Ignition questions (1 Viewer)

[lenmn]

1976 US Spec FJ40. Replaced direct drive starter with a reman Gear Reduction Starter 28100-60070-84. Did not add ground to frame strap. Have starter ground kit on order from Vintage Teq Parts.

New battery. Cleaned all terminals and grounds.

Has a pertronix ignitor module in dizzy and has never had any issues.

Started after 4 consecutive cranking attempts. Let trunk for at least 20 minutes. An hour late started first crank. Much faster revolutions than original as expected.

The next day and since it did not start. Cranks fine. Thought I flooded it so waited, tried again, tried all sorts of techniques to no avail.

I won't share the rabbit hole I then went down, but verified ballast and coil primary and secondary resistance were within nominal range. Voltage at ballast with ignition on. Did spark test from coil secondary to block and saw blue spark across plug gap. Did spark test from coil to distributor to pulled spark plug with remote start from battery to starter solenoid (wire from ignition disconnected) and not only had spark but she fired right up and ran on 5 plugs in the motor. Reconnected the starter solenoid to the ignition wire Jumped 12 volts from battery to coil and it started and ran great even after removed the jumper cable (used the remote switch with button held down).

The helper signal from the original starter is not used. Maybe this is why it started with the original starter but with a defective switch/wire from to the ballast/coil because it provided the battery voltage to the coil when the switch didn't during crank?

So now, when the key is switched to start/crank the voltage at the ballast/coil is 0 volts. This is the same black/yellow wire that carries the ignition voltage to the ballast/coil. This is with the starter solenoid connected or disconnected from the ignition start wire.

Shouldn't the black/yellow wire from the ignition be at battery voltage when cranking so the coil is fired?

1. Is it most likely the ignition key cylinder?
2. Or the wire harness from cylinder down the steering column, which btw looks like it was replaced by a PO?
3. Other?

Appreciate you all and this forum. Thanks in advance for any help. I won't be able to do any more tests until next week as I'll be on travel.

 

[Grayscale]

There are two black/yellow wires near my '75 coil. One is about fourteen-gauge, the other is about eighteen. The fat one is connected to the coil resistor, the other bypasses it.

 

[lenmn]

Thanks Grayscale. I have both those wires on my 76. The bypass was connected to the old direct drive starter to bypass the ballast provide 12V to the coil during start. The gear reduction starter does not provide that signal and so that wire is not connected.

The problem I am having with the gear reduction starter installed, is that when I turn the key to start the voltage on the bigger black/yellow wire goes to zero volts to the ballast/coil and so the coil cannot deliver the high voltage to the dizzy to create a spark. The starter cranks but that's it. If I jumper 12 volt from the battery to the coil it starts . When the key is then released to the ignition/on position the ballast/coil is getting the 12 volts and it runs fine even with the jumper removed as the ignition is now providing 12 volts to the ballast/coil as it should.

The question is, shouldn't battery voltage (12 volts) be provided to the ballast/coil during start/crank? I am thinking the ignition key cylinder is shot or the ignition switch cable that runs down the steering column has a contact problem. I inspected and cleaned the contacts at on the harness connector under the dash. I read in the 60's forum that it could be the contacts on the end of the harness that mates with the key lock cylinder.\

I think my next steps will be to remove the plastic around the steering column, remove the key cylinder and inspect. Also ohm out the harness.

 

[Grayscale]

I'm thinking that you might be experiencing an ignition switch problem. The lock cylinder is not electrical, just mechanical.
It sounds like an ignition switch issue.

 

[MatthewMcD]

First, rule out your ignition switch. Not too long ago I removed mine and cleaned it up. I had to "jiggle the keys" every so often that lead me to the rebuild. It was tedious with the little ball bearings and springs, but not horrible.

 

[lenmn]

MatthewMcD, do you mean the switch wire harness?

 

[MatthewMcD]

Yes, on mine that plastic cover came off and it was full of greasy sand. The copper contacts were corroded too.

 

[lenmn]

Thanks, very helpful. I'll look at this next and hold off on removing the key lock cylinder.

 

[MatthewMcD]

Thanks, very helpful. I'll look at this next and hold off on removing the key lock cylinder.

Start with a multi-meter and your FSM, you should have no continuity in the off position, then ACC, ON, and ST. If all that is working and it's not "crunchy" when switching, you may be able to rule out the rebuild (or verify the switch issue). FSM also has the removal steps if you need to pull the cylinder.

 

[lenmn]

Start with a multi-meter and your FSM, you should have no continuity in the off position, then ACC, ON, and ST. If all that is working and it's not "crunchy" when switching, you may be able to rule out the rebuild (or verify the switch issue). FSM also has the removal steps if you need to pull the cylinder.
View attachment 3865392

Awesome, that is exactly what I need! I don't have the FSM just for Emissions and Engine. Going to look for that.

 

[MatthewMcD]

Awesome, that is exactly what I need! I don't have the FSM just for Emissions and Engine. Going to look for that.

The 1975 FJ40 Chassis Manual is in the Resources section of this site. Free PDF download.

FSM - 1975 FJ40, FJ43, FJ45, FJ55, BJ40-43, HJ45 Chassis-Body-Manual

PDF

forum.ih8mud.com

 

[lenmn]

Sending a Big Thanks to @MatthewMcD and @Grayscale. You guys were spot on.

Confirmed the ignition switch is not operating correctly. Effectively has an open circut at the start position (hence not voltage to IG during crank). And it is not an OEM/Toyota part. Replaced it with Toyota part 84450-60070 and the rig started immediately on first crank.

Since my FJ40 has the ballast resistor and no longer has the bypass connection from the original starter, replaced with GRS, I picked up a relay and may install another time as a precaution.

Learned a ton in the process of diagnosing the ignition issues.

 

[MatthewMcD]

Sending a Big Thanks to @MatthewMcD and @Grayscale. You guys were spot on.

Confirmed the ignition switch is not operating correctly. Effectively has an open circut at the start position (hence not voltage to IG during crank). And it is not an OEM/Toyota part. Replaced it with Toyota part 84450-60070 and the rig started immediately on first crank.

Since my FJ40 has the ballast resistor and no longer has the bypass connection from the original starter, replaced with GRS, I picked up a relay and may install another time as a precaution.

Learned a ton in the process of diagnosing the ignition issues.

Outstanding, plus you get extra points for letting us know you fixed it.