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FZJ80 starting woes

Romer

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Just saw this video on YouTube where you can buy a blade type 1 amp diode that will allow your charging voltage to increase for your AGM batteries.

He put a link in the description where to buy the diodes.

I bought one of those for the 200. Before that I would charge the batteries before going on a trip to make sure both were topped off or after sitting for a few weeks.

On the NFT connectors. I recall those being over the tranny and not the starter, but I havent had an 80 in 11 years so could be mistaken
 

Stuckinthe80s

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Because I've been knee deep in starting circuit schematic tracing, I thought I would add to this for discussion purposes.

Here is the schamatic for the starting circuit for a 1994:
1646626393330.png


And one for a 1996:

1646626474933.png


Circuit Opening Relay circuit from 1994:
Circuit Opening Relay 1994.png


I forgot to note that the yellow-red wire is from the EFI relay. And note that the AFM keeps the coil charged on the circuit opening relay after starting.

So in the case of starting woes, if you keep it to the three things you need to fire an engine: air, fuel, spark, then some of the culprits can be:
  • We can rule out air because there isn't an electrical association with air, at least on starting. The AFM will keep the circuit opening relay charged (after the engine is running) to continue to let the fuel pump run.
  • Fuel can be limited if the circuit opening relay isn't being charged appropriately. The charged side is coming from the starter circuit during startup.
  • Spark is coming from the key switch to send power to the igniters.
  • Crank power to the starter is being supplied from the switch via the neutral safety switch (park neutral position switch)
So it looks like you weren't wrong, @RayRay27 in switching out your nsw.

Matt @Hulk , I'm assuming you wired your push button somewhere after the NSW? The tell tale sign would be if you put it in gear, push the button, and your truck started moving. I'm curious about this because I had to think through it during my 2uz swap. The 100 series has a starter relay, not a circuit opening relay, so I had to figure out how to get a proper signal to the starter AND send power the fuel pump during crank. I thought about tapping in at IH1, pin 15 for the starter signal but I didn't really want to bypass the safety stuff.
 

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Stuckinthe80s

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I just re-read through this whole thread again. Sorry if I'm inducing noise to the discussion but I was pretty proud of myself for working through this on paper at least.

To make sure people aren't mixing up issues:
The symptom that started this thread was - turn key, no crank, no clicky clicky, so lack of fuel is not part of the equation.
 

dan1554

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Just saw this video on YouTube where you can buy a blade type 1 amp diode that will allow your charging voltage to increase for your AGM batteries.
Thanks for this, I just bought one. I think this is what @Inukshuk was telling me about on our last trip. Hoping it improves the charging of my lfe battery.
 

Inukshuk

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Thanks for this, I just bought one. I think this is what @Inukshuk was telling me about on our last trip. Hoping it improves the charging of my lfe battery.
What one did you buy?
 

Inukshuk

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RayRay27

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I bought like six of them so if anyone needs one let me know. They should be here next week.
 

dan1554

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@Inukshuk I need to read in to it more, but if I can I think I'll add an in-line fuse holder on that circuit so it'll still have a fuse.
 

Inukshuk

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@Inukshuk I need to read in to it more, but if I can I think I'll add an in-line fuse holder on that circuit so it'll still have a fuse.
I'll bring mine this weekend.
 

DaveInDenver

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Regarding the diode thing.

You can get them from a Ford dealer, part number is 4F2Z-14A604-AA and typically about $6. All they are is a 1N4004 potted in a fuse shaped body.

The actual manufacturer is Littelfuse.


Nice thing about the Ford version is it's designed to fit so no need to clip the corner. It's already tapered to fully seat, at least in the Delphi fusebox Toyota used in my Tacoma. The GM and Littelfuse need a slight mod.

IMG_0175_mid.jpg

IMG_0174_mid.jpg

BTW, if you replace ALT-S with this like I show in the photo that leaves the circuit unprotected. The 1A rating is a current limit, they aren't designed to fuse but a diode will eventually burn up.

There was a guy on Tacomaworld who watched it with a thermal camera and it does get fairly warm but I don't know if anyone's actually measured the current in the circuit. All you can say is it's less than 7.5A of the original fuse!

