Pelican Parts
Parts Catalog Accessories Catalog How To Articles Tech Forums
Call Pelican Parts at 888-280-7799
Shopping Cart Cart | Project List | Order Status | Help



Go Back   Pelican Parts Forums > Porsche Forums > Porsche 911 Technical Forum


Reply
 
LinkBack Thread Tools Rate Thread
Author
Thread Post New Thread    Reply
Registered
 
Join Date: Jan 2007
Location: Vancouver,Canada
Posts: 225
speed and reference sensor

Hi everybody according to bentley manual to test the terminal resistance 1 and 2 is 960+- 96 ohm which I within spec, but terminal 1and 3 and 2 and 3 should be > 100000 ohm I cannot get any reading at all, is that means I have to replace both sensor? if I have to replace is that anyway without drop the engine, thanks for you input.

__________________
Steve
Old 05-21-2008, 02:15 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #1 (permalink)
Registered
 
pookie's Avatar
 
Join Date: Dec 2001
Location: Knoxville TN
Posts: 779
I can't attest to the measurement, but it is possible to do both sensors without dropping the engine. It's more of a pain in the butt, however it can be done. The short version

-Jack up the car
-remove driver side rear wheel
-crawl under and look on the driver side to locate the sensors and bracket
-there are (2) 5mm allen screws holding in both sensors
-if you can remove them without removing the bracket that would be best
(I wasn't so lucky and had to remove the bracket as my reference sensor was stuck in the socket)
-if you have to remove the bracket put the old sensor back in and tape a 8 mm washer on the end of it. Then bolt the bracket back in. The washer will make sure that the new sensor is at the correct spacing.
-Pull the old sensor back out and put the new ones back in.

Also if you do a search there is a thread with pictures showing you how to do it.

Good luck
__________________
1976 911 S Targa 3.2
Old 05-21-2008, 02:55 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #2 (permalink)
Registered
 
burgermeister's Avatar
 
Join Date: May 2007
Location: Springfield
Posts: 2,170
Garage
There is a grommet with the CHT sensor wire in it, as well as the reference sensor wires. It can be a bit of a pain to remove and put back in. Also a clamp in the engine compartment is inconvenient to get to. Still doable, if I can do it in 3 or 4 hours, most folks should be able to do it in 2.

Search for Schnellman's post on reference sensors - he lists a BMW part number from our host that is the same part for $50 less. I have one, and it works.
__________________
'88 Coupe Lagoon Green
"D'ouh!" "Marge - it takes two to lie. One to lie, and one to listen"
"We must not allow a Mineshaft Gap!"
Old 05-21-2008, 03:40 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #3 (permalink)
Registered
 
Join Date: Jan 2007
Location: Vancouver,Canada
Posts: 225
thanks I still want to know whether it works or not before this pita job, cause the car miss sometime not all the time I do check dme , coil , distributor, rotor ground and relay also order new ground stripe ,even head temp sensor ok , etc etc, only this ref and speed sensors is the last point to look after, anyway thanks alot.
__________________
Steve
Old 05-21-2008, 03:42 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #4 (permalink)
Registered
 
ischmitz's Avatar
 
Join Date: May 2002
Location: Santa Barbara, CA
Posts: 4,810
Garage
Send a message via Skype™ to ischmitz
Quote:
Originally Posted by 87 clubsport View Post
Hi everybody according to bentley manual to test the terminal resistance 1 and 2 is 960+- 96 ohm which I within spec, but terminal 1and 3 and 2 and 3 should be > 100000 ohm I cannot get any reading at all, is that means I have to replace both sensor? if I have to replace is that anyway without drop the engine, thanks for you input.
The fact you do not get a reading is GOOD. The sensors have a braided shield on pin 3 and two signal wires on pin 1 and 2 to the internal electric coil. The resistance between the two signal wires is 960 Ohms and there shouldn't be any significant leakage between either signal wire and the braided shielding on pin 3. Based on your measurements the sensors and the cable are perfect. Keep in mind this reading could change once the cables get wet.

