1986 3.2L Carrera Distributor Woes
11-26-2011, 12:07 AM
#1
Instructor
Thread Starter
1986 3.2L Carrera Distributor Woes
Folks,
I went to change the Ignition Distributor Cap & Rotor on my bone stock 1986 3.2L Carrera Coupe today and got a surprise - a portion of the Rotor shaft came off with it! I didn't have access to a decent camera so, sadly, I have no photos but I will try to do my best to describe things.
The Rotor must have 'frozen' to the Upper-Outer shaft w/notch that the Rotor press-fits onto. This Upper-Outer shaft fits over the Lower-Inner shaft that actually descends into the engine and has the distributor gear attached to it. After a thorough search of the engine compartment for everything that 'flew out', I think I have all the pieces. Here's a list of what I found. Keep in mind that the 'nomenclature' is mine - I don't know the real name of the parts because I can't find a diagram of the distributor with sufficient detail. It's also in a 'Top-Down' order that represents what I have after reassembling things:
1) Rotor
2) Plastic Dust Cover
3) 1/4" Thick Fiber/Felt Circular Pad
4) Circular Wire Spring Clip to secure Upper-Outer shaft to Lower-Inner shaft
5) Thin Small Washer (underneath Wire Spring Clip above)
6) Upper-Outer Distributor Shaft (installed over Lower-Inner shaft)
7) Thin Larger Washer (at bottom of Lower-Inner shaft)
8) Two small Coil Springs
The two small Coil Springs seem to be part of an ignition advance (?) system. Each one appears to attach to one of two ceramic coated 'horns' on a plate affixed to the bottom of the Upper-Outer shaft for their INNER (as in towards the center of the shaft) attachment points, with their OUTER attachment points being one of two ceramic coated 'horns' where each horn is on what appears to be a moveable 'fly-weight' of sorts (two total). I truly hope the above description has made some kind of sense.
After reassembly, the car runs fine but I sure would like a check of my 'parts list' and assembly order. Am I missing any clips/washers/springs etc.?!?!
The BAD news is that three of the four ceramic coated horns for the Coil Spring attachment points have had the ceramic crack and break away (due to age and me pulling the Upper-Outer shaft off while the springs were attached I suppose).
The ceramic looks just like the dull-red material the Cap and Rotor are constructed of and appear to exist only to help 'trap' or otherwise keep the springs in place. When viewed from the side they have a shape resembling an empty spool of thread held vertically (along its axis). Luckily, each of them has an internal, round metal shaft that the original ceramic coating was molded/formed over.
I came up with a 'fix' using one very TINY, lightweight and tight-fitting E-Clip for one of the damaged INNER horns (on the base of the Upper-Outer shaft). I'm pretty confident that's good for now.
The inner metal shafts on each of the OUTER 'fly-weight' horns are different and I ended up using some quality 'heat shrink' tubing of small diameter to form a 'cap' on them to insure that the springs do not dislodge. This seems to be sufficient but I'm not sure I really like it.
It seems to me that the only 'forces' on the springs and their mounts are centrifugal rotation (outward), rotation acceleration (rearward) and rotation deceleration (forward). The force I'm thinking I would be worried about would be an 'upward' one, causing a spring to move Up and Off of its vertical attachment shaft, but I don't see that force being present after looking at how the distributor works.
I think what I REALLY need is a new distributor. Thoughts? I did a quick search but only came up with NLA for the '84-'89 Carrera. Are rebuilt ones around? I'm worried about ordering a 'used' one from one of the salvage operations because it could only show up with the Ceramic Coated horns damaged or missing their coating entirely (like three of my four are now).
While I await your input, there are two things I'd recommend - the next time you install a new rotor make SURE your old one is NOT frozen to that Upper-Outer shaft! Using something to hold that Upper-Outer shaft in place during the Rotor removal process could also be a good idea. I'd also recommend that you find a suitable, non-volatile lubricant and smear a small dab of it around the Rotor / Upper-Outer shaft mounting interface so you can be assured the Rotor will come off easily the next time you change things out. What kind of 'lube'? I don't know but I hope someone can suggest something appropriate.
Best Regards,
Barry
(Who now KNOWS that a few photos are worth MUCH more than 1,000 words!)
I went to change the Ignition Distributor Cap & Rotor on my bone stock 1986 3.2L Carrera Coupe today and got a surprise - a portion of the Rotor shaft came off with it! I didn't have access to a decent camera so, sadly, I have no photos but I will try to do my best to describe things.
