Help! F135 Engine Ignition Problems (1 Viewer)

[eriditorum]

New to the board, so cheers to all.

Hoping you all can help me out. I'm have a problem with the ignition on a friend's 1965 FJ40 / F135 motor. Here is the skinny: We were driving along fine, when *snap your fingers* the FJ flat out died. Dead as a door nail on the side of the road, with no tools. Tried to restart the engine. Starter would turn over the motor, but the engine would not fire. Checked fuel line, ensured the carb was spraying fuel- all OK. Checked for air obstructions- none present. Checked the distributor, coil, and plug wires- all OK. Surmised that the problem was most likely an electrical issue in the ignition system. Ultimately I could not fix the problem on the side of the road, and we had to tow the FJ.

Now that the FJ was back in the garage, I pulled the distributor. Cap and rotor are almost brand new, and looked to be in great shape. Pulled the rotor and dust cover off, and noticed that the points were absolutely shot. So I replaced the points and condenser with parts from SOR. Reassembled / reinstalled the distributor, and reconnected the plugs and wires, thinking the problem fixed. Left the #1 spark plug out just to confirm a spark. However, when I turned over the engine, to my utter dismay, there was no spark arcing across the plug gap. So, the FJ is still dead, and I'm not sure where else the problem may be. Here are the troubleshooting steps I have taken so far:


Troubleshooting Done So Far:
1.) Replaced Points and Condenser With New Toyota Parts
2.) Tested Primary and Secondary Coil Winding Ohm Resistance- All Within Spec.
3.) Cap, Rotor, Spark Plugs, and Wires Are New Within Past 300 Miles. I Assume Them To Be Good.
4.) Replaced Corroded Coil Terminal Post Wires
5.) Checked Battery Connections, Chassis Ground.
6.) Checked Electrical System For Other Problems. None Detected.

After all that, still no spark. I'm at a bit of a loss. Any ideas where the problem may be? On a curious side note, I noticed that the needle in the stock Amp gauge no longer works- possibly related? Any help on this is greatly appreciated. TIA.

 

[FJ157]

same issue

i had a similar problem and it turned out to be my fuse block i pulled all the fuses and checked them with a meter cause one looked good but it was actually bad and then i took a wire brush and cleaned all the fuse holder prongs and it worked fine for about two weeks then it started again so i replaced my voltage regulator and it worked for about two weeks then i put in a new distributor and it worked ever since so i dont think i helped much but it is a place to start

 

[FJ40Jim]

Check for +12V power to hot (+)terminal of coil.

Check for pulsing volt reading at (-) terminal of coil when engine is cranking.

Let us know what you find.

 

[eriditorum]

First off, thanks for the replies. Much appreciated.

Okay, here is what else I have tried. I completely disassembled the fuse block, cleaned the fuse holders and terminal connectors, reassembled the fuse block, and installed new fuses. Tested the distributor cap contacts, distributor rotor contact, and the connection between the distributor rotor contact and the end of the rotor arm- all good. Checked the battery ground to the frame, and other grounding connections with the multimeter- all good. Checked the positive coil terminal for 12V- good. Checked the negative coil terminal for the opening and closing of the coil circuit- good, which indicates that the points are functioning. Turned over the engine, and the #1 plug is now getting an extremely weak spark. Too weak to fire the engine.

Something else to know. I have two coils available for testing- the stock Denso coil and a universal Accel coil. I have tested with both. With the Denso coil, the #1 plug does not spark. With the Accel coil, the #1 plug gets a very weak spark. To me, that indicates a potential problem with the cap and rotor- suggesting that it takes the increased voltage of the Accel coil to jump the gap between the rotor and the cap contact?

So is it time for a new cap and rotor? Also, does anyone know if the condenser ground grounds out through the shaft of the distributor? Thanks again for the help.

 

[eriditorum]

If anyone has other troubleshooting suggestions for my ignition woes, I am all ears.

 

[handcannon]

This is a long shot--- I re-read your posts and you say you checked the rotor for continuity. Was this in the dizzy or out? Several years ago my dad's PU died in downtown Albany.I went there to get it going again and almost pulled my hair out trying to find the problem. Turned out the rotor had shorted out to the dizzy shaft with no external visible signs. Hard to see. Replaced it and started right up. The day before dad and I had been over to central Oregon, 50+ miles to the nearest parts house, and I noticed then that he had to crank it a bit to get it started. Glad he was in Albany!

 

[jm599]

I think the coil bracket grounds the coil to the fender, have you made sure it is making good contact and not rusty?

 

[eriditorum]

Thanks again for the responses...

The rotor was out of the dizzy when I checked it. I will re-check it in the dizzy to see if the rotor is shorting out to the shaft. Thanks for the great suggestion. As for the coil, the bracket is mounted to the side of the head on the F135 engine. The bracket is in good shape and pretty much rust free. However, I will pull it off and clean up all the mounting surfaces just to cover the bases.

The FJ is still dead, so please keep the ideas coming. Even though this is not my rig, I kind of feel responsible for it since my buddy does not have a mechanical bone in his body *lol*. Cheers.

 

[Pin_Head]

The coil is only grounded from the - post through the points.

Check if the ignition cirucit is supplying enough power: run a jumper wire directly from the battery + to the coil + and check for spark. If you get a good spark and the engine runs, there is a high resistance connection somewhere upstream of the coil.

 

[FJ40Jim]

Still no spark out of the coil?

If there is power to the coil (there is)
and pulse from the points(there is)

Then the coil or condensor is bad.

 

[65swb45]

Or the wire that goes from the points terminal to the coil - is no good any more.

















Yes, it happened to me.............once.

 

[Ian Rogers]

cam gear?

 

[FJ40Jim]

Or the wire that goes from the points terminal to the coil - is no good any more.

He says there is pulse at the coil.

cam gear?

There is pulse at the coil, so the dissy is turning. If the gear is spun, the timing will be whacked, but spark will still happen.

 

[eriditorum]

Many thanks to all for the helpful replies!! I was finally able to fix the electrical issue in the ignition system. I started a bit of a shotgun gun approach this morning, so I am not sure what specifically resolved the issue. However, I have a feeling that a bad wire from the coil to the dizzy cap was a primary culprit. The suspect wire had very high resistance, where a spare wire I had had significantly less resistance. In all, I think the issue could be attributed to multiple problems, that manifested themselves as the ignition system not wanting to fire.

At any rate, now I need to make sure I am setting the timing correct. I created another post (see link) with this question, as I was afraid people would not bother to read to the bottom of this one to see my new question. https://forum.ih8mud.com/showthread.php?t=145720
Sorry- that's pretty tack forum etiquette, but I really want to get my buddy's FJ back to him. Thanks again for your expertise. Cheers.