Wits' end with no spark (really long post) '76 FJ40 (1 Viewer)

[Red Panda Roll]

I've searched for hours over the past week and have seen MANY threads about not having spark. I've yet to find one that answers my question, though.

3/1976 FJ40 with 2F engine.

It ran a week ago and then I started replacing some of the old, awful-looking wires a PO had installed. I DID NOT do this scientifically and change only one variable at a time testing the system after each change. (All together now: "Well, that was dumb!")

So this is where I am: The engine cranks (both from the key and from the remote starter I borrowed) but will not start.

I hear the fuel cut solenoid clicking when the key is turned on. There's fuel in the tank and it's in the window on the carburetor. Fuel is not the problem.

When holding the main coil wire (to the distributor) next to a ground there's no spark. Multi-meter measures 12-point-something volts, though. When cranking the engine with one spark plug removed and grounded to the head (wire still attached) there is only the weakest spark noticeable. I've got 12 volts at the contact points when open and almost none when closed.

Spark plugs have all been cleaned and re-gapped to 0.031 inches. There is a new ignition switch, distributor cap, rotor, points, plug wires, coil, and ballast bypass resistor. The engine ran fine after the ignition switch, cap, rotor, and plug wires and resistor were replaced two weeks ago. The battery was brand new a little over a month ago, though it is weak from all the unfruitful cranking. It currently is measuring 12.06 volts at the terminals.

This cruiser does not have a condenser installed (but it ran fine without one). I'm not sure if it's supposed to and truth be told, I don't know what a condenser does. (Besides condensing . . . something ... probably electrons or some such nonsense.)

The coil barely failed the resistance check in the manual so I got a new one from Pep Boys (the only place that had it in stock). I just now went out and tested them both and both of them failed. Dammit!

Old one (Nippon Denso) primary coil 0.7 ohms (pass). Secondary 9.06 k ohms (fail).
New one (BWD Select) primary coil 1.0 ohms (fail). Secondary 10.66 k ohms (pass). Can this really be the issue? If I'm going to spend another $30 on a coil I might was well get one with an internal resistor and then buy one of those Troll Hole electronic ignitions I've come across in my hours of dredging the forums.

I have checked, re-checked, and re-checked again, all the wires I've changed. They all have continuity, and go where the FSM diagram says they should. Every ground I've tested tested okay. I've cleaned any contact that was dirty with a wire brush or 1000 grit sandpaper.

If I crank the engine for more than 10 seconds or so there's a little bit of gray smoke that rises from the
starter end of the big red wire that attaches from the battery to the starter.

Last night I "hot wired" the coil to the distributor and still had the weakest of sparks. (It was coil (-) to wire that goes into the distributor's points, and black/yellow wire from ignition switch and black/yellow from starter to (+) on coil.)

I even drew my own wiring diagram of all the wires I recently changed to see if I would find an issue with the new wiring which I hadn't seen when staring at the 3-page FSM schematic.

The thing labeled "what is this?" is wired to the igniter. It appears to be made of ceramic and has "15H 12ΩK MICRON62" written on it.

I don't know if this diagram will help but this is what my ignition system currently looks like.

Thank you all in advance for your help! I KNOW I can get this running again with your brains. Fire away with your questions, etc.

 

[php74]

Is there an inline fuse somewhere in the mix. I toasted one once and it was still allowing a small amount of current through inside the melted mess. Good luck man, been there.

 

[Red Panda Roll]

Is there an inline fuse somewhere in the mix. I toasted one once and it was still allowing a small amount of current through inside the melted mess. Good luck man, been there.

That's a good thought. I've been over nearly every inch of the harness and haven't come across any to date but just in case I just looked again. When I first started I thought there was one but I think it's actually supposed to be a courtesy light.

 

[AdamKFarmer]

Is your grounding strap to the frame good and clean?

 

[Jerry D.]

You show a wire from the COIL + going to the STARTER, and not showing it connected to anything (except the starter somewhere). The positive of the COIL has to be connected to a B+ (a 12V wire somewhere) or you will not have any energy for the coil to store up for a spark. I believe the COIL + wire should go to the IG wire.
I'll look for a better schematic.

 

[DougAustinTx]

Yes, there has to be a wire from the ignition switch to the ceramic resistor at the coil. Also, you didn't respond to the question that Akingf5371 asked: is the strap that holds the coil and igniter properly grounded to the fender? If not, you will never get a spark.

 

[Red Panda Roll]

Is your grounding strap to the frame good and clean?