The Rotor must have 'frozen' to the Upper-Outer shaft w/notch that the Rotor press-fits onto. This Upper-Outer shaft fits over the Lower-Inner shaft that actually descends into the engine and has the distributor gear attached to it. After a thorough search of the engine compartment for everything that 'flew out', I think I have all the pieces. Here's a list of what I found. Keep in mind that the 'nomenclature' is mine - I don't know the real name of the parts because I can't find a diagram of the distributor with sufficient detail. It's also in a 'Top-Down' order that represents what I have after reassembling things:
1) Rotor
2) Plastic Dust Cover
3) 1/4" Thick Fiber/Felt Circular Pad
4) Circular Wire Spring Clip to secure Upper-Outer shaft to Lower-Inner shaft
5) Thin Small Washer (underneath Wire Spring Clip above)
6) Upper-Outer Distributor Shaft (installed over Lower-Inner shaft)
7) Thin Larger Washer (at bottom of Lower-Inner shaft)
8) Two small Coil Springs
The two small Coil Springs seem to be part of an ignition advance (?) system. Each one appears to attach to one of two ceramic coated 'horns' on a plate affixed to the bottom of the Upper-Outer shaft for their INNER (as in towards the center of the shaft) attachment points, with their OUTER attachment points being one of two ceramic coated 'horns' where each horn is on what appears to be a moveable 'fly-weight' of sorts (two total). I truly hope the above description has made some kind of sense.
After reassembly, the car runs fine but I sure would like a check of my 'parts list' and assembly order. Am I missing any clips/washers/springs etc.?!?!
The BAD news is that three of the four ceramic coated horns for the Coil Spring attachment points have had the ceramic crack and break away (due to age and me pulling the Upper-Outer shaft off while the springs were attached I suppose).
The ceramic looks just like the dull-red material the Cap and Rotor are constructed of and appear to exist only to help 'trap' or otherwise keep the springs in place. When viewed from the side they have a shape resembling an empty spool of thread held vertically (along its axis). Luckily, each of them has an internal, round metal shaft that the original ceramic coating was molded/formed over.
I came up with a 'fix' using one very TINY, lightweight and tight-fitting E-Clip for one of the damaged INNER horns (on the base of the Upper-Outer shaft). I'm pretty confident that's good for now.
The inner metal shafts on each of the OUTER 'fly-weight' horns are different and I ended up using some quality 'heat shrink' tubing of small diameter to form a 'cap' on them to insure that the springs do not dislodge. This seems to be sufficient but I'm not sure I really like it.
It seems to me that the only 'forces' on the springs and their mounts are centrifugal rotation (outward), rotation acceleration (rearward) and rotation deceleration (forward). The force I'm thinking I would be worried about would be an 'upward' one, causing a spring to move Up and Off of its vertical attachment shaft, but I don't see that force being present after looking at how the distributor works.
I think what I REALLY need is a new distributor. Thoughts? I did a quick search but only came up with NLA for the '84-'89 Carrera. Are rebuilt ones around? I'm worried about ordering a 'used' one from one of the salvage operations because it could only show up with the Ceramic Coated horns damaged or missing their coating entirely (like three of my four are now).
While I await your input, there are two things I'd recommend - the next time you install a new rotor make SURE your old one is NOT frozen to that Upper-Outer shaft! Using something to hold that Upper-Outer shaft in place during the Rotor removal process could also be a good idea. I'd also recommend that you find a suitable, non-volatile lubricant and smear a small dab of it around the Rotor / Upper-Outer shaft mounting interface so you can be assured the Rotor will come off easily the next time you change things out. What kind of 'lube'? I don't know but I hope someone can suggest something appropriate.
Best Regards,
Barry
(Who now KNOWS that a few photos are worth MUCH more than 1,000 words!)
11-26-2011, 05:43 PM
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This is a reassembly thread with some pictures, might help?
http://forums.pelicanparts.com/porsc...eassembly.html
http://forums.pelicanparts.com/porsc...eassembly.html
11-27-2011, 07:30 PM
#5
Instructor
Thread Starter
This is a reassembly thread with some pictures, might help?
http://forums.pelicanparts.com/porsc...eassembly.html
http://forums.pelicanparts.com/porsc...eassembly.html
Barry
12-08-2011, 03:59 AM
#6
Instructor
Thread Starter
Folks,
AH HA - an update w/INTERESTING results! While I STILL have NOT been able to find a definitive diagram of how this 1986 3.2L Carrera distributor goes together, DublinOh's link above helped me feel MUCH better about how I assembled things after it unexpectedly came apart during a 'simple' Cap & Rotor change! The link provides a good intro to the subject and should be read to add to your 'knowledge base'. Just be aware that it needs to be viewed as a GREAT article on the distributor and not as a 'step-by-step in part order' tutorial. With that said, the article was EXTREMELY helpful in determining what I had (parts wise) and where it should probably go and my hat is off to both the writer of the article (88-diamondblue on Pelican's forum) and to DublinOh for providing the link. It lowered my 'panic' level by several points! I definitely owe BOTH you guys!
