No Start Help 1982 FJ45 (1 Viewer)

[bdsmitty88]

If you measure the resistance between the dizzy output post and ground, i guess you'll have a few ohms. You beeped continuity, but this doesn't mean it's a dead short - it could be a few ohms, and consistent with another load on the same line through the coil.

Secondly measure the resistance between the dizzy ground plate and battery negative - you shouldn't have a 1v drop there.

Thirdly, try removing the engine fuse and see if that helps.

Finally have you tried running it without the condenser fitted?

The mechanical speedo cable can easily short against the starter, but I don't know about the later one.

100A fuse?? That sounds a bit pointless unless you're running 1kw of stereo through your key switch which would be a bit silly.

Hey. I'm a bit puzzled now by the coils. Can you "kill" a coil and, if so, how quickly? Like, something in the ignition wiring going to the coil was incorrect. I purchased a cheap 12V, internally resisted coil from amazon to just rule out whether both coils I had were fouled from long term attempts at starting.

I connected the cheap coil, which tested in spec for resistance between both primary and secondary, and no start from the engine. The coil was getting correct voltage, showing 12v between the coil (-) terminal and battery (+) when battery off and slightly less than 12V between coil (+) and engine ground when ignition on. The engine just wouldn't ignite. I only tried for about 5 seconds.

Decided to disconnect the coil and hook it up direct to the battery and try the touch and go test, outlined here.
Testing the ignition coil - https://forum.ih8mud.com/threads/testing-the-ignition-coil.196883/

Bought a cheap spark strength tester off amazon and connected it with a high tension lead to the coil secondary. Did the touch and go test and could barely get it to arc the gap, even with the gap set to nearly zero. Just to confirm the part, we tried it connected to the modern ignition coil on my friend's car and it arced as expected showing 35KV...which is what we would expect. I also tried doing the direct to battery test with my 4runner battery just to rule out battery.
Amazon product ASIN B06X9RC3PF
So, is it possible that my truck wiring is making a coil go bad with just 1 5-10s crank attempt?

 

[Aussie Alaskan]

Hey. I'm a bit puzzled now by the coils. Can you "kill" a coil and, if so, how quickly? Like, something in the ignition wiring going to the coil was incorrect. I purchased a cheap 12V, internally resisted coil from amazon to just rule out whether both coils I had were fouled from long term attempts at starting.

I connected the cheap coil, which tested in spec for resistance between both primary and secondary, and no start from the engine. The coil was getting correct voltage, showing 12v between the coil (-) terminal and battery (+) when battery off and slightly less than 12V between coil (+) and engine ground when ignition on. The engine just wouldn't ignite. I only tried for about 5 seconds.

Decided to disconnect the coil and hook it up direct to the battery and try the touch and go test, outlined here.
Testing the ignition coil - https://forum.ih8mud.com/threads/testing-the-ignition-coil.196883/

Bought a cheap spark strength tester off amazon and connected it with a high tension lead to the coil secondary. Did the touch and go test and could barely get it to arc the gap, even with the gap set to nearly zero. Just to confirm the part, we tried it connected to the modern ignition coil on my friend's car and it arced as expected showing 35KV...which is what we would expect. I also tried doing the direct to battery test with my 4runner battery just to rule out battery.
Amazon product ASIN B06X9RC3PF
So, is it possible that my truck wiring is making a coil go bad with just 1 5-10s crank attempt?

After reading the entire post. I'm having similar (but different) starting problems to yourself and I just want to point out that for the tooling and test equipment you've bought you could have bought a DUI dissy and probably been good. It would consolidate quite a few of the components you are currently testing. Just a thought for you moving forward. I'm definitely considering it currently.

Good luck! My issue is that my rig starts fine when cold, but after warming it up it cranks all day, but refuses to start for an hr.

 

[45Dougal]

You fixed the dead short at the post. A continual current caused by that through the coil could have killed it (depending on its resistance)

 

[bdsmitty88]

After reading the entire post. I'm having similar (but different) starting problems to yourself and I just want to point out that for the tooling and test equipment you've bought you could have bought a DUI dissy and probably been good. It would consolidate quite a few of the components you are currently testing. Just a thought for you moving forward. I'm definitely considering it currently.