The only one I've come across is from the bottom mounting bolt on the starter to the right frame rail. I took it off this morning, scrubbed both ends (copper connectors) with a wire brush and reinstalled it after scrubbing both mount points (on the starter and frame as well).

 

[Red Panda Roll]

You show a wire from the COIL + going to the STARTER, and not showing it connected to anything (except the starter somewhere). The positive of the COIL has to be connected to a B+ (a 12V wire somewhere) or you will not have any energy for the coil to store up for a spark. I believe the COIL + wire should go to the IG wire.
I'll look for a better schematic.

I tried moving that wire to the coil (+) with no change in the cruisers condition.

 

[Red Panda Roll]

Yes, there has to be a wire from the ignition switch to the ceramic resistor at the coil. Also, you didn't respond to the question that Akingf5371 asked: is the strap that holds the coil and igniter properly grounded to the fender? If not, you will never get a spark.

The black/yellow wire from "IG" on the ignition switch goes to the ballast bypass resister, though I tried moving it to coil (+) per Jerry D's suggestion. Still no joy.

I also just realized didn't draw the red wire that connects the bypass resister to the (+) on the coil.

I also removed the whole shebang (coil, etc.) and scrubbed to bare metal the mount point, mount hardware and strap. There is a small (white/black) ground wire that attaches to it and I cleaned that up, too.

 

[FJ40Jim]

"what is this" is a ballast resistor for the ignitor itself.
The one you replaced is the ballast for the ignition coil.
Neither of them are known to fail.

A bad coil will have zero or infinite resistance.
Put the good Toyota coil back in place, there's nothing wrong with it and it did run the engine before. The untested Chicomm coil should be returned to Vatozone.

On the diagram, there should be a single wire connected to coil - from ignitor. IDK what "ballast bypass resistor" is.

 

[AdamKFarmer]

This might be a dumb question, but in none of your pictures do I see the negative post on the battery connected to the frame. Have you taken it off?

NVM, I see it off to the side, I assume you took it off to trouble shoot.

 

[AdamKFarmer]

Also, do you have the OEM wiring diagram? If you print that out I may be able to swing down to Aurora and lend a hand this weekend. I would suggest the manual and a multimeter.

 

[JAFO2014]

When you know what stuff does and what to expect, only then can you fix something.

CONDENSER - Is a capacitor. It is in the circuit to keep the points from burning up. It would be across the points. It catches the voltage spikes that occur when breaker points open and close. The ignitor acts as a capacitor. I have seen a bad condenser keep an engine from running. You can test without the condenser. Just should be there for normal operation. But when it comes to the ignitor, that is sort of a different animal and I think it needs to be in the circuit.

Coil - builds up a magnetic field that collapses when the points open. The collapsing field produces current. Current must go some place. It ALWAYS wants to go to the path of least resistance. If the system is working correctly, when the points open, the coil field collapses and the current path from the coil is through the coil wire, to the cap, jumps across the rotor to the correct terminal in the cap (engine in time), out the plug wire, jumps across the spark plug to the engine ground. The jump across the spark plug makes the spark to fire the gas. That is why you need the engine grounded good and the battery ground and engine ground are the same so the plug is the path to ground.

RESISTOR- Is there to reduce the voltage at the coil. You could do tests without the resistor. On my old 1973 Ford Bronco the resistor is not in circuit during start so full voltage to coil, but is in circuit during run so lesser voltage during run. I am not that up on the FJ40 circuit. I think old FJ40's had 6 volt coils and definitely need a resistor during RUN mode.

IF YOU SEE SMOKE- when there is smoke, you either have a bad connection that is arcing, or something getting too hot, or maybe dust burning off something. I saw smoke on my old CASE Backhoe starter and it was the brushes, and they were smoking due to my battery being way too low. So sometimes smoke can fool you as to what is wrong.

Check all your connections. Make sure the coil has voltage. The points in the system are normally the path to ground. When closed they are energizing the coil and then they open, causing the coil field to collapse. When all is correct you should be able to arc from coil wire that goes into the cap to ground. And also with all connected, have a plug out and you should see the spark plug arc if you have it held against a ground point (engine head) as you crank.

 

[Red Panda Roll]

"what is this" is a ballast resistor for the ignitor itself.
The one you replaced is the ballast for the ignition coil.
Neither of them are known to fail.

A bad coil will have zero or infinite resistance.
Put the good Toyota coil back in place, there's nothing wrong with it and it did run the engine before. The untested Chicomm coil should be returned to Vatozone.

