Timing difficulties

M

Mad Mac

Senior Member
I am definitely "electrically challenged", but am trying to change that. The motor in my 29RPU needs timing better, so I decided to use the Les Andrews method as shown in Jack Bahm's great video. So here's what happened:

Turn key off
Spark lever fully retarded (up)
Use timing pin and dimple to get TDC on No1 (rocking in 3rd gear)
Connect test-light to LHS coil terminal (LHS facing forward) and to ground
Test-light comes on, as Jack says it should.
Turn ignition key on and Jack says test-light should go off - but it stays on.
When opening and closing the points with a screwdriver - light stays on all the time. Opening and closing them has no affect.

Its frustrating when you follow the directions exactly and still get the wrong result. So what's happening here and what do I do next?
 
There's an open somewhere between the coil and points. Switches are one trouble spot.

A broken wire on the lower plate would be the next thing to check.

Popout cable not screwed in enough or a broken wire in it would be the third thing to check.
 
You might be on the wrong side of the coil... t would be the red wire that goes to the points..
Its usually the r/s of the coil
 

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Mitch//pa said:
You might be on the wrong side of the coil... t would be the red wire that goes to the points..
Its usually the r/s of the coil
Click to expand...

Thanks Mitch,
That's one of the puzzling things about Jack's video - he says the red wire is on the LHS (upstream) side of the coil, but on my truck it is on the RHS (downstream) side. However I guess it doesn't matter what colour it is, as long as it does the job. And beside, the motor ran anyway, although retarded.

Since my above posts, I have recently re-positioning the rotor as shown on Marco Tahtras' diagram and there is a noticeable improvement in power. But I would still like to use Jack Dahm's method to get it timed even better.

Just a thought: Maybe I am confusing driver's side with passenger's side (I am in the southern hemisphere:)) so I will have another look at Jack's video.
 
jack says drivers side meaning left side sitting looking forward. I did it like he says in the video and worked great.
 
Beauford said:
jack says drivers side meaning left side sitting looking forward. I did it like he says in the video and worked great.
Click to expand...

OK, here is a pic of my coil showing the red wire on the RHS instead of on the LHS. I guess that was a mistake I made years ago when I rewired the car. But does it really matter if the motor runs properly? Maybe it is a cause of my current inability to get Jack Bahm's result with the test light?
 

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I had the same problem with light staying on and I tightened coil and light should only come on turning the cam.
 
Could the light be staying on because the condenser has gone short circuit. Doubtful if it runs but easy to check.
 
I don't think "rocking in 3rd gear" is correct. You should always move forward to take the slop out of the system.

Charlie Stephens
Mad Mac said:
I am definitely "electrically challenged", but am trying to change that. The motor in my 29RPU needs timing better, so I decided to use the Les Andrews method as shown in Jack Bahm's great video. So here's what happened:

Turn key off
Spark lever fully retarded (up)
Use timing pin and dimple to get TDC on No1 (rocking in 3rd gear)
Connect test-light to LHS coil terminal (LHS facing forward) and to ground
Test-light comes on, as Jack says it should.
Turn ignition key on and Jack says test-light should go off - but it stays on.
When opening and closing the points with a screwdriver - light stays on all the time. Opening and closing them has no affect.

Its frustrating when you follow the directions exactly and still get the wrong result. So what's happening here and what do I do next?
Click to expand...
 
You can always use your crank handle for finding the dimple in the Timming gear the main point is the use of the light to know that timing is set correctly!!! Jack is a great mechanic thanks for making the video
 
Since you have a non stock coil, who knows which primary terminal is the positive one?
Many people have tossed their good original coils and installed aftermarket coils with a clamping screw. The screw can be loosened and then the coil turned half way around, so don't worry about which side is which when you use aftermarket parts.
Ford even changed sides of the coil at the end of 1929. Read about it in the SERVICE BULLETINS.
The coil puts out the same voltage wired either way, but the spark plugs fire with less voltage when the center electrode is negative.
Do a Google search for "COIL POLARITY" by the chicagolandmgclub.

If you're lucky enough to have the coil marked with + and- signs, then it's easy to know if you have the + going to the red wire, which leads to the points. For unmarked coils you just do a coil polarity check by using a pencil or analog meter.

If you set the points first to .020" gap, then position the rotor as Marco shows when the timing pin is in the cam dimple, you'll have perfect timing. You can pull the head and find absolute TDC, then install a degree wheel on the front pulley, and you won't be any better off than using Marco's method.

____________________________________________________________________
My car needs washed.-------- My car needs TO BE washed.

When people leave out "to" and "be", what do they do with all the extra time they just saved? :D
 
Tom Wesenberg said:
____________________________________________________________________
My car needs washed.-------- My car needs TO BE washed.

When people leave out "to" and "be", what do they do with all the extra time they just saved? :D
Click to expand...

Mine "needs restored"...and I'll use the extra time to work on it ;)
 
Tom Wesenberg said:
If you set the points first to .020" gap, then position the rotor as Marco shows when the timing pin is in the cam dimple, you'll have perfect timing.
:D
Click to expand...

Thanks Tom,
In the end that's exactly what I did, and now the motor seems to be timed correctly. The reason I wanted to use Jack's method was to try to achieve an even higher standard of accuracy, if that is possible.
Mac
 
Mad Mac said:
Thanks Tom,
In the end that's exactly what I did, and now the motor seems to be timed correctly. The reason I wanted to use Jack's method was to try to achieve an even higher standard of accuracy, if that is possible.
Mac
Click to expand...

No need to get so futzy fussy! As soon as the engine starts and you pull the spark (timing) lever down to your favorite position, you have changed the timing to an unknown degree!! You most likely have no idea what the timing is set at: Did you set the lever exactly half-way down? two-thirds? Did you count the clicks each time? For example, how many degrees did you advance the timing when you moved the lever 10 clicks? 13 clicks (or whatever)?
 
40 Deluxe said:
No need to get so futzy fussy! As soon as the engine starts and you pull the spark (timing) lever down to your favorite position, you have changed the timing to an unknown degree!! You most likely have no idea what the timing is set at: Did you set the lever exactly half-way down? two-thirds? Did you count the clicks each time? For example, how many degrees did you advance the timing when you moved the lever 10 clicks? 13 clicks (or whatever)?
Click to expand...

Also my feelings on timing a Model A. I think it is much more important to know how far to advance the timing with the lever and that comes with experience. Getting precious about getting it exactly right when the engine is stopped doesn't count for much when you're motoring happily down the road at 50.:D
Just don't set it to fire BTDC when timing it or it could kick back. Other then that, a few degrees here or there don't matter much. On most cars, the lever is rarely, if ever pulled pulled all the way down so there is plenty of advance available.
 
I have one of those coil polarity tester tools / lights. I like tools:)
Its comes in handy when performing drivability / wiring issues on A's that come into the shop.
A quick test lets me know quickly that the coil is wired correctly...
i look professional using it:cool:
 
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