Removed ballast resistor and weak spark?!!! No cranky.

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wimberosa

wimberosa

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Durango Colorado
...the continuing saga of "I thought I knew what I was doing" ....

@Pin_Head @fjc-man

Details:
Model Year: May 1979.
Original dizzy with oem electronic signal generator.
Coil specifies: use w external resistor
Coil TEQ part number: 90919-02083
Igniter part number: 19070-61031
Has complete smog with computer
I live in a cold climate.

Background:
A few weeks ago I suffocated my carb accidentally and flooded it badly and fouled the plugs. I've been checking out a few things after that (see the dizzy vacuum advance rebuild thread), checking my valve lash (cold), and preparing to time the 40. I thus pulled and re-stab'd the dizzy and am pretty sure I'm a few degrees advanced off TDC just due to re-stab by eye alignment. All this was just following the FSM and I'm sure I'm on the compression stroke for #1 when I lined all this up. But timing light has not been applied yet. I have turned the starter over a bunch and had it crank a few times but too high of an RPM (perhaps due to vacuum leaks as I had the air cleaner off and some hoses undone).
Problem:
I can't get it re-cranked and I appear to have removed my ballast resistance.

My current hypothesis:
It looks like my spark is weak. I'd applied the timing light to #1 and turned it over a few times but wasn't getting a reliable blink. I got the first blink ok but then a weak one and then nothing on the light (ok...thats odd). I then pulled #1 plug to watch the spark. I got a decent spark on the next crank of the first revolution but then the spark appears to get weaker and weaker. Not blue...yellow and weak.
I'm guessing coil or bad ground in my coil/igniter area. I added a second straight wire ground from coil/igniter mount to where my battery connects to the frame and thats not the issue. So I tested my resistance on the coil

Coil tested primary resistance: 1.7 ohm
Tested secondary resistance: 13.27 ohm

1980 2F Engine Late FSM:
Spec primary resistance: 0.5 to 0.7 ohm
Spec secondary resistance: 11.5 to 15.5 ohm

To me that looks out of spec but the 1979 is such a freaking odd bird that I'm not sure if I'm using the correct spec. Here's where things got really odd. I'm checking the manual and the wiring diagrams and knew I didn't have a visible ballast resistor.

Looking back through mud posts I see that @Pin_Head makes mention of a Yazaki pink wire in the 1979 wiring harness at post.
Pin_Head

Post in thread '1979 FJ40 no spark issues (I have read all the threads on this issue) What am I missing or failing to check'

Chances are that the black/yellow stripe wire under the starter is the resistor bypass wire and it should not be grounded. The PO may have changed the starter to the type that does not have the bypass connection. There should be another black/yellow stripe wire near the coil that ends in a ring terminal.

The ballast resistor is built into the wire in ‘79. It is the so-called “Yazaki” wire for the name labeled on the wire.

You don’t need the bypass circuit, especially if you don’t live in the snow country.

You do need to check that the voltage at the igniter does not fall below...

Alarm bells are ringing!!! I had a pink thick wire in my wiring harness which I removed. My harness was a bit toast and had odd patches in it. I never saw this as a plausible wire in the wiring diagrams that I was using from @Coolerman web site for the 1979. I mean what the heck is toyota using a pink wire of vastly different gauge in the harness for? I think I know now that its a resistance wire replacing the external resistor before the coil.

Question:
Is the missing resistance wire before the coil a plausible culprit for causing a downstream coil problem and my weak spark? Is the coil even a likely culprit here for this weak spark?

Solution Directions:
I'm a bit loathe to pull the wiring harness back out from under the dash and add a resistance wire....so I guess I could go with an external resistor. I'm trying to look very close to stock for this rig but could also possibly go to a higher wound 12v coil which I think might get me the same thing as a ballast resistor. What the specs for such a coil would need to be I'm not sure. Also not sure if I've screwed anything else up downstream such as my electronic signal generator in the dizzy. Note: I believe I understand in a shallow manner that the ballast resistor is there to protect that coil during normal running by dropping the volts. Its bypassed during cranking to give the full 12v. I'm thus wondering if I've incrementally toasted my coil to where it produces a weak spark by not having the resistance protection.

