No spark condition
 

Well I have the "A" cranking properly but I have no spark at the plugs. I did a search on the forum and began reading several posts regarding spark issues. I replaced the condensor only because I had a brand new one handy. I have spark at the coil wire. I did the test where I have the points in the open postion, the ignition key turned on, and "jump" the points to ensure I have a nice spark between the coil wire and ground. I cleaned the points and adjusted the gap but I don't have any spark at the plug. Any help is greatly appreciated.

Thanks
Mike

Re: No spark condition
 

If you have spark when you run the starter at the coil wire, but not at the plugs, make sure the cap and rotor are in good condition, there is a contact on the cap that must contact metal tab on the rotor. If that is good, then check the clearance between the rotor contact and the contacts that go to each plug.

Also make sure that the rotor is good, it has a tab that must fit down into the notch in the top of the dist. cam, or it will not turn.

Re: No spark condition
 

when you ck the spark make sure its a nice blue with some zap. a weak yellow won't make it to the elctrode on the plugs.
just recently had a weak spark and was able to hold the plug wire with my bare hand. didnt feel a thing:)

Re: No spark condition
 

Did you forget to install the rotor? I did that one time and saw a couple others also do it.

I've also seen rotors go bad where the spark travels right through to the shaft.

Re: No spark condition
 

The distributor cap and rotor were replaced a few years ago, they still look like they are in great shape. The rotor is down all they. I am pretty sure I did have the rotor installed when I checked for spark but I will double check these things though tomorrow to make sure I didn't miss them.

The spark I thought might be a little weak but it does appear to be blue in color. If I do have weak spark what should I be looking at?

Thanks
Mike

Re: No spark condition
 

A weak spark could be caused by a poor condenser or coil, but I'd try the condenser first. Changing the stock condenser is very quick and easy if you follow these steps exactly:
1. Lay the new condenser next to the distributor.
2. Remove the ground screw first, then walk to the drivers's side.
3. Remove the terminal screw and while keeping light pressure on the screw, slip the old condenser out and the new condenser in, and tighten the terminal screw.
4. Go to the passenger side and install the ground screw. Done and easy!

Re: No spark condition
 

I actually did change out the condensor today.

Thanks
Mike

Re: No spark condition
 

I had a 12 V system the other day that had a spark, weak looking to me, so we stuck a new coil on it. The spark looked the same to me, but she started up and ran. Before it would only run for a few seconds, then die and not start again until it rested for a while.

Re: No spark condition
 

Msaby,
IF the spark shorts through the rotor, it usually leaves a rainbow looking discoloration up inside the rotor hole where it fits on the shaft. Look at it outside in the bright sunlight. Or hold the coil wire close to the steel contact on top of the rotor & crank it over. A slight THIN spark might show, but if it is a good SHARP snap, then the rotor's gone KAPOOIE! With every tune up, REPLACE the rotor, & throw the old one AWAY! They're CHEAP. (Me Too!) Bill W.

Re: No spark condition
 

Is the rotor turning??
Paul in CT

Re: No spark condition
 

Yes the rotor is turning when I crank the engine.

Re: No spark condition
 

If you have spark at the coil wire but not after the cap then it can only be 2 things.
1] is the rotor is no good and is passing electricity through it and shorting to the dist shaft.

2] It is so far out of time that the rotor does not line up with the post to the plug.

Check the second first by using the coil wire. turn on ignition and rotate engine by hand until it sparks at the wire. then turn off ignition and put the cap and rotor on... Does the rotor line up the the post? If it does then it has to be the rotor.

Jerry

Re: No spark condition
 

Are you sure that you have the coil properly wired? Reverse the + and - and you'll still get a spark off of the coil wire, but it will be weak (often yellow instead of a loud snapping blue).

Re: No spark condition
 

When I get to the garage today I am going to check the rotor. I don't think the coil is wired incorrectly since the car had been running all these years but I will still check it to verify it.

Thanks
Mike

Re: No spark condition
 

Tom,

With regards to #3, how do you keep pressure on the screw if you remove it?

Marc

Re: No spark condition
 

the screw on the drivers side you hold pressure with the screwdriver and do not remove it.
just slide in the new cond and tighten back up

Re: No spark condition
 

Look at the height of the little flexible tab on the top of the rotor. Make sure it is tall enough to make contact with the underside button of the distributor cap.

Take an old distributor cap and cut two sides off of it so that you are left with a narrow strip that goes across the top of the distributor body and is held on by the 2 spring clips. It has the button in the middle and a place ot put the coil wire. Put your coil wire in that. Crank the engine in a dark area and look for sparks inside the distributor body. The A engine will actually run with this setup. Very helpful for diagnosis.

Re: No spark condition
 

Actually the coil has the same output with either polarity, but the spark plug fires easier if the hot center electrode is negative. Here's an excellent short read all about polarity:

http://www.chicagolandmgclub.com/tec...neral/574.html

Re: No spark condition
 

Jim makes a good point about checking the distributor when the cap is partially exposed. This will allow you to see whether or not the rotor is trying to spark to the contacts on the distributor body. It could be that the distributor cap to rotor gap is too much from wear.

The image shows what Jim was suggesting.

Re: No spark condition
 

Wow that's a great idea. I am going to the garage now and begin testing.

Thanks
Mike