very weak spark

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rod7515

rod7515

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I just bought a 66 273 dart. It wont start and I checked the spark. It has a very very weak spark when I remove the wire from the coil to a ground. I checked the points and they are breaking. Ive exchanged the coil with a good one from another vehicle. Could a condensor be the issue. I have currrent to the coil and the ballast is good. Where do I go now? I realize it could have jumped time but shouldnt I still have good spark?
Thanks
Rodney
 
A simple test lamp aint gonna work. You'll need a volts meter. There is a huge wire going to the starter so that and a good battery and ground would get a good turn over.
The cars electrical runs on a different hot wire. If you don't have a good 12 volts there, it wont start.
 
"Could a condensor be the issue?"

Yes it could be, if the condenser is bad all bets are off. It's simply a capacitor that temporarily holds a charge then discharges quickly when the points close. If it's leaky it won't hold a charge well and you'll get a weak spark. I used to always change the condenser with the points. Now I have electronic ignition which I would highly recommend.
 
You could try jumping a wire straight from the battery to the pos side of the coil temporarily and see if that helps.
If it does, then you know you have a low voltage problem in the wiring.

Good call on the condenser by the way.
 
Make sure your dwell is set correctly. Use a dwell meter. The coil may not be getting saturated(energized) sufficiently to give you a good spark.
 
Also, you CAN NOT evaluate spark when cranking the engine by jumpering the start relay.. This does not provide "full voltage" to the ignition.

You must do one of two things:

1--Test while cranking the engine using the key

2--Clip power directly to the coil + from the battery. However, this does not test the "full circuit" and if you leave this clipped on for long you can burn up the points if they "land" closed.

Don't forget could be a bad coil hi tension wire.
 
Stopped by NAPA during lunch today and got a condensor. Tonight I put it on and it started right up. Funny thing is that the guy I got it from said he just put new plugs, condensor, points, rotor, cap and wires on but he couldnt get it to fire. He even gave me the receipt for them. Of course it was parts from auto zone! Once it was running it had a dead miss. I pulled wires off of each plug and found 5 & 7 without spark. Checked resistance in wires and all looks good. Then went to start it up again and nothing. Now it has current to the main lug on the starter relay, and off the relay to the fuse block. Did not check it farther then that tonight. I do know that I have no power to the fuse block either. I dont know if it had power there originally or not. If i put a jumper from the positive of the battery to the ballast and jump across the relay it will start and run. I am guessing a bad starter relay.
I'm not planning on using this engine so I dont want to invest much in it. I'm going to go to a local garage that works on a lot of chryslers and see if they would have any old wires and distributor cap. Hoping maybe even a relay.
Any ideas? I feel like I bought a car bubba owned!
Thanks
Rodney
 
Relay has nothing to do with ignition voltage

I would not immediately blame the "first guy." "New parts" do not mean "functional."

So far as 5/7, it might be that wear in the distributor is "just right," or even a bent shaft, that those two don't open the points, or the opposite, the points never close on those two.. Wiggle the shaft, recheck point gap. What did you set dwell at?
 
5 and 7 often get swapped, they cross each other. Check the firing order. 18436572 clockwise. Drivers side front to rear cylinders 1 3 5 7, passenger side front to rear 2 4 6 8.
 
KitCarlson said:
5 and 7 often get swapped, they cross each other. Check the firing order. 18436572 clockwise. Drivers side front to rear cylinders 1 3 5 7, passenger side front to rear 2 4 6 8.
Click to expand...

Even if a person didn't know anything about firing orders, this would be easy to chk by just swapping them and see what it does. :D
 
I alway check spark using my wife. 12 inches between her feet and the ground is good spark. Anything less I try a stronger coil. MSD ( M akes S parks in D entures) She likes that.
 
Points are breaking on each lobe and shaft was not lose. I did check that last night. If the relay doesnt play a part it would have to Almost be a switch I would think. I do know I have no fuse block power. Will also need to check connections in main harness connections at firewall. The fuseable link was good as well going to that block. Thanks for help so far. Where can I get a wiring diagram. I would rather test then guess!
Rodney
 
You can download an entire free factory shop manual for '66 here:

http://www.mymopar.com/index.php?pid=31

direct linkey-doo

http://www.mymopar.com/downloads/servicemanuals/1966_Plymouth_Service_Manual.zip

Only deal with the above is that your viewer will show consecutive page numbers instead of Ma's "dash" numbering, so you have to play with page no's a bit

Sometimes easier, not always correct diagrams from same place

http://www.mymopar.com/index.php?pid=18

Direct link to diagrams

http://www.mymopar.com/downloads/1966/66DartA.jpg

http://www.mymopar.com/downloads/1966/66DartB.jpg
 
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