A few pics of what I've got. I can't remember where that pink wire truly was but I have a snippet
photo of it connected to black/yellow wires:

1770247727366.webp


IMG_4389.webp
 
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I think the resistor is to tone down the spark when running by dropping the voltage to the coil. When starting, the coil gets the coil gets full voltage for the hotter spark. That's how mine works, but I run a different set up.

Pull the plug wires at the cap and check for corrosion on the wire and inside where it plugs into the cap. If you have aluminum contacts in the cap, look at them - they will develop a thick layer of aluminum oxide (an insulator) contributing to a weak spark - I use the small blade on a Swiss Army Knife to scrape the inside contacts clean. You can scrape the rotor bug also. Clean the contacts inside the spark plug boots too.

How old are your plug wires? The do go bad when they get old. When you get it running go out on a dark night and look for dancing fire off the wires, if you see that you need new wire.

Things work better with the dizzy in the correct position.
 
On my desmogged 79 project, I've been where you are with your ignition situation/symptoms and it's not a fun place to be. But, it all worked out...eventually!

In my case, I found the schematic critcal to verify and correct wiring issues, and the FSM really handy in testing the various ignition components beyond the coil including ignition power (coil +), the igniter and the distributor pickup.

But first, I would go back to basics starting with verifying your static timing is close, verifying you have 12v at coil+ while cranking, and making sure you're getting fuel and spark, even weak spark.

If you can't get that, you'll have a focus for further troubleshooting. If you suffocated the carb, it's possible some junk clogged things up, including the idle mixture and idle cutoff. A little squirt of gas down the carb when cranking can help determine that.

Once you get it to start, even roughly, then you can get the timing light out, adjust your carb to the FSM, and dig deeper into the ballast and bypass wiring issues you mentioned to square that all away.

Getting to specifics, without a resistor wire or ballast resistor feeding your coil +, yes, it's possible damage has been done to your igniter, but your FSM tests should show that. Not sure you should substitute a modern coil (internal resistor) with your 79 igniter. That igniter likes 7v going down the road. If you want to continue with your resistor wire delete, you could upgrade to a later FJ60 igniter and coil that work fine with continuous 12v and no bypass circuit.

My 79 got spark, but failed the igniter FSM test and the pickup FSM test. I also had a sloppy distributor, that made for some intermittent spark issues. Drove me a little crazy until I figured that out.
 
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The easy way to check you are at TDC #1 is both valves will be loose at the adjustment - the piston will be up top looking into the spark plug hole and the line is on the indicator in the window. Put the rotor bug pointing towards spark plug hole #4 (if the dizzy was installed) actually it will be the #1 wire in the cap. Look at the dizzy shaft's flat on the bottom - align the oil pump gear to that same angle so the tab of the dizzy shaft will slide into the oil pump gear.

Stab in the dizzy, the rotor bug will move as the dizzy seats - it should be pointing at #4 spark plug just as the book shows. Be sure the dizzy shaft is in the oil pump gear. that is the dizzy is fully seated or you will not get oil pressure even if the engine runs.

Put tranny in neutral, chock the wheel or set the brake. Pull all the spark plugs. Use a remote ignition switch to engage the starter while pressing down on the dizzy - you will feel the dizzy drop into the oil gear if it wasn't before. Tighten the clamp. Use key to engage the starter - whirl the engine over for 30 seconds or so. Watch oil pressure gauge, if it doesn't start reading pressure by the 4th cycle you could have a problem. After you see oil pressure, put the plugs in. Hook up the timing light and see if it will start - move the cap around and watch the light. Does it run?

You can easily be one tooth off. Bump the engine back to TDC #1 compression with the remote switch. I just grab the metal fan blade and pull, loosen clamp, take dizzy cap off, rotor bug will be pointing towards #4 spark plug. As you pull the dizzy the rotor will move - grab rotor and turn it that amount to advance or retard one tooth. Push the dizzy back down and watch the rotor. it should be pointing at a little different spot near spark plugs #4. Key is Off. Press down on dizzy while while engaging the starter with remote starter switch, you will feel the dizzy drop into the oil gear. Tighten clamp. Use key and see if it will run and quickly build oil pressure. Adjust the timing. If you have points they should be set correctly before you start.

