I drive down the highway in the course of my daily vocation.

Thanks all, for your inputs. It definitely makes me want to make a sacrificial dizzy cap for everything I own, to see where that rotor is and where it is firing. It is obvious, by my experience, you can not rely on a manufacturer or possibly in some cases aftermarket component suppliers, ie, Pertronix and the Napa/Elkin aftermarket distributor cap and rotor.

 

[NoKlu]

Re: Distributor help!***Mission Accomplished***

Glad to here you got it solved Wize. I think i'd be buildin a couple of extra parts for your future tuneups while this stuff is fresh in your mind.

 

[WizeOne]

Re: Distributor help!***Mission Accomplished***

Glad to here you got it solved Wize. I think i'd be buildin a couple of extra parts for your future tuneups while this stuff is fresh in your mind.

Precisely NoKlu. If my Pertonix ever died, I'd have to duplicate the positioning of the module on the plate, both lateral and radially. I'm hoping for a long life of that module so I don't have to deal with it.

I do keep the original point plate (complete with points and condensor) in the glove box. If I ever had to reinstall it in the field, my timing would be way off but it would hopefully get me home.

Looking back, I attribute my series of issues to dimensionally incorrect aftermarket distributor cap and rotor AND to an incorrectly phased set up for the Pertronix ignitor. Both of these things would never have been discovered by your typical mechanic who I might have engaged to deal with my running issues.

 

[MikDee]

Re: Distributor help!

Re: Distributor help!

This is Not New to me, being the tinkerer that I am! I've seen this happen, apparently it's tolerance in machining, & design, or overtolerance! Many years ago I had a Chevy V8 points distributor that had this same mismatch problem, actually I noticed it before electronic igniton was even introduced in 1974 for GM. Just Like You, (I cut away part of the distributor cap) and found that For the high spot on the cam, rotor, & cap all to align, the breaker plate had to be moved forward a little I solved it by putting a bolt behind the vacuum advance mechanism as a spacer. I then realized it was an issue with every single Chevy V8 distributor and who knows what other type, or brand of distributors are, or were affected?

This mismatch seems to me to be an overwhelming, all too common an issue, going on forever!, and I gave up trying to fix it yrs ago, just accepting it as is. "Don't fix it if it ain't broke!"

By the way, this was a standard black orig. equip. AC Delco dist. cap. Once I got the breaker plate lined up, with the bolt behind the vacuum advance arm, the engine ran better! Then I took the vacuum hose off, and disabled the vacuum advance and, put an aftermarket advance kit in with lighter weights, & springs, and set my initial static timing at 10*, with a total timing at 3000 rpm and it was fine!

I'm glad you finally got it worked out, but it sounds like quite a hassle

 

[dolluper]

Re: Distributor help!

Re: Distributor help!

Both of these things would never have been discovered by your typical mechanic who I might have engaged to deal with my running issues...Hummm I think I would've charged you an hour or so LOL's Glad to hear she's dialed in the drop from 90 to 30 by my calc would decrease the dwell about 1 1/2 degrees up to 2 degrees .....I taught 45 would've been on the money

 

[WizeOne]

Re: Distributor help!

Re: Distributor help!

....Glad to hear she's dialed in the drop from 90 to 30 by my calc would decrease the dwell about 1 1/2 degrees up to 2 degrees .....I taught 45 would've been on the money...

I thought I had a decent grasp of 'dwell' as it applied to points, ie, the amount of time the points remained opened (or closed) as a function of the 'gap' setting.

I don't see how that translates to a virtual on/off switch that is seemingly unaffected by the mechanical limitations that swinging points represent.

I did discover that the 'air gap' did affect the phasing. I originally redrilled the new module plate holes when the air gap was at .090. Once I closed the gap down to the .030, I had to elongate those new holes and reposition the plate to re-adjust the phasing again.

Although it would be a PITA to readjust the airgap, I can do it because I slotted the module mounting holes. It would be a matter of drilling the rivits and moving the module back. The PITA comes in due to a lack of an absolute reference point once the plate is out of the distrib and away from the fixed magnet ring on the rotor shaft. I would have to do it with scribed reference lines on the plate itself.

As to the ultimate airgap dimension, I did set it on .030 because that is what Pertronix perscribed for the adjustable module on my similar (289) Mustang motor.

Dolluper, help me understand 'dwell' as it relates to this hall effect system that simply produces a switched blip as the magnet passes the sweet spot on the module. There is no equivalant here of a swinging point arm that would translate into to time open or closed via a larger or smaller gap setting.

If, in fact, dwell applies to an on/off amplified signal switch, that should show up on an engine scope shouldn't it? I believe that engine specs specify an ideal dwell setting for a given motor?

EDIT: I did look at the manual and a distributor diagram did show how the 'airgap' distance would affect the travel time between the trigger points. As the gap increased, the arc length between magnets (cam high points) increased, thereby the firing position of the rotor would change. This explains why I had to readjust my phasing when I closed the airgap from .090 down to .030.

The manual showed a dwell of .31 deg for my series of engines. It showed a point gap of .019. I guess as the gap setting decreased, the dwell would increase. The manual also shows an "MFD." figure of .21-.25. I do not have a clue as to what that is and the manual does not explain it.

I have an old Craftsman analogue engine analyzer. I wonder if it will work with the Pertronix ignitor. I'm sure it has a dwell function on it.

 

[WizeOne]

Re: Distributor help!

Re: Distributor help!

....but it sounds like quite a hassle

Indeed it has been MD, but at the same time, quite the learning experience for a novice. Now if only I could expend that much effort and energy in my primary vocational endeavors.:redface:

 

[JustJason]

Re: Distributor help!

Re: Distributor help!

Both of these things would never have been discovered by your typical mechanic who I might have engaged to deal with my running issues.

I doubt that. I fix alot of ignitions systems... and a pickup failure on TB4's (especially the old design) is fairly common. It's also common to find reluctors in all sorts of different conditions (bent to hell) because everyone has had their hands in it before I see it.

Back on nov 3rd i said.

or a late trigger telling the coil to fire late

Well there was your problem, and you finally found it. Air gaps are a common check on any hall effect sensor (colapsing magnetic field). ignition pickups, CKPs, CMPs.... are all hall effect sensors, and they all have a realitive reluctor.
You were definitely overthinking this whole thing.

 

[WizeOne]

Re: Distributor help!

Re: Distributor help!

..Well there was your problem, and you finally found it. Air gaps are a common check on any hall effect sensor (colapsing magnetic field). ignition pickups, CKPs, CMPs.... are all hall effect sensors, and they all have a realitive reluctor.
You were definitely overthinking this whole thing.

Overthinking, probably. Considering my near total ignorance on all matters ignition, it just took me time to put all the understanding together, but don't forget, this was a two part problem. The other part was a rotor that was running .092 below the bottom of the cap cylinder terminal studs.

 

[Tail_Gunner]

Re: Distributor help!***Mission Accomplished***

Man i couldnt follow this thread anymore......Good to see you get that old ford runnin..Now get that bathtub you call a boat in the water and if it still float's ill be pourn a can of whoop A@@ down that old tub....

 

[WizeOne]

Re: Distributor help!***Mission Accomplished***

...ill be pourn a can of whoop A@@ down that old tub....

Gonna be pretty tough to do with that monster hitting on all eight.

btw, better get those scows of yours winterized. Had a big layer of ice on the top of the kiddy pool/dog foot wash pool, this morning.