Good luck! My issue is that my rig starts fine when cold, but after warming it up it cranks all day, but refuses to start for an hr.

Check to make sure your choke throttle body isn't stuck closed. While not certain, I suspect this was the reasoning for my truck always starting worse when hot. I think the electrical problems showing up at a similar time are merely a coincidence, or different problems compounding one another.

 

[bdsmitty88]

You fixed the dead short at the post. A continual current caused by that through the coil could have killed it (depending on its resistance)

I did a bunch of wire tracing last night. I was thrown off by the connection between the thick black and yellow wire and the thin black and yellow wire being connected via fuse at the fuse panel. My improper ground is for sure on this thin black and yellow wire that runs from the fuse panel (engine fuse) to the regulator. The grounding is occurring somewhere on the inside of the vehicle...just need to do more tracing to find out where.

My question is...how would this not be blowing the engine fuse?

 

[jembourbe]

. . .

My question is...how would this not be blowing the engine fuse?

. . . because someone wired around it?

otoh, if that's true why did it run "OK" until it didn't? Keep tracing!

 

[bdsmitty88]

. . . because someone wired around it?

otoh, if that's true why did it run "OK" until it didn't? Keep tracing!

yeahhhhh....that's why i'm scratching my head. Idk how this electrical problem didn't affect me for so long.

If someone "wired around it", I still don't see how this wasn't an issue and blowing the fuse. That wire shows continuity with ground all the way from the fuse panel to the regulator...so it isn't like they crossed the wires, then uncrossed them further down the line or something. Could it be not blowing a fuse because the thick, main, black and yellow wire and ignition coil are absorbing this energy?

 

[45Dougal]

I did a bunch of wire tracing last night. I was thrown off by the connection between the thick black and yellow wire and the thin black and yellow wire being connected via fuse at the fuse panel. My improper ground is for sure on this thin black and yellow wire that runs from the fuse panel (engine fuse) to the regulator. The grounding is occurring somewhere on the inside of the vehicle...just need to do more tracing to find out where.

My question is...how would this not be blowing the engine fuse?

Probably because the resistance to ground is greater than 0.8 ohms that would be needed to exceed the fuse current limit.

Test the resistance and I think you'll find that this is a red herring.

Tried Unplugging the regulator?

 

[bdsmitty88]

Probably because the resistance to ground is greater than 0.8 ohms that would be needed to exceed the fuse current limit.

Test the resistance and I think you'll find that this is a red herring.

Tried Unplugging the regulator?

test the resistance across the fuse?

The regulator is currently unplugged, just for my continuity testing. Are you suggesting unplugging the regulator while trying to start the vehicle?

 

[bdsmitty88]

Are we sure that the small black and yellow "ignition fuse" wire shouldn't be reading continuity with ground? Like, are we sure that wire isn't meant to be a ground? It just runs from the fuse box to the regulator.

I've checked everything, tried unplugging every connector, etc. and it always reads continuity with a ground wire. No matter where I trace the wire, I can't find anywhere that it is wired into something it shouldn't be. It's easy to see that it isn't anything on the engine side. I disconnected one of the main firewall pass through connectors and the black/yellow wire doesn't read continuity with ground on the engine side of the wiring. This is the only connector that the black/yellow passes through the firewall. It reads continuous with ground on the internal side of that harness connector.

 

[45Dougal]

Probably because the resistance to ground is greater than 0.8 ohms that would be needed to exceed the fuse current limit.

Test the resistance and I think you'll find that this is a red herring.

Are we sure that the small black and yellow "ignition fuse" wire shouldn't be reading continuity with ground? Like, are we sure that wire isn't meant to be a ground? It just runs from the fuse box to the regulator.

I've checked everything, tried unplugging every connector, etc. and it always reads continuity with a ground wire. No matter where I trace the wire, I can't find anywhere that it is wired into something it shouldn't be. It's easy to see that it isn't anything on the engine side. I disconnected one of the main firewall pass through connectors and the black/yellow wire doesn't read continuity with ground on the engine side of the wiring. This is the only connector that the black/yellow passes through the firewall. It reads continuous with ground on the internal side of that harness connector.