If you have a brain box, and it fires only once as you let off the key - that the sign its bad.

When you get it running correctly - put the engine at TDC#1 compression, remove the cap - lay a straight edge on the rotor and use a paint pen or "white out" to mark both the dizzy housing and the spot on the engine. Before you pull the dizzy again make the marks are still there.
 
I don’t have a 2F. But isn’t the ballast resistor only used to drop the voltage to the coil so you don’t burn out the points prematurely.
If you’re running electronic ignition then I would think you don’t need a resistor. Most modern coils can handle the 12 volts. Hmm. But I know nothing about the 2F ignition. I only play with V8’s. Chevy or ford. When I removed points on those old engines I removed the ballast resistor. Unless you’re not talking about the ballast resistor.
 
I fought the same ignition system on my 1978, replacing coils, igniters, and pickups before ultimately changing out my distributor to a non-US spec Toyota distributor with a pertronix, pertronix flamethrower coil, and a relay kit (to get full power since I likely have that same pink resistor wire you removed). My symptoms were different through. It would start slow, but start, but as soon as it started to get warm it would shut off, and wouldn't turn back on.
 
I'm not having dizzy stab issues as I had the valve cover off and knew I was on the compression stroke for #1. I have the advance all marked with a paint pen. I just moved it slightly back off my marks because I knew I was going to time it and I'm already going to be 3 degrees advanced because the HAC now works and will kick in as I'm at 7k feet. Yes...yes the FSM says unhook BOTH ported and HAC vacuum advance but I think its appropriate to unhook only the ported advance. If I time it at 7k' and don't have the HAC port connected and get my timing perfect with optimal vacuum .... then when I hook up the HAC it will jump another 3 degrees advance which I don't want. I think its better to time it with HAC port connected for me.

I'm pretty sure I removed this yazaki resistor wire and have been studying both the hayes and teq wiring diagrams this morning. The wiring is a bit befuddling in those diagrams versus "boots on the ground" harness that toyota wired up (the engine section of my harness is unmodified). My read on the diagrams is that it appears as if the coil electrical flow is reversed during starting. The harness supplies two b/y wires into the igniter/coil setup. The thicker gauge b/y appears to be the one that should have resistance and is connected to the positive side of the coil. This is the path during normal runs. The thinner gauge b/y should not have resistance and is connected to the igniter and then ultimately to the negative side of the coil after passing thru the electronic panel in the igniter board. This path appears to be used during starting with the thicker gauge now doing double duty with sending spark back to the starter. (As an aside this may be why the teq electrical diagram shows the coil having (+) on both sides of the coil in the diagram...I thought that was a typo...but maybe they are saying that sometimes the flow reverses direction for startup)

TODO this afternoon is to hook this back up and run thru the FSM procedures for testing the igniter and check my resistance to ensure what I remember about removing this pink wire matches with what I find. I also plan on shooting a bit of ether into the carb (as per @CruiserInProgress suggestion) and making sure that its really spark and not lack of fuel in the carb. I definitely suffocated the carb a few weeks back and haven't made any real progress on a proper run past that point. So maybe I really have junked up the carb someway.

I also have some new wires on order and will run through all the terminal cleanup on dizzy/wires/etc @charliemeyer007

Sometimes I feel like I make little to no progress other than uncovering other problems. I'd have never even fathom'd I'd done something wrong by removing this pink wire if I hadn't been down this rabbit hole.
 
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In medicine its "do no harm" - in mechanics its don't break things taking stuff apart - causing new problems. Just because you bought new parts doesn't mean they are good. Double check your work, easy to miss something when you are frustrated or tired. Before pic's and while doing are worth their weight in gold if you need to backtrack to solve an issue.

