No Advance at Crank Pulley, Table Shows Advance

[MegaSlant6]

Hello,

the ignition is:
MS3 Pro + MSD 6A + Lean Burn Distributor

was running on MS3 fuel control only, swapped the wires around today to also get MS3 Ignition control
pin 6 CKP+ to the white distributor + wire
pin 15 CKP- to the black distributor - wire
pin 24 tach out to the MSD white wire

the motor started and with the input table set to Fixed Advance and 10 degrees of timing set at the distributor and in the MS input input table, observed engine timing with a standard timing light. The timing was at 10 degrees, but was not stable, bounced randomly from maybe 8 to 18 degrees per the strobe light. I had started and observed the timing at the crank pulley with the lean burn distributor installed, prior to wiring in the MS3 for ignition control and the timing was very stable at 10 degrees BTDC.

I then open the input table and selected Use Table, and started the motor, the table responded showing the ignition advancing to the values in the table, maybe 34 degrees at 2000 RPM. However when I observe actual ignition timing at the crank pulley, the strobe light shows the same random timing bouncing from 8 to maybe 18 degrees at 2000+ RPM.

so the table shows ignition advance, but I an not getting that at the motor,,
also the timing at the crank pulley is not stable.
what's wrong?

also, the CKP+ and CKP - wires are both contained in one shielded wire bundle, should I have the terminal end of the wire shielding grounded or is it already grounded at the connector at the MS3 Pro end?

I have a MSQ saved and will attach.

Turner Studio is MSv3.0.28
Firmware is MS3 release 1.3.4

thanks

[wes kiser]

In addition to properly selecting "tacho out" for your main ignition out, you also have the actual tachometer output turned "on," and this set to "tacho out" as well. I would have guessed this would be a configuration error.

Perhaps try turning off the tachometer output found in Basic/Load settings, burn, and and power cycle.

[MegaSlant6]

I will try switching it off as described, maybe tomorrow before I can get back out to the garrage.

yes I did have the #24 wire signaling an external tachometer when I was running fuel only and the tach worked fine.

I disconnected the external tach when I rerouted the #24 wire to the MSD box.

[MegaSlant6]

Hello,

I did as mentioned above, under basic load settings turned the Tacho to off,
burn, shutdown,,

not good, very hard to start, when started backfire out exhaust, would not idle without feathering throttle

re set Tacho to on, burn and re power, got a MS error message that said conflict, "Tacho set to spark..."

re set Tacho to off, burn and re power and then also re set Ignition Input Capture from rising edge to falling edge..

BINGO,, re start was good, timing mark at the crank damper is much more stable at idle and the timing at the crank damper
increases smoothly with rpms.
so it appears to be fixed by:
1) setting Load setting Tacho to off
2) setting Ignition Input Capture to falling edge

,, what I don't understand is with the #24 Tacho wire is set to off, how is it controlling anything?
there is a list of items in the drop down list, Tacho is only one possible choice, should one of those be selected and set to on for this ignition install?

[wes kiser]

The "tach output" function is not necessarily the tacho wire. It can be assigned to a variety of different outputs. You had two software functions (main spark output, and the tach outpout) assigned to the same wire.

Not all installs necessarily need the tach output function. Generally with single coil setups, the coil negative or the tach output from the ignition box (if it has one) can be used. On waste spark or COP setups, generally the ECU is required to drive the tach. That is what this feature is for.

Is your tachometer connected and working?

Also, now that it appears to be "doing what its told," be sure to set "Fixed advance" to a reasonable value, and rev the engine up to verify actual timing equals commanded timing, and it is stable as you rev the engine.

[MegaSlant6]

Hello,

wired the Autometer Tach to the grey wire out of the MSD6AL box

and the tach works fine, it reads the same as the tach that shows on my laptop when it is connected to the MS3Pro system

however, all is not well,,
1) when the 'Fixed Advance' tab is selected, on the Ignition settings menu,, at idle the ignition timing at the damper is with a degree or two of the 9 degrees I have inputted in to the
timing for fixed advance, however as I increase motor RPMs the timing light shows the timing at the damper increasing with RPM's. Total timing gets beyond the timing tab quickly, guessing it is going to 35 degrees at 3000 RPM.