As stated; I think this is a red herring.

According to my wiring diagram, the engine fuse should drive a green-red wire to the regulator.
The white- black wire is ground at the regulator - often these are dirty and look yellow-black.
Maybe grab a photo of the connections on your fuse box and regulator?

What do you mean by "it always reads continuity with a ground wire"?

Does this mean setting your multimeter to "continuity" setting and testing between the wire and ground?

Just because the meter beeps, does not mean the two wires are connected together. It usually beeps if the resistance is below a couple of ohms which may be completely normal depending on what else is connected.

Test the resistance between your distributor output post and ground and I think you'll find it is actually high enough that this is irrelevant.

 

[bdsmitty88]

Ok...I found my wiring source of confusion. I didn't even think of solenoids, then I thought about the starter wire...then it hit me. "where is the fuel cutoff solenoid getting power from?" Yep, the black and yellow ignition wire. It passes through the firewall from right behind the cluster. Didn't see it and didn't even think about it.

So...it seems as though i have been chasing something that doesn't exist and the actual wiring, itself, in my truck is fine. At least it forced me to do a good deep dive into the harness and figure out what all connections should be cleaned up and replaced. Aside from a few lazy connections and terminations, the wiring is in pretty good order.

Also, I figured out why the ignition coils were being so finicky with the bench test and not showing a strong spark on the spark strength tester. This test really needs a condenser wired in parallel, especially if you are just making the contact/break by quickly rubbing two wires together. The condenser prevents a lot of this energy from being lost as arc at the contact points, and I'm guessing it isn't fully charging or discharging the magnetic field due to inconsistency - causing either weak spark or excessive heat buildup.

I think I'm close...

 

[45Dougal]

Ok...I found my wiring source of confusion. I didn't even think of solenoids, then I thought about the starter wire...then it hit me. "where is the fuel cutoff solenoid getting power from?" Yep, the black and yellow ignition wire. It passes through the firewall from right behind the cluster. Didn't see it and didn't even think about it.

So...it seems as though i have been chasing something that doesn't exist and the actual wiring, itself, in my truck is fine. At least it forced me to do a good deep dive into the harness and figure out what all connections should be cleaned up and replaced. Aside from a few lazy connections and terminations, the wiring is in pretty good order.

Also, I figured out why the ignition coils were being so finicky with the bench test and not showing a strong spark on the spark strength tester. This test really needs a condenser wired in parallel, especially if you are just making the contact/break by quickly rubbing two wires together. The condenser prevents a lot of this energy from being lost as arc at the contact points, and I'm guessing it isn't fully charging or discharging the magnetic field due to inconsistency - causing either weak spark or excessive heat buildup.

I think I'm close...

Ahh there you go, boom.

So how is your condenser looking? Maybe worth switching it out for a couple of bucks.
The connections looked a bit tricky as I remember - maybe relocate it.

As I said before, you probably have a few things contributing a weak signal voltage, I'd try to find and fix a few of them if possible.

 

[jembourbe]

I trust you have already, but just in case you haven't looked here: FJ40 Wiring Diagrams - https://forum.ih8mud.com/threads/fj40-wiring-diagrams.571376/

 

[bdsmitty88]

I trust you have already, but just in case you haven't looked here: FJ40 Wiring Diagrams - https://forum.ih8mud.com/threads/fj40-wiring-diagrams.571376/

I snagged a few wiring diagrams from @Coolerman 's site and have pieced together something that pretty accurately matches my truck.

 

[bdsmitty88]

Ahh there you go, boom.

So how is your condenser looking? Maybe worth switching it out for a couple of bucks.
The connections looked a bit tricky as I remember - maybe relocate it.

As I said before, you probably have a few things contributing a weak signal voltage, I'd try to find and fix a few of them if possible.

The condenser has been replaced and bench tests in spec...as did the old one.

 

[bdsmitty88]

Any of you have experience removing the entire distributor assembly and then putting it back? I'm thinking of removing it, marking the relative orientation of it when I do, then bench testing it with a coil and plug hooked up. I saw a video where a guy connected a drill to the shaft to spin it close to idle speed.

