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Distributor plug lead order and rotor direction help needed

Discussion in '365 GT4 2+2/400/412' started by sebackman, Jun 6, 2021.

  1. sebackman

    sebackman Karting

    May 19, 2010
    109
    Europe
    Hi all,


    I have a 400i 1980. And just took my distributor cap and rotor off to swap in a new ones and noticed that the leads may not have been in the correct order on the distributor cap.


    The new dizzy cap has no connections markings.


    The old cap says 1-12-5-8-3-10-6-7-2-11-4-9 in clockwise direction which seems like the correct true fire order.


    The owners manual says the same,1-12-5-8-3-10-6-7-2-11-4-9, and shows a picture of the (maybe) cable order on the dizzy clockwise from 1.


    I seem to remember that the order on the distributor different due to the distributor design which changes the order/angle meaning that the spark plug leads should be in a different order on the distributor cap compared to true fire order. Is that correct?


    If so, is the correct order then 1-7-5-11-3-9-6-12-2-8-4-10 clockwise from above from 1 on the distributor cap?


    Please confirm if this is correct


    I also noted that the rotor can be mounted in two directions. Is there a way to see what is the right direction? I know how it was mounted when I took it out but don’t know if that is the correct way.

    She did run bad on the right bank hence the decision to put in new cap and rotor.

    Thank you

    //Rob
     
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  3. markcF355

    markcF355 F1 Rookie
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    #2 markcF355, Jun 6, 2021
    Last edited: Jun 6, 2021
    Rob,

    You rotate the engine to cyl 1 TDC on compression. At that point the rotor should line up with the red mark on the distributor. There should be an index pin to align the cap on the distributor. I'm not sure why you say "in two directions".

    Once that happens, you know what is #1 position on the cap.

    Then follow this:
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    Hope this helps.

    Some caps come with numbers on them that screw up the left bank. Don't know why.
     
  4. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
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    Jan 11, 2001
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    Correct -- the order of the wires going around the dist cap does not match the actual order that the cylinders fire (due to the double-ended rotor and every other wire being served by the same rotor end). Mark's diagram is correct for the order of the wires going around the dist cap. This is a good cross-section drawing previously posted by Peter Moser:
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  5. sebackman

    sebackman Karting

    May 19, 2010
    109
    Europe
    Thank you for the replies.

    Look like the leads were in the right order. Good news.

    Agree, the cap can only be mounted one way and the index pin is there.

    But for the rotor, the shaft is completely round and the threaded hole goes trough the shaft which means that the rotor can be mounted two ways by rotating it 180 degrees. I believe it was mounted in the correct way, but wanted to check as all is apart.

    The car is on the ground and it seem impossible to find a way to rotate the engine from above. Is it easy to move the crank from below?

    How do I find compression phase without taking the valve covers off? Is there an easy way?

    TDC I can find with a rod in the spark plug hole as they are all out for cleaning.

    I read the post from Peter. I did not really get the part regarding checking if the advance mechanism is free. How do I do that? Can I move the toothed wheel to see if it works?

    On the oiling. What kind of oil should be used? Maybe ordinary engine oil is fine. If the timing mechanism is free should it be oiled too?


    Kind regards
    //Rob
     
  6. raemin

    raemin Formula Junior

    Jan 16, 2007
    882
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    R. Emin
    The various alignments are not described in the ignition section (chapter D) of the Workshop Manual , you have to look at chapter B (B-61). The system is not as idiot-proof as what I am used to with breaker point distributors, so once the distributor is removed you are likely to loose the timing settings, but the manual just explains clearly how to properly re-install everything. In any case static adjustment is a really crude way to tune the timing, I would advise you to make a final check with a timing light (i.e you will have to lift the car in order to access the flying wheel).

    Not sure you can check the advance mechanism (pivots and centrifugal weights) while the distributor is in the car, so here again most simple approach is to check with a timing light that the advance works (when the engine runs). As long as you passed the previous test, I would not remove the distributor ans just add regular engine oil to the "Wick".

    This being said I did exactly the opposite as I wanted to justify the horrendous cost of my distributor tester, so everything removed from the engine just to find out that the distributor was still properly working.
     
