If you do take it apart be sure to check and if necessary regap the reluctor.
Thank you for mentioning this David. I probably would have overlooked it.
Do you have the specs on this? I assume this is the reluctor gap you are talking about?
I found these specs in the manual on page 28, for 0.25mm with a feeler gauge if I'm reading this correctly.
I tried to find this info in the Volo book (because its usually much easier to interpret but i didn't see it in there)
IMG_9053.jpgScreen Shot 2019f.jpg (sorry these screen grabs of the shop book are so tiny, not sure why. I think this forum doesn't like PNG files. I made one a JPG and that looks good now)
Go to M:01:01 for a nice exploded view of the distributor. The specs are on M:01:04 and the gap is called out as 0.25mm and be sure to use a brass feeler gauge because of the magnetic field. If the coil is bad it will be intermittent and a room temp it will measure good so you can't properly test it. As I said, the typical failure mode is the car will start and run fine but after about 20 minutes it will die and not restart till it cools. This is different from the hot restart problem (loss of rest pressure) because a bad accumulator (or whatever causes your loss of rest pressure) will NOT kill a running motor. It DOES mimic the bad pick-up coil because it won't restart til it cools off. The big question again, does the car stop running or is it just hard to restart hot? It is a lot of work to do the distributor and if the coil is not bad you won't be fixing the problem. I would get the timing set up correctly though. Follow the timing procedure on M:01:02 and I would add disconnect the vacuum from the distributor and plug it. While you have the timing light set up check the vacuum and mechanical advance. The specs are also there for that. On one car that had a loping idle the gap was not consistent and the owner tried all kinds of things to fix it. Nothing worked till we did the distributor so that gap is important. On a post way back one owner complained whenever he took his car out for a ride it always died at about the same point away from his house, about a 20 minute ride. It was his impulse coil. A bad pick-up coil aka impulse coil, is not as common as it used to be. Not holding rest pressure is a lot more common. There is one definitive way to rule out a bad coil. When it won't restart hot, do the plug swap. If it starts right up, the coil is good.
Not holding rest pressure is a lot more common. There is one definitive way to rule out a bad coil. When it won't restart hot, do the plug swap. If it starts right up, the coil is good.
Thanks for the tip about the brass gauge. You are correct, this is a lot of work but mentally it will make me feel better to know i have hit these things. I have a few "while I'm in there" VOD stuff to hit too.
To answer your question. My symptoms are as follows: The car starts cold fine, runs and does not die at all while running. When up at temperature and i shut down, it will not restart till the car cools down.
My first efforts we're changing the fuel accumulator, rebuilt fuel distributor, inserting an inline check valve at the pump, spark plug wires, new fuel pump and clean tank, PPR o-ring. The car had holding pressure and no external fuel leaks.
When the car was hot, the plug swap would not work to start it. And i could tell it was dumping fuel into the system by how it smelled, i even pulled the cold start injector to verify. Now I'm focusing on spark and timing.
This week I changed the spark plugs to NGKs and gapped them correctly (PO had some weird 4 pronged plugs in there), changed the fuel filter, a new ballast resistor, a new upgraded coil, all new fuel injectors, and put in the Hervey upgraded ground wires.
Last items on the list are this pick-up coil, new battery, then check fuel pressures are in spec, engine timing and finish off with dwell mixture.
I have a new fuse block to install but will get to that after i get the engine back together and test it. Im basically trying to bullet proof this cars ignition/fuel system.
I understand i can't tell anything from a room temp coil but can i put it in my oven to get it up around 190 and then take measurements on a DMM?
Still does not sound like a bad impulse coil. I would go back to the stock ignition coil. A lot of owners had problems and they went away when they went back to the stock coil.
I think kings1527 asked for this image. I'm in the middle of a refurb on the distributor and thought this image may be helpful to some people looking to get into the little bits. DSC06029.jpg
I should also mention this.
There is a 1 mm long rod that sits in a groove in the distributor to hold a part from spinning. It's so small you might not even notice it. BUT its crucial and if you loose it you are screwed. you can see it as soon as you take off the first snap ring. It sits against the center. Good luck with your rebuilds.
Originally Posted by David T
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