New ICM did the trick. Even though the old ICM kept testing good.

New ignition coil, pickup coil, rotor, distributor cap, and spark plugs... Spark plug wires are 1.5 years old and in great condition. ICM tested good many times.

No spark. I get voltage to the ignition coil. Nothing further. The car has fuel and the battery is fully charged (brand spankin' new battery actually, replaced because old one was loosing charge).



Also, it ran perfectly until I parked it at home. Went to start it 2 hours later and no spark.
...

Anything helps.


And this is the wiring schematic.

 

replace your pick up coil. its inside the distributor. mark where the distributor is on the engine so you can drop it back in the correct spot. its realy not too bad to do.

 

Okay. And how exactly do I remove the pickup coil?

 

knock the dowl pin out of the dizzy gear and slide the shaft out of the housing and take the old pick up coil out and put the new one in, and reassemble distributor. been a little while since i did one so telling step by step directions isnt the easiest from a foggy memory

 

Nevermind I found the bold under a glob of grease under a loose wiring harness (damned previous owners). Now I just need to clean some of the grease off and get the bolt off.

Is the bolt the only thing I need to remove in order to remove the distributor, allowing me to get to the pickup coil?

 

yeah there is a one hold down bolt. make some kind of mark, or you will have to get #1 cylinder at TDC if you dont

 

Alright, I have to wait until tomorrow morning for the part to get here, so I'll update you then.

 

Eh, well I got the bolt out, and the distributor base is free to spin, but the shaft ain't pulling out. Did I miss something?

 

pull straight up realy hard. this has happend to me before. i know there is hardly any room in there, but you may be able to get a small pry bar, or screw driver to pry up on it

 

Ah, yes, got it. Why was I expecting it to come out easily when it's been in there for 30 years?

 

Never mind. I'm getting too reliant on posting questions instead of just looking it up.

 

im sure that will work

 

Okay now I'm just lost. Got everything back in, putting the distributor bolt back in... and it's not going in all the way, it stops half-way or so, and the distributor base spins freely. wtf?

It's too hot out to have these troubles. :/

 

the oil pump drive shaft needs lined up. you need a long flat blade screw driver to reach down in there and turn the shaft until it is aiming in the spot you marked it for the rotor. sometimes you can just drop in the dizzy slightly counter clockwise to your mark, and it will rotate slightly when getting completely seated and line right up

 

Alright, sounds simple enough. I'll get to it tomorrow when I have my hood taken off (which I should've done from the start), and when there is daylight again.


Thanks for all the advice too, you've been a huge help.

 

no problem. hopefully this is your spark issue. very unlikely you have wiring issues. if so there is a diagnostic tree for this

 

I'm pretty sure it's the issue. The old pickup coil is extremely corroded. The casing around the coil itself literally disintegrated when I got the coil out. The actual wire coil doesn't appear to be in bad shape, but the two leads going to it are very corroded and one of them appears to have a break from the coil.

In any case. I'm going to replace the ignition coil as well though because I'm pretty sure it's the original one that was put in 30 years ago, and doesn't appear to be in good shape. Would rather replace it now while it's still working than have it die out some time when I'm driving.

 

Got everything in, no spark. Replaced the ignition coil and spark plugs, no spark. no spark no spark no f'n spark.

And the wiring looks fine, but I suppose there could be a break in one of them...


Any other ideas before I start looking through all the wires and whatever else?

 

Check your grounds from the motor to the firewall. Make sure the coil has adequate grounds to the bracket (new bolts and straps). Check your security system!

 

The ground from the engine to the firewall is good. The ground from the ignition coil to the bracket doesn't look so great, it is grounded but the continuity light flickers a bit.

Also, I put a test light on all 4 of the ignition coil connectors, and they all lit up with the key turned on AND when the engine is turning over. The ground isn't supposed to be lighting up like that is it? That means it's always grounding out...


And, what do you mean by check my security system? I wasn't aware of any security system on or in the car?

 

Sorry i slipped on the security system, it would kill the injectors and crank, not the spark. If the coil grounds off through the straps then it would be normal for all 4 wires to show juice, but consult a wiring schematic to be sure.

 

You're correct the coil grounds off through the bracket it bolts onto. {source} I've never seen any straps that your talking about though. Is mine supposed to have some straps to ground it?

So at this point, I have replaced everything. New ignition coil, pickup coil, distributor cap and rotor, and spark plugs. The ICM is the only thing I haven't replaced, but I've had it tested many times and it always tests good. The ICM tests don't have false positives do they?

I've checked the grounds, they are fine.

