vacamatic system

[oldroyal]

Can a short in the vacamatic  wiring system cause no spark coming out of the distributor?   I have spark coming out of

the coil. The car cranks but will not turn over.

[Guest]

How can it crank but not turn over.  They are one and the same thing.  I don't know anything about "vacamatic wiring" but if you had spark before and not now it is more likely to be and "open" rather than a "short"

Is there spark going into the distributor???  Are the points opening and closing???  Is the distributor cap and/or rotor cracked???  What make of automobile?

We need more

Edited October 11, 2017 by Guest (see edit history)

[Frank DuVal]

I agree on terminology, cranking an engine and turning it over are the same thing. Just imagine using a hand crank, you are both cranking it and turning the crankshaft/pistons over and over. 

 

BTW, what is a Vacamatic system? The ashtray emptying system I have read about in the 50s?

 

Or do you own a '41 Chrysler?

 

What wires are going to the coil now?

[Spinneyhill]

Welcome to the Forum! I hope we can help you. Don't let the replies above put you off.

 

So the starter motor will crank the engine but it won't start?

 

I don't know how the Vacamatic system works, but I assume it is a development of the BW Overdrive gearbox. Theoretically, it is possible the coil is shorted because that is what happens for a fraction of a second on a kickdown gearchange. But unlikely. Anyway, you would not get a spark - the coil is shorted.

 

So you have a spark coming to the distributor (e.g. you short the coil HT lead to earth?). That means the Vacamatic system is not shorted.

 

But you have no spark at any spark plug?

 

The points must be working 'else you would not get a spark from the coil.

 

Is the centre contact in the distributor cap (it contacts the rotor contact) working? If the cap has aluminium contacts inside, check the centre contact (carbon): it can fall out.

 

Give us a bit more history of what you have and what you are trying to do. How these problems arise can be helpful too.

 

P.S. Some time ago I think I posted the pages from MoToR's manual about the Vacamatic, probably on the Chrysler General forum. Do a search for it.

 

P.P.S. Here ...

 

Edited October 11, 2017 by Spinneyhill
More information (see edit history)

[Rusty_OToole]

If the coil is making sparks the problem has to be in the distributor, the plug wires, or the spark plugs. Did you remember to put the rotor in? Do the plug wires check out good? If none of the plugs fire, check the coil wire first.

 

Are the plugs coated with gas and oil? Sometimes they get so gummed up they short out. The only thing that will restore them is sandblasting.

[oldroyal]

Sorry about the cranking and turning over.  The coil is making spark.  If I pull out one of the plug wires and hold it about a 1/4 of an inch

to the block there is no spark.   I've replaced the rotor ,cap , point s and capacitor.   This is a 1942 Royal. All this problems started after I replaced the

starter and solenoid. Before the starter wasnt engaging all the time. Now the starter is working fine.  

I want to thank you all for your help. I've had this car for twenty years and this is the first time I am having problem.  

I will be checking the plugs and wires ,coil wire and the other suggestions.  Thank you again

[61polara]

If you have grounded the coil large wire and have spark, but no spark to the plugs, it can only be the rotor, cap or the wires to the plugs.  If you see a spark at the points, your coil can still be bad.  I just went through this on a 42 Desoto at Hershey on Friday.

[Rusty_OToole]

One other thing comes to mind. Some old caps had a spring loaded carbon button in the middle, if it falls out the sparks can't get to the rotor. It is obvious if there is an empty hole in the middle of the cap on the inside.