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  8. SouthJersey400i

    SouthJersey400i Formula 3

    Mar 14, 2007
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    Ken Battle
    If advance mechanism is wrong or in doubt you can send it to Dave North. He has test bank and lots of experience setting them up for correct advance. He has an ad in FCA's Prancer. I can provide contact info, also.
    Ken
     
  9. sebackman

    sebackman Karting

    May 19, 2010
    109
    Europe
    Thank you for all the help. This is a great forum.

    I did take a look at the bottom of the distributor and it is rather dirty with some brownish muck on the inside. The mechanism moves freely, ie I can move the rotor a few degrees (probably close to 30) without any force but kind of sticks in one end. Is there a magnet down there or is it just the muck?

    I do run an MSD box as many others, if that matters.

    If I mark the position of the rotor and the distributor casing position, is it possible to remove the distributor housing for cleaning and drop it back in the same position if nothing moves on the engine? I do understand that I need to do a full allignment with a light but need to be able to drive the car to where there is a lift. But will I find the right gear/teeth when dropping it back or is that a ”procedure”.

    Is it easy to open the distributor to clean the internals once out of the car? The bearings feel fine.

    I don´t see any ”Wick”. Where is that supposed to sit? In the rotor or on top of the axle?

    Kind regards
    //Rob
     
  10. markcF355

    markcF355 F1 Rookie
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    I never understood what the "wick" is for.
    You must replace the seal (24) at the bottom of the shaft. The muck comes from crank case steam entering the distributor past this seal.

    Image Unavailable, Please Login

    Although the rotor can go on the shaft either way, pointing it at the red line will be correct when the engine is at compression TDC. The easiest way to find compression TDC is to have someone watching a compression gauge on cylinder one. When the needle starts to move, you're compressing. Stop on the flywheel mark and there you are.
     
  11. sebackman

    sebackman Karting

    May 19, 2010
    109
    Europe
    Great. Does the seal com up with removing the distributor or how do I get to it?

    I also thought about using a compression gauge to find tdc 1. Thank you for confirming that route. I don’t want to open the valve covers if it can be avoided.

    Is it easy to get into the distributor for cleaning? Looks like there are screws at the botton that will give access to the internals. By the few pictures I have seen it looks pretty basic in there. A good clean and a new seal should do the trick. Engine has about 30000km on it. The mechanics should not be worn.

    Thank you
     
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  13. SouthJersey400i

    SouthJersey400i Formula 3

    Mar 14, 2007
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    If you have brown/rust color near bottom you should change the lower bearing. The upper one lasts "forever". You can get replacement at a good bearing shop without using F sources. In Mark's post, I think 24 is the bearing and 5 is the seal.
    Ken
     
  14. raemin

    raemin Formula Junior

    Jan 16, 2007
    882
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    Wick is a sponge like material that is inserted in the inner diameter of the shaft, under the rotor. Sorry or the poor description... It is removable so easily lost. I usually saturate it with oil whenever I open the distributor. The capacity is quite modest, maybe the equivalent of 4 drops of oil.
     
  15. markcF355

    markcF355 F1 Rookie
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  16. sebackman

    sebackman Karting

    May 19, 2010
    109
    Europe
    Great news. Thank you.

    A new seal just arrived from UK and I have the rest of the parts so I will pull the distributor over the weekend or next week.

    Do I need the "wick"? Can I make my own? I can't see one in my distributor. Can it be stuck in an old rotor? I think I have one swapped out many years ago.

    Is the shaft easy to pull (after the distributor is out)? Seal should be fine to get out. Does the boss come up with it? Is the shaft just to pull straight up? Does the lower shaft have to sit in a specific direction going back after changing the seal or can that be compensated with the rotor axle? If direction sensitive are there markings to follow?

    Do you have a picture of the mechanism with the parts showing?

    I have a similar electric cleaner and will try that. Thank you for the tip.

    Thank you for all the help
    //Rob
     
  17. markcF355

    markcF355 F1 Rookie
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    Do I need the "wick"? Can I make my own? I can't see one in my distributor. Can it be stuck in an old rotor? I think I have one swapped out many years ago.
    - I don't know why it's there, so. . .