Now the INTERESTING part! Once again, the terms are mine as I do not have a diagram that gives the appropriate names for the parts. After digesting the info from the link, I disassembled/reassembled things a few times just to make myself feel better about what I had. Part of this process involved removing the spring-loaded 'fly-weights', cleaning and delicately lubing their 'pivot shafts' and reinstalling them. As I currently understand it, these 'fly-weights' allow the Rotor to slightly change its position relative to the gear driven central shaft and the Distributor Cap contact points at higher RPMs. The 'pivot shafts' were pretty well coated with years of fine particle build-up and, while the 'fly-weights' would move, they didn't do so in a smooth and free manner. After cleaning they certainly DO now!
While the DME Control Unit determines the actual ignition timing, these 'fly-weights' appear to play an important role in insuring that the Rotor is close enough to the Distributor Cap contact points to relay a good, strong spark impulse for each cylinder regardless of the change in timing dictated by the DME. I'm sure that there are others that can provide a more accurate description of this cycle but this is the best I can do!
And NOW the PAYOFF! This car (bought used in 2002) has ALWAYS had a noticeable power surge under hard acceleration at about 4800 - 5000 RPM. Not being a 911 engine 'guru', I attributed this to a change in the DME timing map around that RPM setting. There was a 'notch' (so to speak) at that point where the power went from 'Oh Yeah!' to 'HOLY SH_T!'. Well, this is no longer the case!
Now, under hard acceleration up to 6000+ RPM, the engine pulls in an extremely SMOOTH, AGGRESSIVE and CONSISTENT manner. No 'notch' - just a progressively stronger pull all the way from mid-range RPM to as far as you want to push it. It's got me giggling as it's an entirely NEW experience for me with this car. I've got to ask, could the simple job of 'freeing up' these 'fly-weights' (all I did was clean them and lube their 'pivot shafts') have such a noticeable impact?
Barry
(Who feels like he has a NEW '86 Carrera!)
AH HA - an update w/INTERESTING results! While I STILL have NOT been able to find a definitive diagram of how this 1986 3.2L Carrera distributor goes together, DublinOh's link above helped me feel MUCH better about how I assembled things after it unexpectedly came apart during a 'simple' Cap & Rotor change! The link provides a good intro to the subject and should be read to add to your 'knowledge base'. Just be aware that it needs to be viewed as a GREAT article on the distributor and not as a 'step-by-step in part order' tutorial. With that said, the article was EXTREMELY helpful in determining what I had (parts wise) and where it should probably go and my hat is off to both the writer of the article (88-diamondblue on Pelican's forum) and to DublinOh for providing the link. It lowered my 'panic' level by several points! I definitely owe BOTH you guys!
Now the INTERESTING part! Once again, the terms are mine as I do not have a diagram that gives the appropriate names for the parts. After digesting the info from the link, I disassembled/reassembled things a few times just to make myself feel better about what I had. Part of this process involved removing the spring-loaded 'fly-weights', cleaning and delicately lubing their 'pivot shafts' and reinstalling them. As I currently understand it, these 'fly-weights' allow the Rotor to slightly change its position relative to the gear driven central shaft and the Distributor Cap contact points at higher RPMs. The 'pivot shafts' were pretty well coated with years of fine particle build-up and, while the 'fly-weights' would move, they didn't do so in a smooth and free manner. After cleaning they certainly DO now!
While the DME Control Unit determines the actual ignition timing, these 'fly-weights' appear to play an important role in insuring that the Rotor is close enough to the Distributor Cap contact points to relay a good, strong spark impulse for each cylinder regardless of the change in timing dictated by the DME. I'm sure that there are others that can provide a more accurate description of this cycle but this is the best I can do!
And NOW the PAYOFF! This car (bought used in 2002) has ALWAYS had a noticeable power surge under hard acceleration at about 4800 - 5000 RPM. Not being a 911 engine 'guru', I attributed this to a change in the DME timing map around that RPM setting. There was a 'notch' (so to speak) at that point where the power went from 'Oh Yeah!' to 'HOLY SH_T!'. Well, this is no longer the case!
Now, under hard acceleration up to 6000+ RPM, the engine pulls in an extremely SMOOTH, AGGRESSIVE and CONSISTENT manner. No 'notch' - just a progressively stronger pull all the way from mid-range RPM to as far as you want to push it. It's got me giggling as it's an entirely NEW experience for me with this car. I've got to ask, could the simple job of 'freeing up' these 'fly-weights' (all I did was clean them and lube their 'pivot shafts') have such a noticeable impact?
Barry
(Who feels like he has a NEW '86 Carrera!)