I'm going to check the wires when I get a chance to work on it next... They look good, but I'll check each individual wire to make sure it has continuity from one end to the other.

Anything else that could possibly cause the problem?

 

The straps are the thin pieces of metal that bolt onto the outer edges of the coil pack. The bolts should run through them. They need to be clean and corrosion free for proper coil operation. The only things you haven't eliminated yet are the ICM and wiring issues. Wouldn't hurt to maybe tie a thick guage wire from the coil to a closer adequate ground for testing. If you don't have any luck by tomorrow evening I'll get the proper "no spark" testing flow chart off of all-data for you. Good Luck!

 

I was testing continuity and resistance between the wiring from the ignition coil (which tested good) when I came across this thing: https://i.imgur.com/WBzSE.jpg

It's bolted to the firewall near the top behind the distributor. It connects to the yellow black striped wire on the ignition coil...

Is it just a large resistor? It has 15.5k ohms of resistance. 8 volts when key is on, 6 volts when turning over.

 

Looks like a tach filter. Leave it off until the engine is running, then install it. That is just to be sure that it isn't interfering with the coil.

As for all four terminals on the coil having +12 volts, that is correct. The terminals of the two connectors on the coil feed straight across. The large red one is coil +12 volts, that goes across to the other connector and provides power for the ICM.

The other terminal is ground from the ICM to dwell the coil. It too goes across to the other connector to provide a feed for the tach.

The reason all four terminals has power as the primary coil winding goes between the power terminal and the ground terminal. Without the ICM grounding that terminal, you will measure +12 volts there.

The two-wire pigtail between the coil & ICM may be bad. The wire likes to break inside of the insulation, causing an open.

RBob.

 

Yeah I checked and each of the wires have good continuity, straight from the ignition coil to the icm.

 

How do I test the pickup coil? I know my old one was bad and needed replaced as soon as I got a look at it (falling apart, wire connecting to coil broken)...

But I'm not sure the new one I got is working. So how can I test it to make sure it is or isn't working?

 

Measure the resistance of it. Should be in the 900 to 1000 ohm range.

Lack of spark shouldn't be this tough. There are several ways to check stuff. Try a web search along with a TGO search on the trouble shooting chart.

Such as using a 9V battery to trigger the ICM. And ways to activate the coil via a jumper to ground.

Can even pull the distributor out, ground the body of it to the engine block, then key-on, engine-off and spin it by hand.

One thing to be careful of, is that even with no spark the ECM can be getting distributor reference pulses (DRPs) and fire the injectors. This will flood the engine. Disconnect the ICM 4-wire connector to prevent this.

RBob.

 

Nevermind the question. I am getting spark when I spin the distributor by hand. I also checked again and the ignition coil is not pulsing the test light when I crank the engine. AND the test light does pulse when I turn the dizzy by hand.

Put the dizzy back in carefully, and the car finally started.

I also just remembered that this is the first time I tried to start the car since went out and bought new bolts. Previously I had just used a wire brush on the old ignition coil straps and bolts and got them shiny, and it didn't start. I got new bolts for the hell of it, and put them in before I did the dizzy test. Put the old bolts back in, no start. Put the new ones in, start.

So, just cleaning rust and corrosion off of old bolts isn't enough to restore the conductivity of them.

 

I'm beginning to hate this car. No spark. It was running okay. I went to adjust the timing, but couldn't get it to run properly, It wouldn't run at all when set close to 10 degrees, and only ran smoothly around 30-40 degrees or so. I say smoothly, but it wasn't too smooth. Probably because of whatever reason it isn't getting spark anymore, again.


It's got to be a wire. I went back out, no changes were made whatsoever, and it started up again. After a few seconds however, it died, and got no spark at all. Can it be anything other than a wire? Bad ICM? Bad Ignition Coil (even though it's brand spankin' new)?

 

Since it seems you have an external coil, check the wires at the connectors on the ends of the wire running between the coil and the dizzy... I had the pink wire break on me at the dizzy end of the wire (well, it was almost broken, but it only had like 1 strand to hold itself together). I know yours is an earlier system, but the same holds true. If you can find one, maybe try getting a replacement wire and see if that helps.

 

Did you disconnect the EST wire before adjusting timing? Just Curious. Also did you use dielectric grease when installing the new ICM?

 

I don't even know what your referring to by saying 'EST'.

Also, I never got a new ICM, but I did use dielectric grease when reinstalling the one I have now.

 

Okay. The ICM was testing good, but I replaced it anyways. Problem solved. Runs perfectly.

I appreciate all the help.