    Is the shaft easy to pull (after the distributor is out)? Seal should be fine to get out. Does the boss come up with it? Is the shaft just to pull straight up? Does the lower shaft have to sit in a specific direction going back after changing the seal or can that be compensated with the rotor axle? If direction sensitive are there markings to follow?
    - Yes, the lower shaft just pulls out. There isn't an orientation, but you might have to rough-fit the distributor to see if the lower shaft needs to me rotated one tooth. There is a relationship between the gear at the bottom and the spline at the top.

    Do you have a picture of the mechanism with the parts showing?
    - No, I don't. Sorry.

    I have a similar electric cleaner and will try that. Thank you for the tip.
    - I find these better than using thinner or alcohol because they don't leave the chalky residue.

    Good luck.
     
  18. sebackman

    sebackman Karting

    May 19, 2010
    109
    Europe
    Thank you for all support. I have now removed the distributor and cleaned out all old muck.

    I did find the "wick" below the small boss that holds the rotor screw. It was in good order but of course dry as gun powder.

    After takning mine completely apart and understanding how it works I would believe that many older V12 with the same distributor type are crippled by the wights not moving freely. Mine has only covered 32k km's so it has clearly sat too much and maybe that has lead to the drive shaft seal to dry out and leak. But by the way these are made I would not be surprised if it proved to be uncommon.

    It was not very complicated, albeit time consuming and many parts, and it still needs to go back into the car.

    Most stuff was fine, including bearings, but the weights had definitely not moved the last many years. They were completely stuck.

    Now all is good but I need to make a new gasket between the rotor assembly and the distributor case. There was an simple paper gasket that ripped when I opened it. I don't want to use floating gasket down there.

    I have taken many pictures and will do a write-up for others looking to do the same.
     
  19. raemin

    raemin Formula Junior

    Jan 16, 2007
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    TetraPak milk containers do make excellent gaskets... You can also buy sheet of gaskets that are easy to cut with hobby-scissors (small curved blades).

    Once everything is back in the engine do not forget to test the dynamic advance with a timing light a 5000rpm!

    PS: I am on the same boat, the distributor sits on top of my sun tester, but still have to make a booster for the signal of the reluctor pickup.
     
  20. sebackman

    sebackman Karting

    May 19, 2010
    109
    Europe
    Hi raemin,

    I bought gasket paper and used a dividers (??) to cut a new gasket. Worked fine. The distributor is going back in tomorrow.

    All seem to work just fine. I have a few dizzy caps and will dig out the best and the best rotor. I have changed the seal towards the engine and all o-rings. She has only 30k kms so nothing was worn.

    What marking on the flywheel do you use for 5k advance check? I plan to set up the static distibutor to line up a 8 degrees before TDC (AF 08).

    Kind regards
    //Rob
     
  21. raemin

    raemin Formula Junior

    Jan 16, 2007
    882
    Lyon (FR)
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    R. Emin
    I depends on the engine you have, if this is a 400i, you should normally use the 8° mark of the flywheel. From then on you should check with a timing light that this static adjustment is still valid when the engine runs. I'd rather have a bit more than a bit less timing. 8° is quite low, which is good for emissions but lets escape hotter gases to the exhaust (our exhaust ports are thin so may not like it).
     
  22. raemin

    raemin Formula Junior

    Jan 16, 2007
    882
    Lyon (FR)
    Full Name:
    R. Emin
    For 5k, you should use an "auto" timing light which can shift the illumination by whatever advance timing you want.

    If you set it to 24°, it will illuminate the 0°mark of the flywheel whenever the advance reaches 24°+0° = 24°, or 8° mark when the timing reaches 24°+8° = 32°. It will also display the current rpm of your engine, so you can measure the actual advance at various rpms and validate this is more or less compliant with the timing curve stated in the manual.

    You should avoid the cheap lamps as they can be off by 2°. I am using a Innova #5568 timing light, works great. That's the "pro" version ($129), the middle range version is quite capable also.
     

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