Graham Paige Timing Woes

[GrahamPaige29]

Hi guys.  I finally got my 1929G Graham Paige model 612 running thanks to a carb rebuild.  But now I'm having some other issues with what I can only assume is the timing.  I bought a timing light and hooked the inductor to number 1 spark plug.  When the car was idling away, the timing spot on my flywheel marked "SP FA" which I assume is "spark, full advance" was lit up by multiple flashes from the timing gun.  I made a video that shows the car idling and a close up of the timing mark lit up on the flywheel.  If you look near the end of the video, the mark (highlighted by a piece of green masking tape) is wandering all over the place.  I don't get it.  Is my timing gun flashing multiple times and at the wrong moments or is the timing actually "off".  I assume the timing is off because I'm getting a lot of shaking of the car and funny burping/almost backfiring noises.  

 

Here's a link to the youtube video that shows the issue...

 

https://youtu.be/rVflB9d_9Qc

 

I'm wondering if it's an issue with the centrifugal advance on the distributer going wrong.  I can't figure out what else it could be.  No matter how carefully I adjust the distributer head back and forth, the light continues to dance around the mark flashing multiple times.

 

You guys ever experienced this?  Should I pull the distributor and try to rebuild it again or is that not the issue?  

 

Thanks for you help and remember, I'm a newbie!  

 

Geoff

Edited December 14, 2020 by GrahamPaige29
wrong code (see edit history)

[Rusty_OToole]

Wandering indicates worn distributor. Could also be idle set too high, meaning the advance is kicking in. Old engines idle very slow, like 400 rpm. Check the distributor for worn bearings, if you can move the rotor shaft from side to side it is worn.

[GrahamPaige29]

1 hour ago, Rusty_OToole said:

Wandering indicates worn distributor. Could also be idle set too high, meaning the advance is kicking in. Old engines idle very slow, like 400 rpm. Check the distributor for worn bearings, if you can move the rotor shaft from side to side it is worn.

Hey Rusty.  Thanks.  I think I had it idling too high.  The carb settings are still a little finicky but I'll try tomorrow to run her WAYY lower at idle and check again.  Also, I should have someone else rev her for me and see if the timing changes.  If not, am I safe in guessing the mechanical timing isn't working right?

 

Seems like I'm getting more than one timing light flash per cycle.  Any guess as to why???

[Oldtech]

I Agree. Usually caused by worn bushings in the distributor which allow the spark to occur at a different spot on the point cam.  I suppose the advance could be doing it but it would have to be totally pooched.

[edinmass]

Bad bushings are common on pre war cars..........just finished installing a set today.

[GrahamPaige29]

Thanks guys.  I'm going to examine the distributer today for wear.

[Bud Tierney]

Would worn timing chain/gear allow such fluctuation??

[dictator27]

43 minutes ago, Bud Tierney said:

Would worn timing chain/gear allow such fluctuation??

Yes.

[JimKB1MCV]

  One of the keys to troubleshooting of any kind, is  to fix or verify proper operation of the easiest/least expensive items that could cause the problems first before delving deeper.

  If your distributor has no excessive shaft wear, centrifugal advance in place and working and the points are gapped to specs, spring tension on the points in spec, then its time to look deeper.

  The distributor really should go to a shop to fully spin test it, look at advance curves and general performance.

  My money is on loose bushings.

  Good luck.

[PhilAndrews]

Are you using a stroboscopic timing light with an inductive pick-up that clips around a wire, as opposed to the older self-powered neon type?

I find mine is sensitive to noise from neighboring wires, though the coil I have fitted is rated at a higher output voltage than the original and it was causing the insulation to break down where the wires came together into the wire harness. 

That was enough to trigger the electronic strobe, but not enough to trigger the neon.

 

I ended up making a new set of wires that resolved the flashover problem, and a new set of plugs because some had been manhandled in the past by a previous owner and had cracked nose insulation- removing the plug and measuring the resistance across the body to the connector on top showed several in the 2-3000 ohm range which caused intermittent spark and rough running.

 

It also accentuated the flashover in the wire harness because the cracked plugs represented an easier path to ground, even via the insulation of the wire.

 

The rest of it does sound mechanical though, I'll agree.

 

Phil

Edited December 16, 2020 by PhilAndrews
Typo (see edit history)

[GrahamPaige29]

1 hour ago, PhilAndrews said:

Are you using a stroboscopic timing light with an inductive pick-up that clips around a wire, as opposed to the older self-powered neon type?

I find mine is sensitive to noise from neighboring wires, though the coil I have fitted is rated at a higher output voltage than the original and it was causing the insulation to break down where the wires came together into the wire harness. 

That was enough to trigger the electronic strobe, but not enough to trigger the neon.

 

I ended up making a new set of wires that resolved the flashover problem, and a new set of plugs because some had been manhandled in the past by a previous owner and had cracked nose insulation- removing the plug and measuring the resistance across the body to the connector on top showed several in the 2-3000 ohm range which caused intermittent spark and rough running.

 

It also accentuated the flashover in the wire harness because the cracked plugs represented an easier path to ground, even via the insulation of the wire.

 

The rest of it does sound mechanical though, I'll agree.

 

Phil

Hey Phil.  I'm using a brand new inductive pickup light.  It has to run on 12 volts but my old car is 6 so I had the main power coming from the battery off my Hyundai.  Seems no matter how carefully I try to clip on the inductor it picks up other wires.  Really irritating.  I took my spark plugs out today and cleaned them up, as there was a lot of carbon on them.  I've also got a new coil coming as the old one was pretty dicey.  I'm thinking of using better insulated cables too.  Or I could search online for one of the old neon lights haha.

[PhilAndrews]

The GP floating with regard to the Hyundai will generate errant signals in the timing light circuirty too, but not much you can do about that with the way they are made.

 

The older neon strobes work well but are very dim compared to their modern counterparts, keep that in mind.

 

Making sure the basics are good before hurling money at it is the way I like to begin, but that's me... Ignition systems are always great fun if you have a masochistic streak!

Sounds like you are getting on the right track with it though.

 

Phil

[rodneybeauchamp]

Geoff,

I bought myself a nice modern digital timing light with dwell and tachometer to replace my older Optilux because I could no longer get a replacement xenon globe (Bosch).

 

Found I had all sorts of issues on my 1938 Buick 6V trying to get it to function yet it worked perfectly on my 1963 Riviera with 12V.

 

Seems it did not like the solid copper core wires I was using on the ‘38, so ended up replacing the number one lead temporarily with a resistor style. I then got correct readings.

 

Might be the issue.

 

cheers

Rodney 😀😀😀😀😀😀😀😀

 

PS if I had read the instructions (web based) it did mention that issue, but who reads instructions 🤔🤔🤔🤔🤔