Hi guys and thanks again for all your efforts!
Today I did a continuity check on the orange, purple, and black wires going from the ICM to the distributor. All three tested ok - no break in them. I'm still not sure about the old 4 pin harness connector from dist. to ICM. Those spade connectors should be making contact, but that is the connector that a lot of dielectric grease on the contacts themselves. right after installation I couldn't get any spark anywhere, not even at coil. this connector has soft rubber at both ends and a hard plastic body. Can it be taken apart with destroying it, or are replacement plugs available that will connect to the ICM?

Right after reconnecting the harness this PM, I tried number one plug again and got a tiny spark for a second or two and the other cylinders sounded like they were trying to fire. and then no spark or firing at all.

My battery is at 12.7V, not sure what I'm getting at the coil or from the coil, but the last time I checked the coil spark it was bright blue - no orange.

I can pickup a spark tester, but don't you still have to interpret the color of the spark? or does it give you more meaningful data?

I have been holding the plug myself against a good ground (alternator bracket for plug number one and the old a/c bracket for the coil wire) I'm using a remote starter but i Like the idea of having my wife hold the hot end! I'll let you know what she says!

Chuck M.

 

The distributor connector is the one piece that is not directly available from any sources (even Motorcraft)

Did you test the black wire from the distributor connector to ground as was outlined?
Did you check that the screw was tight to the little brass 'ear' inside the distributor at the rubber strain relief?

You have a bright blue spark from the coil, but "a tiny spark for a second or two... then no spark or firing at all" coming from the #1 plug wire.

1) Do you get a spark from the coil when the spark from the plug fails?

You have a new coil, cap and rotor.
Connect a test light to the coil input as Jim's Rebel outlined.
At least then you will know if there is a pulse ungrounding the coil.

A lot of this points to a bad ground.
The only source of ground for the module and coil is that little screw in the dizzy.

 

By distributor connector do you mean the 3 pin connector that ties the purple,orange(yellow in my case), and black wires to the ICM? There is a company (pico wiring) that makes connectors for the module end of that connnection and the 3 pin version looks like a good substitute for the distributor end.

I have tested the black (ground) wire coming from the distributor. Did so by running the meter from battery positive to the black connector at the distributor. result was the 12 volt battery reading. I believe this shows that the black wire in distributor is a good ground. If there is another way to test this let me know.

I did not recheck the coil spark at this time. will do it today.

Don't currently have a test light, will try to rig something up today.

I have two black ground wires going into the connector at the ICM module connection. Not sure where the other ground wire goes or if it could be a problem.

I'll check the screw in the dizzy today.

I'll also followup on Rebel Jims suggestions.

One other note - both my old cap and the new one fit a little loose on the distributor body. The little metal clips don't hold the cap down tightly. It won't pull off, but there definitely some play there. Could that cause this problem? I know the connector to the rotor is spring loaded so I think is still making good contact, but not positive about that.

 

quick update :

Bought spark tester - same results. Good blue spark at coil, no spark at plug. I am now using the same ground spot though so there is no question of different ground capacity.

Checked coil negative and got pulsing light. Just to be sure this is what you had in mind, I attached one probe of the test light to coil input pos and the other to coil neg. with ignition on got steady light and with engine cranking got the pulsing light. Let me know if this is wrong.

Looking for the ground screw in the dizzy. No screw visible, there is a black rubber cover over the three wires entering the dizzy. There is a plated eyelet (could be brass) coming from the covering but it is not attached to anything and there is no screw hole near it to attach to. I have not tried to pull the black cover off yet, didn't want to tear it. Do you know if that cover just pops off? hopefully there is a screw or some other positive ground attachment inside.

Thanks

 

Do not try and remove the black strain relief.
There should be an eyelet on each side of the black rubber.
You want a screw on the side away from the vacuum advance arm.

The rest of your tests seem good.
How old are your plug wires?

 

You are absolutely right! There is a second eyelet going to a screw on the left. My eyes sure aren't what they used to be, plus the eyelet I saw first is bright and shiny - the real ground eyelet is dark and dingy. It is however firmly attached to the base. I backed the screw out a couple of turns and then retightened. Earlier when I only saw the other eyelet, I checked for ground and got a very solid reading.