On the diagram, there should be a single wire connected to coil - from ignitor. IDK what "ballast bypass resistor" is.

Thank you for explaining what "What is this?" is.

Original coil reinstalled. The only wire connected to coil (-) is a black wire from the igniter. The red wire from the ballast for the ignition coil is connected to coil (+) along with the black/yellow that goes to the starter. The red wire from the igniter is connected to the distributor.

 

[Red Panda Roll]

This might be a dumb question, but in none of your pictures do I see the negative post on the battery connected to the frame. Have you taken it off?

NVM, I see it off to the side, I assume you took it off to trouble shoot.

There are definitely no dumb questions at THIS point. I usually disconnect both (+) & (-) from the battery for fear of causing a fire/meltdown.

 

[Red Panda Roll]

Also, do you have the OEM wiring diagram? If you print that out I may be able to swing down to Aurora and lend a hand this weekend. I would suggest the manual and a multimeter.

I believe what I'm using now is an OEM diagram. What I have is from the 1976 Haynes Manual. I also have the 2001 Mitchell one but Mark (Coolerman) said that one's not very good. I downloaded them both from Coolerman's site. (Coolerman's Electrical Schematics and FSM File Retrieval)

I do have a multimeter and both printed out. I would be so grateful if you could help me figure this out if you've got time.

I'll send you a PM.

 

[Red Panda Roll]

When you know what stuff does and what to expect, only then can you fix something.

CONDENSER - Is a capacitor. It is in the circuit to keep the points from burning up. It would be across the points. It catches the voltage spikes that occur when breaker points open and close. The ignitor acts as a capacitor. I have seen a bad condenser keep an engine from running. You can test without the condenser. Just should be there for normal operation. But when it comes to the ignitor, that is sort of a different animal and I think it needs to be in the circuit.

Coil - builds up a magnetic field that collapses when the points open. The collapsing field produces current. Current must go some place. It ALWAYS wants to go to the path of least resistance. If the system is working correctly, when the points open, the coil field collapses and the current path from the coil is through the coil wire, to the cap, jumps across the rotor to the correct terminal in the cap (engine in time), out the plug wire, jumps across the spark plug to the engine ground. The jump across the spark plug makes the spark to fire the gas. That is why you need the engine grounded good and the battery ground and engine ground are the same so the plug is the path to ground.

RESISTOR- Is there to reduce the voltage at the coil. You could do tests without the resistor. On my old 1973 Ford Bronco the resistor is not in circuit during start so full voltage to coil, but is in circuit during run so lesser voltage during run. I am not that up on the FJ40 circuit. I think old FJ40's had 6 volt coils and definitely need a resistor during RUN mode.

IF YOU SEE SMOKE- when there is smoke, you either have a bad connection that is arcing, or something getting too hot, or maybe dust burning off something. I saw smoke on my old CASE Backhoe starter and it was the brushes, and they were smoking due to my battery being way too low. So sometimes smoke can fool you as to what is wrong.

Check all your connections. Make sure the coil has voltage. The points in the system are normally the path to ground. When closed they are energizing the coil and then they open, causing the coil field to collapse. When all is correct you should be able to arc from coil wire that goes into the cap to ground. And also with all connected, have a plug out and you should see the spark plug arc if you have it held against a ground point (engine head) as you crank.

That's all REALLY helpful! Thanks!

I'll take another look at my connections tomorrow and check for voltage at the coil, again.

 

[Red Panda Roll]

I checked all the connections and can't find anything that's not connected.

After reading a few MORE threads on similar problems I was thinking more and more it might be a ground issue. I added a temporary extra ground from the ignitor/coil mount foot to the battery (-) and another from the regulator mount to the radiator mount (on the frame). Still no spark.

I ran the test on the ignitor per the instructions from FJ40Jim (I think) hooking up battery negative to the mount foot, vice gripping a spark plug to the foot, and hooking to an unmounted distributor ... etc. There was no spark and no sound of spark but the ignitor took up smoking so I think it's probably bad.

Your thoughts?

 

[Pin_Head]

I'm confused, you get a spark but you say it is weak? A spark is a spark. Try pouring a tablespoon of gasoline in the carb and try it before you get too deep into the ignition.

 

[Red Panda Roll]

I'm confused, you get a spark but you say it is weak? A spark is a spark. Try pouring a tablespoon of gasoline in the carb and try it before you get too deep into the ignition.

At one point I had a VERY faint spark. Currently there is NO SPARK at all. Most of the time there's been no spark. I know what it should look like.

Carb is good. The fuel level is midway up the window.