I ended up building a little different set-up using an Add-A-Fuse that loops around on itself with a regular 3A diode and 10A fuse.

IMG_1270_mid.png

IMG_1464_mid.jpg

But I ended up going back to the stock system. All this hack does is add a diode drop in the alternator sense line. It will bump the regulated voltage but it's still not right. I ended up going too far over with an 1N4004 (that Ford one measured 0.65V drop) overcharging on the highway. I experimented with Shottkys at around 0.3V and that wasn't enough. It's adding a variable in the control loop so the alternator may be thinking it's a fault. On a 3rd gen Tacoma this trick doesn't work at all since it's got a smart alternator and the ECU just figures it out.

Per Odyssey (my AGM brand) the ideal charging voltage is 14.7V at 25°C with a temperature compensation of -24mV/°C.

So the ideal charge temperature at 40°C would be 40°C - 25°C = +15°C * -0.024V = 14.7V - 0.36V = 14.25V. On the flip side when it's cold the ideal charging temperature goes up, so at 10°C it would be 10°C - 25°C = -15°C * -0.024V = 14.7V + 0.36V = 15.06V. So "right" is a moving target.

I was lucky Odyssey warrantied mine (it was just 2 years old). It actually went kaput on a trip to the Dollhouse with Jeff and Nic but I don't know if it was an acute or cumulative issue. I only ran with the diode in for about 3 or 4 months, Jan to April 2019. YMMV

IMG_1578_mid.png
 
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RayRay27

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I got 5 of these now if someone is looking to do this in their 80.
20220311_201327.jpg

20220311_201337.jpg
 

Hulk

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Inukshuk

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This past weekend on the pre-run I experienced hot and cold no-starts. Mostly a jump start worked (going from 12.5 to 13.5 volts b/c other truck was running. Jumper packs useless).

On drive home when it did not hot start at lunch @jps8460 and I took two additional diagnostic steps (1993 80). We could hear a click at the starter but the starter motor was not turning (i.e. "no crank"):
1) confirmed 12.5 V at connector from ignition circuit (we unplugged this from the starter)
2) ran a wire straight from battery + to starter solenoid ignition connection (the one unplugged in #1 immediately above) while key was in "run" position. It started right up and every time. (FYI @jps8460 my research (not guaranteed, is that the solenoid coil current is around 14Amps. I can test that with my clamp meter one day)

Turns out, "click, no crank" does not always mean a bad battery OR a bad starter. Read on ....

Considerations:
  • I rebuilt this starter last month
  • Big Odyssey battery two years old has 12.5-6 resting volts.
  • Ignition switch about 2 years old
  • starter battery cable a few years old. Good welding wire with crimped and sealed ends.
  • Grounds are good.
  • Starter solenoid ignition connection terminal housing locking tab is busted. I had it held in place with zip ties. So, while it was not disconnected, I have a new Toyota one (connector housing 90980-11400) to assure positive lock.
  • No corrosion but dielectric grease in the connection. Jackson commented he likes to apply that to the sealing gaskets of a connector, not the metal electrical bits because in some circumstances - esp with older less springy connections - grease can physically push apart electrical contacts. After reconnect with less grease it worked once. But later it did not.
  • I have a new Toyota starter terminal repair pigtail (repair terminal with wire 82998-12480) on order. $7.01. This is the metal connection that goes into the housing.
(You can find housings with pigtails on E-bay and Amazon for about $15 but the OEM housing plastic is going to last a lot longer. It already lasted 30 years)

BUT most likely my problem is a 2.0kW plunger in a 2.2kW starter.
The slightly different 2.0kW plunger in a 2.2kW starter is known to work when cold and not so much when hot. (The resistance of a solenoid coil will measurably change based on temperature (room temperature compared to 200°, as an example). As a result of the temperature rise, the solenoid coil resistance will increase, which will in turn reduce (increased resistance decreases current flow) the current draw resulting in lower available push or pull force. Here, the wrong plunger is mostly ok when cold but is not being pulled/pushed enough when hot)
fzj80-starter-plunger-differences-jpg.3278163
I have a 2.2kW plunger on order (28235-35080, plunger magnet switch, $37.88)