2) When the 'Use Table' tab is selected, and I set the entire table to 12degrees,, at idle the RPM is about 12 degrees, however as RPM increases, the timing at the damper increases to about 35 degrees, just like when it is set on fixed.

I know that I have a locked distributor installed, no springs, no weights, just a shaft from the cam drive gear to the rotor.

I will pull it and disassemble it tomorrow and post a photo,

[billr]

The easy way to "lock" a dizzy is to remove the weights but leave in the springs. Since you have the springs out, too, then I gotta ask if you have some other way that is locking it.

With the Pro + MSD + dizzy, you have "too many cooks in the kitchen" for my tastes. Consider adding a simple missing-tooth wheel and three wasted-spark coils. You will have a simpler and more reliable system, with much better timing accuracy.

[MegaSlant6]

Hey billr

the distributor is a chrysler lean burn distributor,, it is a 'locked' distributor from the factory,
no weighs, no springs, no vacuum advance

[billr]

OK, I misunderstood; I thought you took out the springs and weights. Does the Pro have a built-in driver for a single coil, like the BIP373 that is standard in the regular MS3? If so, I would try using that and getting the MSD box out of the picture.

[Paul_VR6]

No driver in a 3 pro, usually timing drift in locked mode is the output is set to the wrong edge. Double check your settings with the manual.

[MegaSlant6]

Hey Paul,,

the MS3 Pro manual mentions that a basic trigger such as a lean burn distributor can be used, but other than that has no other setting info,
I did find the DIYAutotune post linked below on the internet that addresses MS I and MS II products and lean burn distributors/vintage mopar ignitions

https://www.diyautotune.com/support/tec ... ignitions/

however the article appears to predate MS3 Pro so it is not a direct 'use these settings' situation.
I have applied all that does correlate,
Ignition capture on falling edge
Spark output going high
nominal dwell 3ms
as well as the trigger off set angle set up..

and concerning the MSD box,, initially, while having the MS3Pro control fuel only, the ignition was being ran by a 7 pin HEI module,
I swapped in the MSD 6A box, just to see what it would do and got a measurable improvement at the drag strip, so I would like to keep the
MSD box in the picture.

DIY has a booth at the PRI show in Indy and I plan to be there this Thursday
I should be able to get a lead on resolution then.

[billr]

Your choice on the MSD, of course. I can believe it is an improvement over the HEI, but doubt it is better than (even as good as?) wasted-spark or COP.

Timing accuracy will never be as good with a dizzy as the trigger, even if you modify it with a higher tooth-count wheel under the cap, so I still urge you to consider the upgrade to a real crank wheel.

[MegaSlant6]

Hey billr

Timing accuracy will never be as good with a dizzy as the trigge

who does not know that?

the current hardware set up is the way the motor will be for now, if you would read my posts you would see the timing change that I am working to resolve is more that a drift of a few degrees.

don't take this the wrong way, if all you can do is recommend hardware changes, feel free to ignore this thread.

thanks

[jsmcortina]

Your hardware combination should be capable of working ok.

So just to recap, originally on the ignition side you had:
Dizzy VR pickup -> MSD -> Coil

Now you have:
Dizzy VR pickup -> MS3-Pro -> MSD -> Coil

No doubt some of this has been covered but, I'll repeat for clarity.
1. the dizzy must be locked such that at all revs, the signal to the ECU happens at the same engine angle with as little slop as possible.
2. if the ignition capture is set backwards, the timing will be unstable
3. if the spark output polarity is set backwards, the timing can be unstable

Persist with "Fixed Timing" until it matches up without bouncing around.
I see in your MSQ that you have standard dwell set, good. You can test #3 above by adjusting the dwell.
MSD boxes don't actually care about the "dwell" on the white wire input. If you adjust the dwell from 3 to 4ms and the timing makes a big move, that your spark output polarity is backwards. If the timing is unchanged, then good.

James

[billr]

Sorry to annoy you. Good luck and goodbye.

