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bruce22 09-17-2012 08:44 PM

83 CJ7 Ignition Problems... Help!!
 
Hi All,
Losing $ and patience. 258 I6. No spark to plugs. Clicking sound at distributor when key is in "on" position. 12.3V DC to + terminal at Coil (Key in On position). Accel Super Coil. New distributor cap, rotor, distributor sensor, wires, plugs, Ignition Module, timing gears and chain.
Fuel to carb. Is there a switch relay somewhere? Or maybe a bad module?
Jeep ran OK for awhile, then only started when I let off on key. Now... nada. checked and cleaned grounds.
So what gives? Why the clicking sound at distributor? Its intermittent.
Motor does crank over.
Please help!!!

Thanks!

BagusJeep 09-17-2012 09:26 PM

1 Attachment(s)
Calm down, these Ford Duraspark systems and distributors are actually pretty simple devices.

Before you start anything toss the multimeter and get yourself a 12V test bulb with some long leads. Mine have 5m long leads and cost less than $5, best tool in the tool box for this sort of stuff.

Now, you have not explained when you changed all that stuff and when it last ran sweet. I see the timing gear and chain were changed, did it run OK after this?

The reason I state that is that sometimes we have problems and we change lots of gear and all we end up doing is introducing a further fault or just throw $$$$$$$s down the drain.

So you need to start with the basics and check the wiring and the voltages you get in Run and Start and whether you are getting a signal to the coil. This is where the test bulb comes in, easy to use and easy to read.

The simplest test is to start with the coil:

1. Disconnect the wires from the +ve and -ve side of the coil. Are the connections good, the wires not loose or worn?
2. Connect your lamp between the light green wire that went to the -ve side and the battery +ve. Swing the engine, is the bulb flashing on and off? If so the Duraspark module and senor are working. If not then you can look harder at these areas. Report back and we can tell you how to check it all through.
3. Connect your lamp to the red with tracer wire that went to the coil +ve and the other end to the battery -ve post. In Run the lamp should be dim (6-7V), in Start bright (battery voltage, about 12V).

If it passes those tests you are ready to look at the high tension side. If not then you have nailed your fault.

Take an old spark plug and the HT lead that went from the coil to the dizzie. Put the s[park plug in the end and rest on the manifold. Swing the engine. Have you got a strong snappy blue spark? If not then it could be the coil. Report back and we can look closer at the coil. If you have had 12V in Run you coudl have burnt it up but you need to test it before replacing it.

If you have a spark then then try #1 lead from teh dizzie. Are you getting a spark here?

If it passes all those tests then you have a functioning ignition. That only leaves the question of ignition timing. Take out #1 spark plug and turn the engine by hand until you can feel peak compression. In the dizzie is the rotor pointing at the lead that goes to #1? If you had the lamp connected to the coil -ve and batt +ve you should see the lamp go out at this point. You can then check on the timing marks that it is near 8 degrees BTDC.

The clicking sound from the dizzie is a worry. Take tehg cap off and check the shaft is not loose or have excessive play. You can rotate it a little but there should be no sideways motion. The clicking could be the star shaped reluctor hitting the pickup sensor you installed. It gets close but not touches. Check the black wire that is in the harness with the pickup wires is grounded on to the distributor as this grounds the whole ignition.

Report back what you have.

bruce22 09-18-2012 09:25 PM

Thanks for all the info!! Got a light.
The jeep had already stopped working before I switched the timing gears. I had about 8-9 degrees play and a retired mechanic told me that it could have skipped a tooth and start by replacing those.

Ok, here's my report:
1. Check. Connections good. Disconnected.
2. Bright at "on" position. Dimmed in "start" position. No flashing. replaced module, no difference.
3. Bright in "on" position and dim in start position.

So I get the opposite of what you said I should get. You said I "nailed my fault." Does that mean the coil? But why would I get opposite results/failures with the coil disconnected?

Placed plug in end of coil-distributor wire. Turned motor, no spark.

So what's the next step?
Again, I really appreciate your time and expertise with this!

BagusJeep 09-19-2012 01:16 AM

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Yep, you have narrowed it down to two faults, one which will stop you dead and one you may want to fix later:

1. Your Duraspark is not working, you have no signal.
2. You do not have a ballast resistor, you are feeding battery voltage to the coil in Run. If it is a ballasted coil it will eventually overheat. If the coil is not yet damaged then you can just buy a ballast resistor and wire it in as the diagram shows, or replace both. It can also effect the ignition module and melt it but less common. You may also have no connection between the coil +ve and the I tab on the solenoid, which is why you get a dim light in Start.


Ok, so now you have it narrowed down to the Duraspark you need to run a few tests to see what you have going to the box.

Starting with the 2 pin plug, take it out and we can examine what is being fed from the harness. There are two incoming wires, one light blue, one red with tracer. Get the test lamp, hook one end to the battery negative. In Run you should have a bright light only when you touch the red with tracer wire. In Start you should have it on both.

The red with tracer gives the basic power to the module, the light blue is mererly a signal you are trying to start, which then retards the ignition a bit to help.

If that passes then look at that 4 pin plug.

The black wire is the ground for the module. It is screwed down at the far end to the inside of the distributor, as you can see in pic below. With no ground you will get no operation. Hook your test lamp up to batt +ve and probe that black wire at the module plug. It should light up.

The green wire goes to the ignition coil -ve. You can test it for continuity with the test lamp, connected to the batt +ve and the green wire at the plug, by shorting the coil end of the green wire to the engine. Lamp lights, it is good to go.

That then leaves the sensor signal. It is a coil of fine wire that the magnetic star shaped reluctor (or trigger wheel) on the distributor shaft passes by.

Make sure it is properly mounted in the distributor and is not hitting the reluctor and is not too far away, see picture below. Connect a voltmeter across pins D2 and D3 in the 4 pin plug (violet and orange) and see if it fluctuates, in which case a signal is being generated. You can also test the resistance across the plug at the violet and orange wires. If the resistance is right then the coil is intact. It should be between 400 and 800 Ohms. If you do not get the right reading, try it at the connector next to the distributor.

One more thing I would check is whether there is a short at the plug. I had one and it stopped dead.

Somewhere in there you have a fault, try it and report back.

The good thing is that it does not sound like a valve timing or coil issue.

bruce22 09-19-2012 07:27 PM

I did everything and it works like you said it would.... I had 608 ohms at distributor. I had just replaced the distributor sensor 2 days ago.. still no start...

bruce22 09-19-2012 07:35 PM

when i had the distributor cap off, and key in run, heard intermittent sparks from coil.. bad coil? only thing i havent replaced?? how do i check if coil is good? I disconnected coil-distributor wire, held it about a half inch away from block, turned key to on position and it showed erratic sparks going to block. When cranked, no spark. I need to have this thing running by Thurs night!! Again, Thank you very much for your time and knowledge!!! Buying parts is the price of an education...

bruce22 09-20-2012 08:19 PM

replaced the Solenoid. It apparently had a crack in it as it fell apart in my hands. I'm guessing the intermittent spark was from the solenoid shorting out.
Now.... I only get 1 spark at the coil on startup. I checked my timing by hand setting it to 8 degrees btdc and making sure the distributor lined up perfectly with the sensor and 1 plug.
hmmm.. Any ideas? I'll look at the other guys posts and see if I can figure it out. uhg... I'm definetly cursed it seems... Had a nice backfire that brought the neighbors over and made my daughter cry. :) All good times....


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