The primary and secondary windings of the current coil, and even the previous one that I thought I fried somehow, both bench test in good order now that I know to perform the test with a capacitor in parallel. They both arced approximately 25KV when connected directly to the battery (12.3V). With the coil connected to the ignition wire and ignition on, I get about 11.4-11.8V between the primary wire terminals and ground. So, ignition voltage seems good.

When I tried the spark strength test with the coil all connected properly to the vehicle (ignition wire to coil + and coil - to distributor), I don't get any gap spark from the secondary when cranking the engine. In theory, this test should be 100% the same as the bench test. The only difference is that the points are now acting as the switch, whereas with the bench test the switch is me doing a touch and go with a wire from coil (-) to a wire connected to ground. I tried to generate spark with the condenser (the one that works for the bench test) connected internally in the distributor, as was stock, and connected externally as was done in the bench test. Ignoring anything else in the ignition circuit that could be behaving incorrectly, these circuits are the same. THE ONLY difference I can think of is that in the bench test the switch starts open and on the vehicle (assuming the distributor post cam is contacting the rubbing block with a flat side), the switch starts closed.

I'm nearly 100% certain that the points are connected properly, to a non grounded distributor post, so that the ground connection is completed through the distributor points then the distributor plate or, briefly, through the condenser to ground. My voltmeter reads good ground at the fixed post of the points, the spring plates that the points mount to, and the distributor housing. I set the point gap via the FSM spec, both ways it is specified in varying versions of the FSM (either by setting the point gap itself at .018" when they are at max open, or by setting the rubbing block gap to the post when the points are full closed and the cam face is flat). Just out of curiosity, I also tried setting the points to a smaller gap and larger gap - no changes, besides maybe some slightly different behavior in the sparking between the points. Once it got darker and I could see the spark between the points contact a bit better, I noticed that it was fairly erratic and sometimes looked as if it was arcing to the plates ground instead of across the points gap to ground. IDK if this is normal or not.

In any case, I couldn't get a spark with the spark strength tester when cranking the ignition and spinning the dizzy shaft. The only time I could get spark with everything hooked up to the distributor, and I'm not really sure why, is if I use a screwdriver to physically separate the points then simultaneously ground the screwdriver to the plates. If I use a screwdriver to open the points and then close them, without grounding the moving point arm with the screwdriver to the plates, then I get no spark...no matter how slow or quick I do it, or how small or big I try to open the gap.

So, I was thinking of removing the distributor from the engine and repeating the same test off the vehicle with it spun by a drill or by hand. I could dial in the points gap a bit easier this way too. If I get good spark this way, then I know the distributor system is all good in terms of spark generation and my problem likely lies in a grounding issue in the vehicle somewhere.

Thanks! Yesterday was hella frustrating. I thought I was making progress, but now feels more like I'm just spinning my wheels.

p.s. I also checked the input / output voltage at the external regulator and alternator with the ignition on and they checked good. I inspected all the connections and wiring into and out of these two as well and all seems correct per wiring diagrams and a few forum posts to confirm.

 

[45Dougal]

Have you tried sanding your points faces with a fine sand paper to clean them up?

Take them out and give them a good clean scrubbing off any residual carbon that may be deposited around them.

 

[bdsmitty88]

Have you tried sanding your points faces with a fine sand paper to clean them up?

Take them out and give them a good clean scrubbing off any residual carbon that may be deposited around them.

The points are only a month old...so they've only been used for testing and no actual driving. But, regardless, I did clean then with sand paper yesterday with no change.

 

[45Dougal]

The points are only a month old...so they've only been used for testing and no actual driving. But, regardless, I did clean then with sand paper yesterday with no change.

They shouldn't be sparking, and certainly not arcing to ground.
If your condenser is in good condition, that doesn't leave many things to try.

You said that your voltmeter measures a good ground at the points plate and the post when closed.

What do you mean by that exactly? You measured voltage between the battery negative terminal to those places??

Switch your meter over to resistance/ohms and measure the resistance between the post and the battery negative terminal when points closed. Also measure from the points plate to battery ground.

Sounds like you might have a poor ground connection at the dizzy