The Engine Hesitation Saga

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Getting back to my FJ40. Someone mentioned I should replace the ignition condenser. This was an easy / cheap part replacement. I got a replacement condenser from trusted source (Parts Souq). but when I opened up the distributor, the configuration was different. This is what my setup looks like.

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when I pulled it out...this is how it looks ...

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My understanding is that the ignition condenser discharges to the points via the white wire. They are both connected to the mounting bolt; but looks like a local mechanic added a piece of plastic to isolate from the distributor body. The same bolt is also connected to the negative terminal on the ignition coil (red wire). Blue wire is the grounded.

Although the capacity was the same (0.22uF) the configuration was different, so I did not attempt to install the new one (with the yellow wire) and had to re-install everything back and re-adjust the dwell angel. its now 39 degrees (spec is 41 degrees +/1 1 degree). I might go back and try to get it closer.

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Unclear if the condenser is faulty / related to my occasional engine hesitation; but for now, I am just going to keep everything the same.

I also did change the fuel filter; but that was only cause I filled the tank and shortly afterwards the engine got very rough at idle. I think I need to clean the fuel tank, but dont want to remove the entire tank. Need to explore a simpler / easier approach.

Appreciate your inputs / guidance.
 
Check the resistance on your coil, if you're not running a ballast resistor should be about 3 ohms. Unhook the wire from coil to distributor then measure across the + and - terminals. If you're running a resistor the coil should be around 1 ohm. If you run one of these with no resistor you will rapidly fry your points.
I would be suspicious of your plug leads - your first misfire issue was after changing your rotor and distributor. Adjusting timing and carb sorted it but you may have made conditions for combustion much nicer, one may be dropping out when hot or under load now.
Do you run the truck daily? If its not getting regular use you will have to crank the float bowl full of gas before it will start, depending on how your float bowl vents. An electric fuel pump or an outboard primer bulb fix this.
Is the shunt from the starter motor to the coil hooked up - this is a wire from the + terminal on the coil to a terminal on your starter motor?
 
Check the resistance on your coil, if you're not running a ballast resistor should be about 3 ohms. Unhook the wire from coil to distributor then measure across the + and - terminals. If you're running a resistor should be around 1 ohm. If you run one of these with no resistor you will rapidly fry your points.
I would be suspicious of your plug leads - your first misfire issue
glitch in the matrix here, can't be old age
The way these old motors run properly set up points ignition works fine, at the revs these things pull there's plenty of dwell time to build a decent spark. What causes issues with an old motor is when the distributor shaft bearing wears giving an unreliable gap - this is where Pertronix wins - or where they're an oil burner which may need hotter plugs.
 
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Have you put your timing at 7* and checked vacuum at idle when cold and hot?

If at sea level, I don't recommend exceeding 10* of base timing, pinging can begin if you aren't aware and depending on your tune. As you go up in elevation you can add some additional. Putting timing to 7* ensures you aren't adding timing to hide a vacuum leak, which is very very common.

You never touched on what carburetor and whether it was setup correctly? Hesitation usually is vacuum related OR an issue during fuel movement/lackthereof inside carb, so which carb you have helps.

Also. Stop using AI, download the FSM from one of the MANY folks offering for free and go STEP BY STEP on the engine tune-up. You've done most which is good so far.
 
So alot of good comments & suggestions.

Took her out for a solid run down the highway. I had her at 100 kph for more than a hour and there were no issues. Of course I was bouncing around with those leaf springs. There was no hesitation / misfiring. There are minor on-going issues...but that is always the case.

I think when I pulled out the points & condenser and then re-assembled them, that must have done the trick. Must have been a connection issue.

I think I will still change the condenser, and then re-adjust the dwell angle. Currently its at 39 degrees, but will try to adjust it to at least 40 degrees. But this is no longer a priority.

In conclusion, I think my issue was the external ballast and ignition coil. Both I replaced and the rest was just fine tuning. Thank you everyone for your help & support.
 
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