Some things I learned that may come in handy on road or trail one day with a no-start rig automatic transmission rig. After other typical diagnostics:
1) unplug IGN circuit connector at solenoid and check for voltage when key in start position. Compare that voltage to battery voltage for no voltage or amount of drop.
Toyota starter motors and gears do not cease to work nearly as frequently as contacts and plungers, and there are ways to bypass the contacts:
2) With key in "on" position and engine cleared of body parts so you can start the truck, touch a jumper a wire (small wire is ok) from batt+ to starter solenoid connection. This may start truck.
3) With key in "on" position and engine cleared of body parts so you can start the truck, touch jumper cable (you need big wire here) from batt + to starter motor + (bypassing the solenoid and contacts). Alternatively if you don't have jumper cables you could disconnect the battery wire at the solenoid and touch it to the starter motor, or find some way to make a short jumper there (but a lot less space to work with)

After all of the above, if I ever have a start problem I will wire in a relay to take the solenoid current off the ignition switch circuit. Later years have relays to fire the solenoid. (http://www.4crawler.com/4x4/CheapTricks/Starter.shtml#OtherOptions)
 

subzali

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This past weekend on the pre-run I experienced hot and cold no-starts. Mostly a jump start worked (going from 12.5 to 13.5 volts b/c other truck was running. Jumper packs useless).

On drive home when it did not hot start at lunch @jps8460 and I took two additional diagnostic steps (1993 80). We could hear a click at the starter but the starter motor was not turning (i.e. "no crank"):
1) confirmed 12.5 V at connector from ignition circuit (we unplugged this from the starter)
2) ran a wire straight from battery + to starter solenoid ignition connection (the one unplugged in #1 immediately above) while key was in "run" position. It started right up and every time. (FYI @jps8460 my research (not guaranteed, is that the solenoid coil current is around 14Amps. I can test that with my clamp meter one day)

Turns out, "click, no crank" does not always mean a bad battery OR a bad starter. Read on ....

Considerations:
  • I rebuilt this starter last month
  • Big Odyssey battery two years old has 12.5-6 resting volts.
  • Ignition switch about 2 years old
  • starter battery cable a few years old. Good welding wire with crimped and sealed ends.
  • Grounds are good.
  • Starter solenoid ignition connection terminal housing locking tab is busted. I had it held in place with zip ties. So, while it was not disconnected, I have a new Toyota one (connector housing 90980-11400) to assure positive lock.
  • No corrosion but dielectric grease in the connection. Jackson commented he likes to apply that to the sealing gaskets of a connector, not the metal electrical bits because in some circumstances - esp with older less springy connections - grease can physically push apart electrical contacts. After reconnect with less grease it worked once. But later it did not.
  • I have a new Toyota starter terminal repair pigtail (repair terminal with wire 82998-12480) on order. $7.01. This is the metal connection that goes into the housing.
(You can find housings with pigtails on E-bay and Amazon for about $15 but the OEM housing plastic is going to last a lot longer. It already lasted 30 years)

BUT most likely my problem is a 2.0kW plunger in a 2.2kW starter.
The slightly different 2.0kW plunger in a 2.2kW starter is known to work when cold and not so much when hot. (The resistance of a solenoid coil will measurably change based on temperature (room temperature compared to 200°, as an example). As a result of the temperature rise, the solenoid coil resistance will increase, which will in turn reduce (increased resistance decreases current flow) the current draw resulting in lower available push or pull force. Here, the wrong plunger is mostly ok when cold but is not being pulled/pushed enough when hot)
fzj80-starter-plunger-differences-jpg.3278163
I have a 2.2kW plunger on order (28235-35080, plunger magnet switch, $37.88)

Some things I learned that may come in handy on road or trail one day with a no-start rig automatic transmission rig. After other typical diagnostics:
1) unplug IGN circuit connector at solenoid and check for voltage when key in start position. Compare that voltage to battery voltage for no voltage or amount of drop.
Toyota starter motors and gears do not cease to work nearly as frequently as contacts and plungers, and there are ways to bypass the contacts:
2) With key in "on" position and engine cleared of body parts so you can start the truck, touch a jumper a wire (small wire is ok) from batt+ to starter solenoid connection. This may start truck.
3) With key in "on" position and engine cleared of body parts so you can start the truck, touch jumper cable (you need big wire here) from batt + to starter motor + (bypassing the solenoid and contacts). Alternatively if you don't have jumper cables you could disconnect the battery wire at the solenoid and touch it to the starter motor, or find some way to make a short jumper there (but a lot less space to work with)

