No Spark 1973 Cj5

Howdy,

I bought 73 CJ5 from a friend that has been sitting out in the woods for a few years. So far the list of issues are the obvious rust spots, bad gas, completely frozen rear drums, a desire for seats that are not coated in green moss and--the one I'm focused on right now--no spark. Engine is a 304 5 liter v8. I started with the most obvious:

Donor battery is from my diesel tractor, which can also run the equipment in an ambulance, I've been told. Point being the engine turns over with wattage to spare.

replaced carbon fouled plugs
replaced the wires--the new ones do not currently require any electrical tape

The old ignition coil wasn't getting high volt through but was getting low volt through. Replaced. problem persists.

replaced the confessor in the distributor and checked the points were .016 with a feeler I bought and ground down to fit in there. FYI-the cap looked good. Looked new inside to be precise.

After the last we buttoned her up and I forget to check spark again; went and sprayed some starter fluid into the carb while my helper cranked it. I was told when she barked at me that we coughed a good black billowy torrent of smoke for all of 0.5 seconds. So I'm thinking "Okay, problem solved. Move on to fuel." Today I cleaned out the tank as best I can without pulling it and ran new non-ethanol gas into the system. No cough, nothing. Went through fuel front to back and I have a semi-clear filter in the engine compartment so I can physically see the gas pumping into the engine from there.

Before taking the carb off, I decided to check for spark again. No spark on driver side. No spark on passenger side. Tested the tool with a 4 cylinder and got good flicker (so it's not the tool). My helper isn't here so I can't get back into it like I did yesterday and it's getting dark over here.

She fired yesterday. Twice, I think. Got enough compression to blow some smoke even. But today she just decided to roll over in bed and tell me she has a headache. I'm run smack dab out of ideas and smacking her on the behind only hurt my hand. Any suggestions would be appreciated. A full replacement of the distributor is not cheap for this 304...

Thanks in advance. Talk at you later.

 

Hi Scooter. Welcome from Boston. Sorry to start off negative, but you are in the wrong forum. A '73 is an intermediate Jeep, not an early.

Condenser?

You should have spark without cranking the engine. If you lift and then ground the coil wire to the distributor, it should spark. Does it spark? Ignition wires are a commonly neglected part of the ignition pathway.

A '73 has a Delco points distributor, and it's high quality and a fairly simple system. The points open and close to trigger the coil. You could try hot-wiring the coil to the battery, bypassing the ballast wire and ignition switch. Put a wire directly from the battery to the coil. Cranking is much more demanding on the battery than ignition, so if it cranks, you can rule out the battery. NB you'll need to remove the hot wire to kill the engine, if it starts.

 

The coil should only get full voltage input during cranking. Otherwise it should get about 9v if I recall correctly. There is a resistor to drop the voltage during normal key-on running.
304 V8 Coil / Resistor


I would try Tim's hotwire idea first. It also sounds like the distributor could be way out of timing. It would set the engine to TDC on cylinder 1, and then check the distributor position. I would also take the cap off, and crank the engine to make sure the Distributor is spinning

 

I thought maybe the OP was referring to the spark voltage; maybe not. It may be academic, but I would say that the ballast resistor is more about current limiting than voltage dropping.

Anyway, if it's been sitting in the woods for a while, there's no guarantee that it ran when parked. Setting the timing is a good idea - you should be able to find #1 TDC by rotating the crankshaft with the big nut on the crank pulley until the distributor rotor points to the #1 wire. Then you can static time a points ignition quite easily with a test light (a couple of clips, some wire and a 12V bulb). The VW guys static time their engines a lot, and there are several YouTube videos that show you how. It's a VW, but the components work the same way. If it's not in time, that should get you plenty close enough to run.

It's also possible that previously the distributor was removed and not put back correctly. To check that it's correct, you'll need to find #1 TDC. If you can crank the engine, take the #1 plug out and with the key off, use a remote starter switch or have your helper crank the engine and listen to the air rushing out of the #1 spark plug hole. Look at the crank pulley, timing marks and listen to the #1 hole. Air rushing out is the compression stroke. The exhaust stroke will be quieter. Stop cranking on the compression stroke, line up the timing marks, and check the rotor location. Should be pointing at the #1 wire. If not, the distributor rotation is messed up. If you find this, the easiest thing will be to re-order the plug wires in the proper firing order, starting with whatever location the rotor is pointing to. Then static time, and if it hasn't jumped time at the timing chain, it should start and run. Fuel plus spark equals ignition.

 

Does it have a resistor on the firewall? My 67 did and it broke. My 75 lost the ignition module twice..