Mallory ignition questions, Partial success! Options

[jeffdon]

Okay, partial success!!!

We got out of a training class way early today, so I cam home, rewired my ignition, and collected some more data.

First off, OMFG! That rewire changed the cars starting habits like you would not believe! The "pump the gas twice, crank for 20 seconds until it fires while playing with the throttle" was gone. I started my usual routine and the engine caught so fast I turned off the car in surprise! If the engine stalled I could restart it by just reaching in the window and turning the key. I could almost never do that before. I suspect this will be a major change for the best.

But, it still idled crapily and would sputter and die unless I gave it more gas. You can hear the misfires. So I got out my timing light to check spark on the different leads. I held the timing light on each lead for ~ a minute and just watched the flashes while the engine idled.

My idle for tonight's experiment was set ~1000 rpm.

Plug wire 1 was a metronome. It never skipped a beat that I saw.

Plug 2, 3, and 4 all had seemingly random misfire events. When the engine would sputter you could see that it was not getting spark on that cycle. Most of the time they would fire, but sometimes they simply would not.

However, when I added even just a little more gas, the misfires seemed to go away. Its like the timing got noticeably better around 1400-1600 RPM.

The plugs are new - under 1 hour run time on them. The MSD spiral wound wires are ~1.5 years old - but the fact that the spark gets better as the engine starts to advance leas me to believe that the issue may be with the Mallory's initial timing set before it starts its mechanical advance. I did not check where it was timing in at idle. If I can get time again tonight I will run out and check that.

Any ideas?

Zach

Hey Zach, what do you set your timing for at higher RPMS? 3k-3.2k?

[VaccaRabite]

Okay, I just tested my timing at idle (1000 rpm) and 4K.
At idle, it is set at 8 degrees BTDC.
At 4K it is set to 28 degrees BTDC.

This would indicate that I am 4 degrees retarded at idle, and may be my issue.
Also, at idle the timing mark seemed to dance around just a little bit. Less then a degree to be sure, never out of sight. At higher RPM, it was very steady.


Zach

[Gint]

Curious... what exactly did you rewire that gave such an initial improvement? Just took the ballast resistor out? Or was there more?

[VaccaRabite]

Curious... what exactly did you rewire that gave such an initial improvement? Just took the ballast resistor out? Or was there more?

I just took out the ballast resistor. After reading the instructions I kept the resister in line from the ignition on wire to the coil +. But I took the resister out of the circuit entirely from the coil to the dizzy. Had to crimp on a new end to do this.

The difference in performance was night and day from this 30 minutes of work.

Zach

[nathansnathan]

Sounds like you're advance is set to 20 degrees. I've heard the proper is 16 degrees advance, 12 it idle, 28 all the way in?

[VaccaRabite]

Yes. I need to reset the static time. I am really hopeful that this will solve all of my sputtering issues, and I can get back to the real test of finding the best jetting for my motor. I am guessing that when I fix my ignition, all my current jetting info is going to need to be re-examined.

Zach

[VaccaRabite]

I FINALLY fixed my static time.

I used the 16 degree key to set timing. That was kind of a chore, and I can see how the PO goofed it. Its probably easier with the dizzy out of the car, but I was being stubborn. It seems like you need two keys to do it, or one key and a lock to keep the dizzy in place while you torque down the set screws.

I retimed the car and extra initial advance certainly helped, but at idle I can still hear the car missing.

Cyl 1 is a metronome. It never misses.
Cyl 2 had an occasional miss. 10 missfired over the course of a minute.
Cyl 3 was missing often. Over my 60 second count, it missed enough that I lost count. I would guess that 1 of every 10 beats it missed.
Cyl 4 was missing too. More then Cyl 2 and less then Cyl 3.

I am going to try a valve adjustment maybe Friday... When in doubt, check the basics. But I don't expect to find any surprises there from when I set it in the spring.

If that does not solve the issue, I am going to move to a bigger coil then the blue one.

The good news if that during the 1/2 an hour or so that I was dicking with the car after setting the timing, it did not try and die once. That is an improvement. But I need to get those misfires under control.

Zach

[MarkV]

I am running a 2056 w/ delorto carbs and a mallory distributor.

I put a Pertronix II kit in my mallory distributor and am running the Pertonix .6 ohm coil. The car starts and idles better with the .6 ohm coil. I ran it for a while with points and a resistor on the coil but you can notice a big difference without the resistor.

Are you sure your miss isn't coming from a bad cap or rotor?

[VaccaRabite]

My mallory is already electronic - no points.

Is there a way to test the cap and rotor? They don't look damaged...

Zach

[MarkV]

A Pertronix II will work with a .6 ohm coil, a Unilite won't tolerate that. If you have to run a resistor why upgrade the coil.

If the cap is real bad you can see stray arcing if you look at the distributor with the car running in the dark.

[curt914]

Hi Zach

Been following your thread and waiting to see how things turn out
as I pretty much have the same setup.

Wondering if your misfire is due to the spark plug wires "leaking" somewhere along the way.
Maybe to ground or to another spark plug wire?

Also, could it be the cap (near the spark plug towers) leaking to the tin nearby.

As you know, you have to pound the tin into submission just to get the distributor in to begin with.

After round 1 with the tin, I repainted it a time or two in the area of the distributor and
also put a layer or two of electical tape on the tin right where the distributor cap is very close to the tin.

Are you sure the spark plug wires are completely seated all the way down in the distributor spark towers?
Its such a tight fit to get the wire and the boots all the way down and it would be a short hop for high voltage to find the tin (ground).

Well, good luck, hope you get to the bottom of it. (IMG:style_emoticons/default/smile.gif)

Curt

[VaccaRabite]

Its not the tin. My dizzy is 180 off, so the #1 lead is where the #3 lead should be (right against the tin.) #1 is the cylinder that never misses a beat.

I am going to try a new cap, and then I am going to move to a bigger coil. The car always had a miss at idle, and I have changed wires so that counts out wires. Changed plugs, so that counts out plugs. That leaves the cap and rotor. They LOOK great, but who knows? So I will try them next.

Zach

[FourBlades]

Any chance you are running rich at idle? There was a long thread on the samba
about how that can make it harder to ignite the mix.

John

[FlatIV]

You can run it at night in a dark area and see if the the wires or coil are arcing.

Andrew

[MarkV]

(IMG:style_emoticons/default/agree.gif)

[orange914]

(IMG:style_emoticons/default/agree.gif)

(IMG:style_emoticons/default/agree.gif)
+ mist it with a hand spray pump with water

cool night light show. you'd be surprised how mch even great wire leak sumptin'

[timothy_nd28]

What was the end result, or are you living with this rough idle?

[VaccaRabite]

Microsquirt with crank fired ignition.
Not done yet, but so not living with craptastic idle.

[timothy_nd28]

Are you willing to part ways with your Mallory unilite? (IMG:style_emoticons/default/idea.gif)

[EdwardBlume]

Zach, did you ever get this resolved? (IMG:style_emoticons/default/popcorn[1].gif)