After all of the above, if I ever have a start problem I will wire in a relay to take the solenoid current off the ignition switch circuit. Later years have relays to fire the solenoid. (http://www.4crawler.com/4x4/CheapTricks/Starter.shtml#OtherOptions)
I wonder if this is the root cause of the problem I experienced last summer with my 96. I had rebuilt the starter and it was not giving me good hot starts. I ended up just replacing the starter with a unit from Carquest, and returned the core, so we'll never know. But that's good to know about making sure the right part numbers are used in either case.
 

Inukshuk

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I wonder if this is the root cause of the problem I experienced last summer with my 96. I had rebuilt the starter and it was not giving me good hot starts. I ended up just replacing the starter with a unit from Carquest, and returned the core, so we'll never know. But that's good to know about making sure the right part numbers are used in either case.
The plunger only if you had already replaced your starter with a 2.2kW because the 2.2kW was only available in some 1993 models.
The resistance issue in general, possibly. Parts do wear out. Even wires.
 

subzali

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The plunger only if you had already replaced your starter with a 2.2kW because the 2.2kW was only available in some 1993 models.
The resistance issue in general, possibly. Parts do wear out. Even wires.
Maybe I just screwed up the rebuild in general :ROFLMAO:
 

subzali

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Just had a hot no-start today. So will be going down the troubleshooting path. Last year had troubles and ended up replacing the alternator and starter I believe.

Turn key all lights are on hear a clunk but no turning over.

Diehard Platinum AGM and it’s at 12.24V with the vehicle off right now.

It’s been sitting a little bit over the past couple of weeks but it did start twice today to run to the eye doctor and back. Then the 3rd time I tried to start it today when it was hot it just didn’t.

EDIT 7/20/23 AM: Just tried a cold start with the battery voltage at 12.06V and successfully started.

EDIT 7/24/23 AM: 11.95V successful cold start.

EDIT 7/25/23 PM: have had the battery on the charger for a couple days. Resting voltage is at 12.65V.

EDIT 8/3/23 PM: after charging the battery and reconnecting have been driving for a few days with no issues, including good hot re-starts. Then had a hot re-start issue yesterday. After trying the key 5-6 times it caught and I was able to get home. Resting voltage is 12.44V.
 
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Inukshuk

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Just had a hot no-start today. So will be going down the troubleshooting path. Last year had troubles and ended up replacing the alternator and starter I believe.

Turn key all lights are on hear a clunk but no turning over.

Diehard Platinum AGM and it’s at 12.24V with the vehicle off right now.

It’s been sitting a little bit over the past couple of weeks but it did start twice today to run to the eye doctor and back. Then the 3rd time I tried to start it today when it was hot it just didn’t.
Sorry to hear but it’ll also be a great opportunity for diagnostics for everybody.

I’ve had zero issues since putting on the new terminal and connector. Starter spins strong.

Get the new terminal ( connector is not a bad idea while you’re in there) before anything else.

Meanwhile, if you have a hot start problem before your new terminal arrives, run a wire from the battery, straight to the solenoid with the key in the on position and see if that starts it.

I reread my post above and should also have pointed out that I had a fair number of hot start problems with a 2.0 kW starter for years after replacing the ignition switch and before replacing the terminal.

  • New Toyota starter terminal repair pigtail (repair terminal with wire 82998-12480) $7.01. This is the metal connection that goes into the housing.
  • Toyota connector housing 90980-11400)
(You can find housings with pigtails on E-bay and Amazon for about $15 but the OEM housing plastic is going to last a lot longer. It already lasted 30 years)

Turn key all lights are on hear a clunk but no turning over.
= current to the solenoid is inadequate through the connection at the solenoid, moves the plunger a bit, but not enough.

And your starter is new, so we know its not likely a bad starter!

Look forward to results!
 
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