Ignition retard-advance question

B

BlueSunoco

Well-known member
On a newly rebuilt distributor with original type points, etc. that I bought from one of the leading vendors, no matter how I try to zero in the timing (and I've done it about 8-9 times using Marco's method), it won't start with the spark fulled advanced you have to pull it down two clicks and then she pops right off. Runs good too no lack of power.

I am using the same dist. body I have had the last several years. I measured the opening for the spark lever connection w/ the upper plate on the dist. body and it is the same as several others I have, don't recall off hand what it is/was this was Saturday the last time I had a chance to monkey with the car. Never had this on a Model A Ford before and I'm stumped. Almost has to be w/ the dissy as that is the only thing that has changed in this formula. I've tried advancing the timing a bit no go.

Driving me bonkers it can't be right. Any hints are appreciated thank you. The upper plate must be a repop as it has no 'SP' for Standard Parts markings?? I checked the pigtail wire also thought maybe it was shorting out w/ lever fully retarded, it's OK.

Maybe the only thing 'fully retarded' is me, the operator!
 
If advancing the timing made no difference then the movement of the spark lever down slightly must be moving something in the distributor which is shorting.
 
I think you mean fully retarded. Full up on the lever. Full down is fully advanced. Always start with ign. Restarted. A notch or two down is about right. Don't worry!

Brian W.
 
Do you have spark with it fully retarded?? If not maybe the wire or
flag on the lower plate is shorting out.

Bob
 
If it starts when you pull the timing down two notches, what happens when the engine is running and you put the advance lever all the way up?
 
Tom's quick thought if I read him right is does it kill the engine or not...... thinking there may be a short in the fully "Retarded" position. I would suggest getting the multi meter out and check for voltage with the points open and the spark lever fully retarded. Put a piece of paper between the points if you need to and while pulling down the lever see if your voltage changes. Use the volt/ohm function on the meter to check for short/open.

It may be that the cam needs to come off and upper plate swiveled out to check and see what's going on. It could be that the distributor contact from the ignition cable is screwed in so far that the lower plate pushed into the casting and shorted as well.. although that is usually a constant.

Let us know what you find.
Larry Shepard
 
Yes it won't start with the spark lever all the way up, only when the lever is pulled down two notches. Then it pops right off and with the lever advanced runs like a top.

Duh I never thought about retarding the spark fully while the engine is running, sometimes you miss the obvious.

I have to go to a funeral today, one of the last of our WWII vets died, military services at the cemetery, so will be ******* most of the day. Will look into this with some of your suggestions and report back thanks much.
 
"Yes it won't start with the spark lever all the way up" Pull #1 spark plug and see if you get a spark with lever all the way up turning over with crank. If not then some electrical problem is indicated.

I would check timing as follows:

Make a mark on crank pulley and block at TDC as verified by piston location thru #1 spark plug hole and thumb over open #1 spark plug hole feeling pressure on compression stroke. Retard spark fully. With ignition turned on, turn over engine by crank with the #1 spark plug out(helps to have all plugs out). Note if it sparks at TDC. If not adjust advance to spark at TDC.

I haven't seen this check of manual spark setting posted here before. It is the only way that proves to me that timing is set correctly. Or use timing light with the home made marks. I've never been able to set timing accurately using any manual method. This check takes just a few minutes and you can then eliminate timing as the cause of any problem.
 
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Found the problem.

Went out to garage, started car with spark lever down two notches when I pushed it up to full retard motor immediately died. (Thanks Tom don't know why I didn't do that before;))

Took dist body and cap off, left the ignition key 'on' with spark lever all the way up then opened and closed the points. Saw a spark under the upper plate not at the points.

Took the upper plate off and found two things.

1.) Flag terminal to point assy. was bent down at about a 60 degree angle and

2.) somebody replaced the two machine screws to hold down the lower plate with rounded head machine screws and a lock washer. It was riding high. I took an original dissy apart and the lower plate used FLAT headed machine screws not rounded and no washer. The terminal was hitting that screw when the spark lever was all the way up.

So, the points were shorting to ground with the spark lever all the way 'up'. I gently bent the terminal more 'flat' and replaced the screw under the point assy. for the lower plate, with an original flat headed machine screw so that it wouldn't 'hit'.

Re-timed the car, and voila she pops right off with the spark lever all the way up, not two notches down, and purrs like a Model A should.

Thanks for all the advice!! I guess even w/ a good rebuilt from the major suppliers, you should pop off the upper plate and look at how they put it together. The 'fiber' washer they used under the points is a thin piece of white plastic basically, not the brownish-orange thicker washer on my original. Will work OK for now but will keep an eye on it!
 
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Here is a picture Marco posted showing how the flag should be bent.

Bob
 

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Bob C said:
Here is a picture Marco posted showing how the flag should be bent.

Bob
Click to expand...
Yes it was nowhere near that. The flag on this wire lead was bent down so that it was touching the rounded machine screw when you pushed the spark lever up. When you pulled the lever down then it cleared the screw, so it wasn't shorting out!

That looks like a 1931 distributor body with the cast 'bridge' above the clamping arms.
 
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