# Distributor Rotor Head is Loose



## Sundermeyer (Sep 8, 2014)

Hello:

1987 Sentra (First Run) with a D4083-03D (22100-36A01) distributor. (HITACHI)

While performing basic maintenance on the ignition system, I noticed that the Rotor Head was sitting at an angle instead of level. The contact side was a millimeter or two lower than the opposite side and when I removed the head, I could see that the inner diameter of the head was larger than that of the shaft it sits on. I ordered the correct replacement part for the car, 22157-27M02, but it has the exact same dimensions as the old one.

From everything that I can gather online, it would appear that the original part for the car was of a different style and was replaced by a universal fitting one. The problem then is that I get reduced spark performance from the rotor not passing by the contacts in the cap correctly. The only thing I can think of doing to correct this is to make a custom sleeve to fit onto the shaft and in the new rotor head. I have put a temporary piece in it and it helps but until I can get a stronger metal in there, I will constantly be adjusting the alignment.

Has anyone else run into this issue and how was it resolved?


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## Car guy (Mar 31, 2016)

Did you mean D4P83? 

Nissan had two different distributors during this model year whereby one had a shorter length rotor and (accompanying) different cap with longer carbon brushes (the other dizzy had normal length rotor with shorter carbon brushes). Both rotors have the same width of the rotor edge and both rotors sit the same height at roughly 1 5.5/16". May be a "set mismatch." Is the dizzy the original on the car? Also, is the rotor securing bolt the original, with the small washer under the bolt head?


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## smj999smj (Jan 1, 2006)

There shouldn't be any movement of the rotor on the shaft because the bolt secures the rotor to the shaft and keeps it from moving. This is the case on both the Hitachi and Mitsubishi distributors.


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## Sundermeyer (Sep 8, 2014)

Car guy said:


> Did you mean D4P83?


Yep. Try as I might and still put down typos.
D4P83-03D
22100-36A01



Car guy said:


> Nissan had two different distributors during this model year whereby one had a shorter length rotor and (accompanying) different cap with longer carbon brushes (the other dizzy had normal length rotor with shorter carbon brushes). Both rotors have the same width of the rotor edge and both rotors sit the same height at roughly 1 5.5/16". May be a "set mismatch." Is the dizzy the original on the car? Also, is the rotor securing bolt the original, with the small washer under the bolt head?


As far as I know, this is the original distributor on the engine.

I have the shop manual and it describes which vehicles had the Mitsubishi vs the Hitachi unit but mine is supposed to have the Hitachi that it does. I've run into other 1st run issues with this car and suspected that it might be the case with this one but can't find anything to support that idea other than a parts diagram on NissanPartsDeal.com but the rotor part number points to the design that I currently have and not what is shown in the diagram.

Part of the issue on the forum is that since I have had so few posting, it hasn't allowed me to post pictures and links yet. Hopefully soon I can do that.

If it will show the link, here is the distributor that is on my engine. You can see how the rotor end has a narrow portion on the shaft. The rotor sits down on it completely, but when you tighten it up, because of the differences in the shaft size, the head leans in at the top and out at the bottom causing the contact end of the rotor to be ,lower by a little more than a millimeter, on the contact end.

www.jcwhitney.com/p3039753/sku-578912.jcwx

The bolt that comes with the new rotor doesn't fit the distributor so I have to reuse the original one. It is a star type head with a washer and small threads.

(Never heard "dizzy" until researching this on the internet, no one I know calls it that. But I understand the reference.)


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## Sundermeyer (Sep 8, 2014)

smj999smj said:


> There shouldn't be any movement of the rotor on the shaft because the bolt secures the rotor to the shaft and keeps it from moving. This is the case on both the Hitachi and Mitsubishi distributors.


Sorry for the confusion, the rotor fits loosely on the shaft before you put the bolt in. It has a lot of slop to it because the rotor has a bigger hole in it than the shaft it goes onto.

The bolt does keep the rotor on tight but that is not the issue. The issue is that the way that the rotor sits on the distributor when tightened up is not correct. It leans over because the shaft is narrower at the top, where the bolt is at, than at the bottom.

