Speed and reference sensors. Which is which?
11-12-2002 | 12:40 AM
#1
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Speed and reference sensors. Which is which?
I made a mistake when I decided to replace my bellhousing ground wire...
forgot to label which is the speed and which is the reference sensor (the connectors b/w the intake manifold and firewall). And unfortunately, the wires no longer have the factory labels/stickers on them.
I hooked them up, based on the way they were oriented, started the car and everything was fine.
Does the car start and run fine with the speed and reference connectors mixed up?
What symptoms are there in having these two sensors mixed up?
I'd like to meet the moron that made the connectors identical and share the same connector bracket!
forgot to label which is the speed and which is the reference sensor (the connectors b/w the intake manifold and firewall). And unfortunately, the wires no longer have the factory labels/stickers on them.
I hooked them up, based on the way they were oriented, started the car and everything was fine.
Does the car start and run fine with the speed and reference connectors mixed up?
What symptoms are there in having these two sensors mixed up?
I'd like to meet the moron that made the connectors identical and share the same connector bracket!
11-12-2002 | 09:28 AM
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I will confirm that... the car won't run if you have them wrong. The factory wiring should be tagged as "B" for the speed sensor and "D" for the reference sensor. The Flywheel Sensor Bracket is similarly marked, altho you'd need a dentist mirror to actually see the markings.
Regards, ...Scott
Regards, ...Scott
11-12-2002 | 10:02 AM
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[quote]Originally posted by G951:
<strong>...
I hooked them up, based on the way they were oriented, started the car and everything was fine.
1. Does the car start and run fine with the speed and reference connectors mixed up?
2. What symptoms are there in having these two sensors mixed up?
3. I'd like to meet the moron that made the connectors identical and share the same connector bracket!</strong><hr></blockquote>
1. No
2. Car will crank but will not start, backfire, nasty...
3. They actually use the same sensors (same part numbers) for both... there is a shim in one to avoid hitting the flywheel (ask me how I know
). When you find him, do not let him go until I am done with him.
<strong>...
I hooked them up, based on the way they were oriented, started the car and everything was fine.
1. Does the car start and run fine with the speed and reference connectors mixed up?
2. What symptoms are there in having these two sensors mixed up?
3. I'd like to meet the moron that made the connectors identical and share the same connector bracket!</strong><hr></blockquote>
1. No
2. Car will crank but will not start, backfire, nasty...
3. They actually use the same sensors (same part numbers) for both... there is a shim in one to avoid hitting the flywheel (ask me how I know
). When you find him, do not let him go until I am done with him.
11-12-2002 | 10:18 AM
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[quote]I'd like to meet the moron that made the connectors identical and share the same connector bracket! <hr></blockquote>
I'm still looking for the sunroof guy and the t-stat snap ring guy.
I'm still looking for the sunroof guy and the t-stat snap ring guy.
11-12-2002 | 02:20 PM
#7
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Just a tip from experience. Leave the metal retaining clips (there are two, one per wire)where the sensor wire plugs in off until you get the right sensor plugged into the right connector. It sure is a whole lot easier than physical removing the sensors from the bell housing and reversing them.
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11-12-2002 | 02:28 PM
#8
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[quote]Originally posted by G951:
<strong>
I'd like to meet the moron that made the connectors identical and share the same connector bracket!</strong><hr></blockquote>
You'll like the 'S' models as they have only one sensor. Porsche figured out how to use one for both speed and referance. Think this is true for the 968.
<strong>
I'd like to meet the moron that made the connectors identical and share the same connector bracket!</strong><hr></blockquote>
You'll like the 'S' models as they have only one sensor. Porsche figured out how to use one for both speed and referance. Think this is true for the 968.
11-12-2002 | 02:54 PM
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"3. I'd like to meet the moron that made the connectors identical and share the same connector bracket!"
Yeah, this is the Porsche service-engineering department. The same guy who did the circlip, plastic balljoint cups, etc.
The later cars used only one sensor because they broke a tooth off the ring-gear to indicate a TDC reference.
Yeah, this is the Porsche service-engineering department. The same guy who did the circlip, plastic balljoint cups, etc.
The later cars used only one sensor because they broke a tooth off the ring-gear to indicate a TDC reference.
11-12-2002 | 03:00 PM
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From: NJ
Thanks all!
I'm relieved to hear that I didn't botch things up.
Amazing how the engineers thought that this was actually a reasonable enough design for production. Guess they figured those little wire labels would hold up to years of turbo temps!
Then again, the engineers who designed the clutch make these speed/reference dudes look like Einsteins!
<img src="graemlins/xyxwave.gif" border="0" alt="[bigbye]" />
I'm relieved to hear that I didn't botch things up.
Amazing how the engineers thought that this was actually a reasonable enough design for production. Guess they figured those little wire labels would hold up to years of turbo temps!
Then again, the engineers who designed the clutch make these speed/reference dudes look like Einsteins!
<img src="graemlins/xyxwave.gif" border="0" alt="[bigbye]" />
11-12-2002 | 03:43 PM
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[quote]Originally posted by Danno:
<strong>
The later cars used only one sensor because they broke a tooth off the ring-gear to indicate a TDC reference.</strong><hr></blockquote>
Must make one heck of a racket when the starter comes around and sees that missing tooth!!!
<strong>
The later cars used only one sensor because they broke a tooth off the ring-gear to indicate a TDC reference.</strong><hr></blockquote>
Must make one heck of a racket when the starter comes around and sees that missing tooth!!!
11-12-2002 | 04:15 PM
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[quote]Originally posted by M758:
<strong>I thought the later cars had 3 sensors
</strong><hr></blockquote>
My 83 had two.
The 86 automatic I parted out had the three sensors.
The factory manuals show only one for the 944S models.
<strong>I thought the later cars had 3 sensors
</strong><hr></blockquote>
My 83 had two.
The 86 automatic I parted out had the three sensors.
The factory manuals show only one for the 944S models.
11-12-2002 | 05:41 PM
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[quote]Originally posted by M758:
<strong>I thought the later cars had 3 sensors
DG
BG
OT
I just installed these back in when doing my clutch and found 3 sensors where my 944 NA has only the BG DG sensor.</strong><hr></blockquote>
They do (at least my '87 951 does)... but that third one is really not needed
<strong>I thought the later cars had 3 sensors
DG
BG
OT
I just installed these back in when doing my clutch and found 3 sensors where my 944 NA has only the BG DG sensor.</strong><hr></blockquote>
They do (at least my '87 951 does)... but that third one is really not needed