I like points and a carb - I can work with them with simple tools - no need for a $10,000 computer to try and tell me what it thinks is wrong .
 
wimberosa said:
I'm not having dizzy stab issues as I had the valve cover off and knew I was on the compression stroke for #1. I have the advance all marked with a paint pen. I just moved it slightly back off my marks because I knew I was going to time it and I'm already going to be 3 degrees advanced because the HAC now works and will kick in as I'm at 7k feet. Yes...yes the FSM says unhook BOTH ported and HAC vacuum advance but I think its appropriate to unhook only the ported advance. If I time it at 7k' and don't have the HAC port connected and get my timing perfect with optimal vacuum .... then when I hook up the HAC it will jump another 3 degrees advance which I don't want. I think its better to time it with HAC port connected for me.

I'm pretty sure I removed this yazaki resistor wire and have been studying both the hayes and teq wiring diagrams this morning. The wiring is a bit befuddling in those diagrams versus "boots on the ground" harness that toyota wired up (the engine section of my harness is unmodified). My read on the diagrams is that it appears as if the coil electrical flow is reversed during starting. The harness supplies two b/y wires into the igniter/coil setup. The thicker gauge b/y appears to be the one that should have resistance and is connected to the positive side of the coil. This is the path during normal runs. The thinner gauge b/y should not have resistance and is connected to the igniter and then ultimately to the negative side of the coil after passing thru the electronic panel in the igniter board. This path appears to be used during starting with the thicker gauge now doing double duty with sending spark back to the starter. (As an aside this may be why the teq electrical diagram shows the coil having (+) on both sides of the coil in the diagram...I thought that was a typo...but maybe they are saying that sometimes the flow reverses direction for startup)

TODO this afternoon is to hook this back up and run thru the FSM procedures for testing the igniter and check my resistance to ensure what I remember about removing this pink wire matches with what I find. I also plan on shooting a bit of ether into the carb (as per @CruiserInProgress suggestion) and making sure that its really spark and not lack of fuel in the carb. I definitely suffocated the carb a few weeks back and haven't made any real progress on a proper run past that point. So maybe I really have junked up the carb someway.

I also have some new wires on order and will run through all the terminal cleanup on dizzy/wires/etc @charliemeyer007

Sometimes I feel like I make little to no progress other than uncovering other problems. I'd have never even fathom'd I'd done something wrong by removing this pink wire if I hadn't been down this rabbit hole.
Click to expand...
It's been a while since I rewired my ignition, so I pulled up the portion of the schematic that I found most useful to this discussion.

It looks like the igniter does receive the full 12v for power (not reduced), whereas the coil + receives power through the resistor wire (and full power during cranking through the internal starter relay). So, Toyota must be protecting other ignition components via their use of the resistor wire (coil and/or distributor) in the 79.

Since I had multiple issues with my 79 oem ignition components (distributor and igniter) and parts availability, I opted to upgrade to a newer FJ60 ignition system (coil, igniter, distributor, dented pushrod cover, resistor wire delete). It made a huge difference in my desmogged 2F!

The good news for your situation, if your engine wiring is unmolested (except for your resistor wire delete), you can focus on testing individual components, and cleaning/verifying your many in-line connector pins and multiple ground points. I had issues with all of those.

I'm curious what you find with the carb/fuel (ether) test and the coil + voltage test while cranking.

Also, I assume that's the case, but just to confirm, when you deleted your resistor wire, did you reconnect both ends of the clipped wire, so that 12v from the ignition switch continued to use that heavy wire for the entire length to deliver 12v to your coil +?

Screenshot_20250223_201714.webp
 
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Hmmm.... More variables and it started with ether but RPM way too high. This time I'm predominantly hooked up with all vacuum hoses ... so no clear leaks. I let it run high for a minute and tried to bring it down with the idle speed screw (lower screw next to firewall). Turned it counter-clockwise which should have brought it down but it kept same high speed. Shut it off as it was a bit out of control on RPMs.

Additionally I got weird numbers on igniter and coil test again:
From Aug 1980 FSM USA Spec FJ tests:

FSM check 8-12: 9.99v Spec says should be: 12v
FSM check 8-13 1.12v Spec says should be: 12v
FSM check 8-16 1.9 ohm Spec says should be: 0.5 - 0.7 ohm
FSM check 8-17 15.2 ohm Spec says should be: 11.5 - 15.5 ohm

TODO: I'm pulling the carb off to see if something is sticking or gum'd up. I'll probably send it through my sonic bath with some pine-sol or simple green mix. Don't know much about carbs so if someone has an input on what to look for... then fire away.
 