Coil voltage - with battery reading 12.5v
Coil in from connector cap reads 11.6v with ignition on.
Coil out from plug reads 12.5v. using the battery negative as ground.

Not sure about only 11.6v in - maybe I didn't have the clips on tight enough or is that maybe the source of the problem?

 

It doesn't sound like there is an issue with the coil "trigger". I don't think you will find a problem on the primary side (power, ground, control, etc.) of the coil since you are getting a spark from the coil when you crank the engine. I would focus on the secondary side.

Maybe you already addressed this (I don't recall the entire thread now) - but have you tried a new set of plug wires? If not, maybe you can borrow one wire from another vehicle just for testing.

My other thought is that the coil just isn't cutting it. You have a spark at the coil but you can't really tell how "much" (I know the spark is "blue" which is nice but how many volts/joules is that?). Could be that the coil is jumping the gap from secondary to ground while testing, but its not strong enough to make it through the cap and plug wires to your spark plug/tester.

Are you sure the inside of the distributor cap is clean and dry? Moisture and carbon tracking inside the cap can cause this kind of issue.

 

... New cap and rotor.
I've asked about the plug wires twice already.

Agreed that there is a secondary problem.
Whether plug wires, or coil to cap wire (more likely given all plugs are having a problem firing) is the question.

 

Spark wires were replaced by PO, but I don't know when. they don't look too bad, but trying a known good one from my F150 should be easy enough!

the coil installed now is only 8-9 months old but I will recheck resistance. Also, I still have the old coil and it was reading about the same as the new one, so I will swap it in to see if it helps.

The inside of the distributor is dry and clean.

I'll keep you guys posted. I really am open to any suggestions!

 

Is the center (coil) contact in the distributor contacting the rotor properly?

Is the center "button" in the dist cap spring loaded (like the HEI distributor) or is there a springy center tab on the rotor? I don't recall the factory setup now. Either way you could put a dab of dielectric grease on the center contact area of the rotor, re-install the cap and crank the engine, then remove the cap and inspect the rotor to be sure there is contact.

Did the new cap look exactly like the one you replaced? You mentioned (I think) that it fit a little loose. What replacement coil did you use - a "performance aftermarket" or a "OE direct replacement" from the local parts store?

I'm just grasping now.

 

Factory style cap has a spring loaded button.

But he had this issue before he bought a new cap and rotor to try and 'solve' the problem.

 

I've been tricked before by troubleshooting some issue, replacing a part (that should have fixed the issue) it only to still have a problem, then assuming it must be something else - and after countless more hours of troubleshooting and looking elsewhere, (and maybe replacing other parts) coming back to find the "new" replacement part I got was bad out of the box.
At a dealership or repair shop you usually have the luxury to have plenty of parts around to swap in"known good" parts to test theories, but the home mechanic has to spend money to test with parts.

I'm suspicious of the coil, and I'm not confident in the OP's mechanical skills and test equipment (no offense intended), so it is difficult to rely 100% on the test results stated. Not to mention the crappy so called parts clerks now days that will gladly give advise and sell you the wrong parts all day.

I'm rambling now.

 

Update: Engine is running fine now but haven't had a chance to test it under load. Probably tomorrow.

Main problem appears to have been the coil wire at the distributor end. When I was hooking it up to the new cap, I noticed it did not seem to snap on and came off very easily. I tried it on the old dist. cap and found same problem. Had not noticed it before and have pulled and replaced this wire several times over the past week. I used pliers to squeeze the metal contact and there is now spark to all wires.
2nd note - reinspected all the spark plug wires and found number six had a cut around half the outer covering. Also, the PO appears to have replaced number 5 wire as it has a different boot than the rest of the set. Not being sure of the age of these wires, I replaced all today with a borg warner set .

Thanks again to all who responded with excellent advice!!

 

Glad you got it figured out.

It's never a good sign when the wires don't click into place.

If you have the money, buy a good set of wires.
Not the cheapest and not some $$$ snake oil.