[MegaSlant6]

Hello James and thanks for the reply

I was in the garage most of the day today and just now saw your post
"adjust the dwell from 3 to 4ms and the timing makes a big move'
so I have not tried that, I will at my first opportunity.

Today I pulled the distributor and went through the whole initial timing set up, basically what I did is
1) aligned the crank damper timing mark with 9 degree BTDC with #1 cylinder ready to fire

2) installed the locked lean burn distributor so that the reluctor tip is pointed directly at the distributor's pick up coil center pad and the rotor is aligned with the #1 spark plug cap terminal. I have cut the #1 spark plug wire post off an old distributor cap, so this is easy to verify.

3) I then started the motor and with the ignition setting set to "fixed timing' worked the Timing Wizzard to get the damper timing mark to match the 9 degrees that I have inputted as my initial timing. I ended up with 23.3 degrees of off set in the Timing Wizard to get the timing at the crank damper to match the inputted timing setting.

Question is 23.3 degrees of off set an indication that my initial set up with the distributor is off by 23 degrees? Should I pull the distributor an try to get it closer?

4) with the timing still set to 'fixed timing' and the timing light shining on the damper, I rev'd the engine to about 3000 RPM, the timing on the damper moved forward in a very smooth fashion to approximately 25 to 30 degrees, my timing tab stops at 20 so the increase is an estimate. The timing increase is very smooth, not jumpy or erratic.
Question with the timing set to 'fixed timing' should the timing increase with RPM? If not how do I resolve this?

5) re set the entire timing table to 15 degrees , and re set the timing selector to "use table' did a burn and save,,started the motor and checked the timing at the damper with a timing light. The timing was approximately 15 degrees, some movement from 13 to 16 at idle. Rev'd the motor to approximately 3000 RPM and as with 'fixed timing' the timing at the damper increased to 30 to 35 degrees, again the increase was very smooth with RPM. Reduce the RPM and the damper timing would smoothly fall back to the 15 degrees with some movement, increase the RPM's and it goes smoothly back up to 30 to 35 degrees advanced.
Question with the timing table set to 15 degrees in every cell, why would the timing increase beyond the initial 15 degrees with RPM? How do I resolve this?

a few notes:
6) concerning the jumpyness of the timing mark,, it is jumpy only at idle,It is has the same jumpyness with fixed or table timing, immediately off idle the timing light under strobe smooths out, The timing gears and chain are premium parts, the timing was rock steady prior to this recent ignition system swap
7) the motor starts ok, after a crank or two,It fired on the initial hit of the key prior to this change over
items 6 and 7 seems to be an indication that all is not yet optimized

thanks

[jsmcortina]

Two issues I see immediately there.

1. An ignition offset of around 20 degrees isn't going to work. You are going to have to re-phase your distributor.
This is covered in the manual. Please read the entire section, starting here: http://www.msextra.com/doc/pdf/html/MS3 ... 4-117.html

2. Fixed timing is just an easier version of setting the whole table to one angle.
No, the timing should not move. See points 1,2,3 in my previous message.

James

[MegaSlant6]

re-phase your distributor.

will do, probably Saturday / Sunday before I can get any quality garage time

Much Thanks

[MegaSlant6]

re phase the distributor

when you say re phase,, is that as simple as: loosening the clamp that prevents the distributor body from rotating and leaving the distributor engaged with the cam gear and rolling the body of the distributor clockwise approximately 10 degrees?

what would that change??? as the distributor pick up coil is attached to a plate that is attached to the distributor body and the distributor cap is attached to the distributor body... The rotor and reluctor would remain stationary, but the distributor pick up coil and the distributor cap would both rotate forward by 10 degrees,,delaying spark initiation from the reluctor - distributor pick up coil and transfer from the rotor to the cap and spark plug wire by 10 degrees,,

is that what I an needing to do?

[jsmcortina]

re phase the distributor

when you say re phase,, is that as simple as: loosening the clamp

No, it's a lot more difficult than that. You have to change the angular relationship between the rotor arm and the trigger pickup.
e.g. cut and reweld the shaft or drill new holes in the baseplate to move the pickup around by 10 degrees.

James