Distributor pick up coil caps/seals cracking

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This past weekend after pulling the distributor from my 1FZFE (325,000 miles) to replace the O-ring I noticed that the plastic seals or caps for the G1 and G2 pick up coils were cracked and was able to lift one of them up revealing the coil underneath. At first I was just going to seal them up but noticed a bit of play in the vertical axis of the shaft and a very faint noise when holding the dizzy bracket to directly to/on my ear while turning the shaft (rough or dry bearing), so decided to install a spare 97 model dizzy I had on the shelf which only has 1/3 the miles on it compared to my original distributor. The lower mile dizzy had no noise or play in the shaft. Attached a few pics.

First shows the crud on the dizzy shaft. This tells me there is another reason to pull the dizzy as a PM, to clean out the shaft housing when replacing the O-ring. Those two open slits provide lube (splashed oil) to the shaft bushing. Second shows setting the air gap on the pick up of the replacement dizzy. I used .276mm for the air gap as it was about where the original pick up gaps were set at. The FSM says .2 to .4mm is good, but I don't understand why the FSM says to replace the dizzy housing if the air gaps are outside that range, the position/air gap of each pick-up is adjustable?? Last photo is the cracked cap or seal of a pick up, haven't decide yet what I may use to reseal/repair that. Just something to check next time you have your distributor out IMHO.





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Don't have pics of this but I cleaned the replacement distributor using aerosol electronics cleaner for the rubber and plastic bits including inside the shaft housing, then some Kroil for the bushing near the pinion gear (I avoid using carb cleaner around rubber seals and plastics as that can cause damage IME but did use it to clean the exterior of the housing, FWIW). After completely flushing out the shaft housing via the two slits to remove the old varnish and crud (another PM item IMO) I installed a new Viton O-ring. Just before stuffing the distributor into the head I poured engine oil (Mobil 1) into those slits to provide lube for the shaft bushing.
 
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blunderbuss

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just took off my distributor and found oil inside the cap. My truck is running fine but I'm replacing the front main seal and oil cover pump cover gasket so I figured Id do this while I'm in there. Besides the o-ring on the shaft is there any other o-ring to replace? In the schematic I have it looks like a sealed unit...
 
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There is a "packing, dust proof " around the top of the distributor housing that helps seal around the edge of the distributor cap. There also should be a shaft seal (hidden) at the base of the housing underneath the reluctor ring and behind the bearing, but that seal is not easily replaceable.

One reason not to use strong carb cleaner when cleaning out the shaft housing is that you might damage that seal IMO, hence the reason I use electronics cleaner which is easier on rubber.

Do you have photos showing the backside and inside of the distributor (before cleaning)?
 
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I cake the outer seal of the dist. cap with dialetric grease and then slap it on. Some extra protection. Hasn't hurt anyway...
 

blunderbuss

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I ended up wiping it clean with a rag, replacing the rotor and o-ring, and putting it together. Truck started and is running fine... It looks like the dust proof gasket is under the connector on the top side of the distributor. I found a part number for it but it doesn't appear to be replaceable, am I missing something? I didn't want to pull on the connector too much.
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Hard to tell where the oil is coming from, either blown in from one of the breather holes or leaking past the shaft seal and bearing?? You could use some electronics cleaner and spray the distributor clean, then watch to see if the oil leak continues. As mentioned above I also use dielectric grease on the gasket and O-ring and the seal inside harness connector (when new and/or for pm), seems to keep the rubber soft longer. FWIW. The dust proof packing/gasket is a separate part. Here's a photo:


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SmokingRocks

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Reviving an old thread, I'm doing a rebuild on a friends engine and when I took his distributor off both of the dust seals on the pickup coils disintegrated. Is there any solution or way to fix this other than replacing the entire distributor?

dizzy10.jpg
 
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The wires for electric motors with exposed windings are often coated with a specific type of insulating red varnish, one common brand is Spray-on EL-601.

I've used this product.to coat the windings of an alternator where the factory insulating varnish was cracking from age/heat/oil exposure.


One way to go about it would be to very carefully clean off the area around the coils first using Electronics cleaner (I would start with Q-tips).

Whatever you do, do not use Acetone, Throttle Body cleaner, or brake cleaner on the distributor, they are too harsh. If anyone used those in the past on the internal components of the distributor to clean off the oil that could be why the caps fell off. Those solvents can also cause old rubber seals (for the shaft seal and bearing) to deteriorate.

There's also a clear insulating varnish, same company:


Warning: the insulating varnish itself has some strong solvents in it so it should only be used on metal. Be careful not to get it on plastic, vinyl, or rubber components.

One way to apply it might be to use a small brush and dab the varnish on the coils.

FWIW
 
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And to add to ^. *IF* the pickup coil(s) fail the engine will NOT start, the ECU needs the signals to fire the coil. So, consider the risk of a poor repair failing when you are somewhere remote.

cheers,
george.
 

cruiserdan

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Unfortunately the distributor housing is discontinued
 
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If the OP still had the small covers to the coils he could glue them back on.
I did this to the distributor on my 96 FZJ80 ?? 8-10 years ago. Still running.

Or, find a used dizzy from the Classifieds

FWIW
 
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I rebuilt the dizzy on my 97, replacing the inner seal and the bearing. I have about 8k miles on it so far, no leaks or other nonsense. The old seal was very hard, but the bearing was still very smooth, but while I was in there replaced it anyway. On the pickups, try some liquid electrical tape. I did buy a new distributor about 6 months ago from UAE, it was not cheap.
 

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