Ingo
__________________
1974 Targa 3.6, 2001 C4 (sold), 2019 GT3RS, 2000 ML430

I repair/rebuild Bosch CDI Boxes and Porsche Motronic DMEs
Porsche "Hammer" or Porsche PST2, PIWIS III - I can help!!
How about a NoBadDays DualChip for 964 or '95 993
Old 05-21-2008, 07:54 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #5 (permalink)
Registered
 
Join Date: Jan 2007
Location: Vancouver,Canada
Posts: 225
thanks Ingo, I will leave it and keep driving .
__________________
Steve
Old 05-29-2008, 11:54 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #6 (permalink)
 
Registered
 
Join Date: Jan 2007
Location: Vancouver,Canada
Posts: 225
Bad news after test drive, found engine miss in 2 to 3k rpm , after restart normal again, sometimes drive wholeday nothing happen sometime it happen on and off ,really upset, already change plugs, dme relay fuel pump, filter, even a new coil, clean and balance injectors,any input is welcome.
__________________
Steve
Old 06-24-2008, 09:23 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #7 (permalink)
KTL KTL is offline
Schleprock
 
KTL's Avatar
 
Join Date: Sep 2000
Location: Frankfort IL USA
Posts: 16,639
With the car securely on jackstands, run the engine and jiggle/wiggle the wires where the sensors read the flywheel at the transmission bellhousing. If the missing occurs when you disturb the sensor wires, you need to replace them.
__________________
Kevin L
'86 Carrera "Larry"
Old 06-24-2008, 09:33 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #8 (permalink)
Registered
 
dickster's Avatar
 
Join Date: Nov 2001
Location: a few miles east of USA
Posts: 3,393
I have a cold start problem (doesn't want to pull away) and miss/lumpy idle when warm, otherwise drives great when warm.

I have checked the resistance of both sensors and the speed sensor is slightly out of spec - reading 1095, is that enough to cause problems? I did notice the plastic sheilding is broken near the sensor (when I changed CHT).

Cheers
__________________
Rich

'86 coupe

"there you are"
Old 07-18-2010, 05:24 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #9 (permalink)
Registered
 
steely's Avatar
 
Join Date: Aug 2008
Location: sectors R&N, SE Pa
Posts: 3,117
Hi Rich,

You're just a smidge off, and while I don't know if that be enough to contribute, it could indicate that they are leaking/varying with movement and moisture (not good).

I do think you should change them because as the age, the value will get worse.
If you see crumbling (and you handled them), the problem will accelerate. The insulation on mine just fell off in many pieces as I removed them.
(BMW parts are compatible {Bosch} and less costly)

Also, if you wanted, you could measure the lead resistance of your test leads by touching them together and them subtract that from your 1095 reading, but I doubt it will contribute much.

hth
__________________
Dan

'87 Targa Carrera 3.2 - Fabspeed Cat Bypass, M&K Muffler, SW Chip
Venetian Blue
Old 07-18-2010, 06:12 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #10 (permalink)
Registered
 
dickster's Avatar
 
Join Date: Nov 2001
Location: a few miles east of USA
Posts: 3,393
Thanks Dan
__________________
Rich

'86 coupe

"there you are"
Old 07-18-2010, 06:23 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #11 (permalink)
Registered
 
Join Date: Dec 2007
Posts: 30
Garage
Reference Bracket - 8 mm washer pictures ?

... Ugh.. I found the answer to my question below at:

Gap answer and picture ! 3.2 ref sensor flywheel sensor questions

Regarding "
-if you have to remove the bracket put the old sensor back in and tape a 8 mm washer on the end of it. Then bolt the bracket back in. The washer will make sure that the new sensor is at the correct spacing.
-Pull the old sensor back out and put the new ones back in.
Also if you do a search there is a thread with pictures showing you how to do it. "

Ok, I need to pull the bracket, can someone direct me to the pics on the 8mm washer trick mentioned ?


Last edited by 7thPorsch; 08-15-2014 at 09:01 PM..
Old 08-15-2014, 08:42 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #12 (permalink)
 
Reply


 


All times are GMT -8. The time now is 04:47 AM.


 
Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2025, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2025 Pelican Parts, LLC - Posts may be archived for display on the Pelican Parts Website -    DMCA Registered Agent Contact Page
 

DTO Garage Plus vBulletin Plugins by Drive Thru Online, Inc.