Could it be the timing?

drscott

drscott

Member
SO I decided to take the 30 A pickup out today for a test drive. Been having a little trouble grinding gears while shifting. Adjusted the clutch some, drained the ****** and put in new fluid. Happy to say, it shifted great. But on the way home it started missing real bad, bucking and jumping and quit right in the middle of road. It was not out of gas. made a road side adjustment on the points and was able to limp home which was only one mile away. It would run good with the spark fully up, but when I pull it down it died eveytime.

So I retimed it and again, it started right up. Pull the spark down and it dies. Now I did notice my coil wire that goes into distributor is very ragged and has the brass tip missing. But, I would not think it would run that good with the spark up if the coil wire is the problem.

Timed it again, same results. Quits when I pull spark lever down.

IM a shade tree mechanic at best. But i have had several A-s and timed them many times. But, maybe I am missing something.

Any suggestions would be greatly appreciated.
 
drscott, make sure the spark rod going to the distributor is not rubbing on anything, I've had this happen before.Watch the top of the engine with someone pushing the spark lever up and down. Sometimes it's a good idea to do this in the dark so you can se if anything is arcing. Frank
 
1. It is probably all happening inside the distributor.

2. Exposed un-insulated pigtail wire rubbing on the metal distributor body as the distributor upper plate is rotated.

3. Happens often with Model A's after years of use -- worn out wire insulation not a big deal -- under $3.00 for a new wire & on your way!
 
Happened to me this weekend. Pulled the top plate off and found the wire from the bottom plate to be a bit old and stiff. The nut that hold the wire to the "point stud" wasn't tight. When I advanced the spark it would move under the loose nut and ground out on the distributor body. H. L has right I do believe.
I took it to the shop and found a starter brush the had fine copper wire and is very flexible. I used that and made a new lead.
 
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Could be any of the above. If you are running modern points with the wireless lower plate, the connection is shorting against the distributor housing. You can mark where the rotor tip points with the back lash backed up on the distributor housing. If the engine is in time, all you will have to do is return it to the same spot, and you won't have to go through the process of re timing. You can remove the distributor cam and upper plate to check for shorts and save some time this way, that is as long as you don't forget and turn the engine.
 
It really seems its in the timing or point gap. I have re-time a couple of times now. I started the points gap at 20k. Runs fine with spark up, pull spark down and it quits. I set points at 16k or so and it ran both with spark up and down, but not real smooth.

Went to 21k on gap and it dies with spark down.

Love this thing, but can make you say shuckey darn ever so often. :-)
 
when you set the timing did you do it with the spark lever full up position.
just thought it might be worth mentioning
 
i do think you need to look under the plate at the wire also. if you put a spark tester inline to the coil wire then your able to see if it gets erratic or loses spark when advancing.
 
Have you checked the point gap with the spark advanced and retarded
to see if it stays the same?

Bob
 
1. In message #11, the word "checked":

A. Does this word "check" include verifying voltage at the ignition points with ignition switch "ON" while using an analog multi-meter, (with a needle), with the spark lever in possibly at least (3) positions of: All the way "UP", "Mid-way", & "Down".

B. Reason: With distributor top plate off, everything may "look" great; however, with the distributor top plate in position, & while rotating the top plate with the spark lever, it is impossible to "see" what is going on "under" the top plate -- could be the metal flag wire connector on the end of the wire grounding out, or who knows what.

C. A modern doctor would agree to use the multi-meter -- if you did not use a multi-meter, nothing like a true Model A Physician performing the check up.

Hope this helps.
 
If the terminal for the bottom plate, which is fastened to the bottom of the top plate, isn't bent at 90* it will hit some metal when the spark lever is moved. I've seen it happen and bending the terminal down to the side of the points nut fixed the problem.
 
I would take the distributor out and put it on the bench, put something on the points so they can't touch, TAPE. Take an ohm reading from the ignition tab inside to the upper plate, as you turn the upper plate the reading should not change (1.00), if it changes then you are grounding. With the wires loose, frayed or broken as mentioned above you may pick up a ground.

Most of the above ideas are on the money, but I did not see if you said you had orig. or Modern Points. With modern points the condenser screw in the top plate may be sticking trough the plate enough to touch the wire connecting tab on the lower plate, this screw passes right over this connector, if this is it you will feel a slight catch and again you will see a change in the ohm reading. If this is it, add a washer or simply grind this screw flush with the plate.
 
While I was writing, Tom made a good point, this wire end tab, if not bent out of the way can touch the spring, and if this nut is not tight the wire end can turn and ground like he is saying. Using the ohm meter will point these things out.
 
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