The whole thing was kinda stuck in this position. No wonder the idle speed screw did nothing and it was over-rev'd. When I suffocated it....it flooded and then back fired through the carb on the next start attempt. I guess that caused this unhappiness.
1770336904477.webp
 
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CruiserInProgress said:
Since I had multiple issues with my 79 oem ignition components (distributor and igniter) and parts availability, I opted to upgrade to a newer FJ60 ignition system (coil, igniter, distributor, dented pushrod cover, resistor wire delete). It made a huge difference in my desmogged 2F!

I'm curious what you find with the carb/fuel (ether) test and the coil + voltage test while cranking.

Also, I assume that's the case, but just to confirm, when you deleted your resistor wire, did you reconnect both ends of the clipped wire, so that 12v from the ignition switch continued to use that heavy wire for the entire length to deliver 12v to your coil +?
Click to expand...

@CruiserInProgress As you can see above...I've got a carb that got a backfire bang on those lower butterfly valves and jammed that lower shaft. I'll have to see how this thing really is supposed to work and if a soaking and some fiddling with it leads me to some forward progress.

In regard to removing the pink wire. Its been quite awhile as the truck has been under rebuild for several years but I suspect I was checking continuity on the b/y wire and thought the pink wire was supposed to rectify some poor continuity. When I found it wasn't about continuity I probably just directly deleted it and connected the b/y wire up without it.

My igniter / coil is showing some strange values and am considering eventually going to the fj60 igniter/coil direction given poor spark and no pink wire. Was that effectively plug and play or does that fj60 setup have different plugs (ie. do you still have two b/y wires of different gauges in one of the plugs?). The dizzy looks like its using the same electronic signal generator so I'd probably keep my dizzy I've been working on. I do have a dented pushrod cover in my stash so I could probably find a fj60 dizzy if it really was necessary.
 
wimberosa said:
Hmmm.... More variables and it started with ether but RPM way too high. This time I'm predominantly hooked up with all vacuum hoses ... so no clear leaks. I let it run high for a minute and tried to bring it down with the idle speed screw (lower screw next to firewall). Turned it counter-clockwise which should have brought it down but it kept same high speed. Shut it off as it was a bit out of control on RPMs.

Additionally I got weird numbers on igniter and coil test again:
From Aug 1980 FSM USA Spec FJ tests:

FSM check 8-12: 9.99v Spec says should be: 12v
FSM check 8-13 1.12v Spec says should be: 12v
FSM check 8-16 1.9 ohm Spec says should be: 0.5 - 0.7 ohm
FSM check 8-17 15.2 ohm Spec says should be: 11.5 - 15.5 ohm

TODO: I'm pulling the carb off to see if something is sticking or gum'd up. I'll probably send it through my sonic bath with some pine-sol or simple green mix. Don't know much about carbs so if someone has an input on what to look for... then fire away.
Click to expand...
Congrats on identifying the carb issue! A good cleaning like you're planning, coupled with some forced air through various passages (with the top cover off) will help a lot. And verifying you have free and easy movement of your primary?

Your FSM coil/igniter test results seem similar to what I was getting with my problematic 79 oem setup. I remember for sure, failing the "power off" igniter test, suggesting the thing was on and drawing current all the time the ignition switch was on. Mine ran, but not well and I got arcing in the distributor cap. Not sure which was to blame, the igniter or the sloppy distributor or both.

I wasn't sure I was doing the tests correctly, but interestingly, when I upgraded to the FJ60 ignition, all those same tests passed.

About your question on the FJ60 igniter upgrade, it's not exactly plug and play. I seem to recall the distributor wire was the same, but one of the connectors at the igniter was not the same (due to no longer needing separate 7v and 12v lines from the harness). I think at least one connector and its wiring had to be changed. Not difficult, but you'll need to be careful to make sure power goes where it's needed, before firing it up.
 
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