This page shows what the shaft looks like.

www.jcwhitney.com/p3039753/sku-578912.jcwx


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## Car guy (Mar 31, 2016)

Good pic. Yes, can see the superceded 27M02 issue now.

I took a pic of the second run rotor shaft (for which the 27M02 works), but can't seem to "attach" the pic here. This rotor shaft is straight. For the 36A02 dizzy. Maybe you can pull the shaft from a 36A02 at an area junkyard and install it on your 36A01 (and thereby use your 27M02). 

Noticed the metal plate is different on the 36A01 also, and with no rubber seals. The 36A02 and others had rubber grommets with the plate.

If you ever remove the slit plate (under the metal plate), let me know what the optical module part # underneath is (RSB-03, -06, or -07).


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## Car guy (Mar 31, 2016)

I temporarily placed a pic of the correct rotor shaft in my Gallery, for you. '87 E16S is gallery name.


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## Sundermeyer (Sep 8, 2014)

Car guy said:


> Good pic. Yes, can see the superceded 27M02 issue now.
> 
> I took a pic of the second run rotor shaft (for which the 27M02 works), but can't seem to "attach" the pic here. This rotor shaft is straight. For the 36A02 dizzy. Maybe you can pull the shaft from a 36A02 at an area junkyard and install it on your 36A01 (and thereby use your 27M02).
> 
> ...


Thanks for the picture, I have seen that same style while searching for answers as well. I think the easiest thing to do is to make an adapter sleeve to make the rotor fit properly but I will get to that when it gets warm enough outside to work on it.

On the parts diagrams I have seen, there is a single seal but it is no longer available. I could make one if it is really needed.

https://www.nissanpartsdeal.com/diagrams/large/B12/221_G01.png

Thanks for the assistance!


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## Car guy (Mar 31, 2016)

<Thanks for the assistance! >

You're welcome. Glad to see this car still "out there."

The seal in the diagram (you posted) keeps dust and moisture out of the teeny 360 1' (and 4 180') slits in the optical plate (and dirt and moisture out of the dist cap - for the brushes and rotor edge). On the 36A02 and other dizzies, they also had 2 grommets (in addition to the circular seal).


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## Sundermeyer (Sep 8, 2014)

I went back through the Shop Manual for the car and found some things that I had missed, some things that I got wrong, and also some more mysteries.

What was mentioned about the shorter distributor is apparent in the manual but so is the two different shaft styles. In any case, the book doesn't go into which models the two different shaft types belong to. The difference in them besides the shaft is that the electronic wave converter in them behave differently from each other as mine, the older style, has less LED sensors than the later style does.

Also, I was wrong about the model for my car. According to the manual, the distributor should be a D4P83-03E and not the D4P83-03D that is has. However, from some new information that has come to light, this car was produced January 1986 and I found that the correct Rotor Head is from an early 1986 model.

So, just today I installed the 1986 version of the rotor: ECH EP768 (https://www.napaonline.com/en/p/ECHEP768) and it works perfectly. It fits snugly on the shaft, the screw is the right size, and most importantly the rotor sits level. The car runs great on startup and I will have to run it around a bit yet to see if I notice anything different.


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## Car guy (Mar 31, 2016)

<the Shop Manual for the car>

What does the back of the SM show as the Publication # in the lower right corner?
What does it show the Edition to be?
And the Printing date to be?

<The difference in them besides the shaft is that the electronic wave converter in them behave differently from each other as mine, the older style, has less LED sensors than the later style does.>

There were RSB-03, RSB-06 and RSB-07 optical modules? Some had 3 diode pairings and some had just 2. 

Congrats on finding the correct rotor. It looks similar to (or the same as) what went on the 22100-27M05 dizzies. 

Thanks for the update.


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## Sundermeyer (Sep 8, 2014)

Car guy said:


> <the Shop Manual for the car>
> 
> What does the back of the SM show as the Publication # in the lower right corner?
> What does it show the Edition to be?
> And the Printing date to be?


I bought the manual on eBay and so it was just a random thing about getting this particular version of the manual.

Edition: January 1986
Printing: January 1986 (01)
Publication No. SM7E-0B12U0

Printed in Japan


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## Car guy (Mar 31, 2016)

Okay, great; that was THE manual for the '87 year (all 3 engines i, S, and CD).


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