Notices
928 Forum 1978-1995
Sponsored by:
Sponsored by: 928 Specialists

Cranks speed sensor and harness replacement

Thread Tools
 
Search this Thread
 
Old Apr 14, 2016 | 07:45 AM
  #1  
ollieleven's Avatar
ollieleven
Thread Starter
Track Day
 
Joined: Apr 2016
Posts: 20
Likes: 0
From: London
Default Cranks speed sensor and harness replacement

So my 928 starts first time idles a little low but once engine is hot it won't hold an idle at traffic lights and stalls then it will start but idles so low just stalls again.

It's been at a specialist for couple months they changed temp 2 , TPS, vacuum pipes and a load of other stuff. i bought it home 2 days later once hot did same thing.

I did some digging on rennlist and google and found it might be crank speed sensor playing up when hot so i bought a new one and tried to fit it myself which is pretty tough. i got bolt out and got it moving but have no space to really pull it up and didn't want to snap it off like the 100 horror stories i've read. So i turned my attention to the plug under the throttle wheel pulley. it was in a real mess and so is the harness.


housing broken off in otherside of plug






The harness end was bend 180 back on itself so this had happened.


Does anyone know where i can buy the harness and what it's called. i've found full engine harnesses but they are nearly $1000. i'm in the UK too so local would be a bonus. Thanks in advance i'm new to fixing my own car and the 928 is firmly in the at the deep end
Reply
Old Apr 14, 2016 | 07:55 AM
  #2  
outbackgeorgia's Avatar
outbackgeorgia
Pro
 
Joined: Feb 2010
Posts: 618
Likes: 1
From: Atlanta GA metro, OTP North
Default

Well, just my opinion, but the connector serves only a purpose for vehicle assembly. The sensor itself is very reliable and is NOT a high failure item. It is not periodically replaced. I just cut the connector off each harness, soldered the wires (carefully match colors) using shrink wrap over each splice, and a larger one over the three wires. This is actually a more relible connection than a connecror.
Dave
Reply
Old Apr 14, 2016 | 08:04 AM
  #3  
ollieleven's Avatar
ollieleven
Thread Starter
Track Day
 
Joined: Apr 2016
Posts: 20
Likes: 0
From: London
Default

Originally Posted by outbackgeorgia
Well, just my opinion, but the connector serves only a purpose for vehicle assembly. The sensor itself is very reliable and is NOT a high failure item. It is not periodically replaced. I just cut the connector off each harness, soldered the wires (carefully match colors) using shrink wrap over each splice, and a larger one over the three wires. This is actually a more relible connection than a connecror.
Dave
I was going to try that last night but thought as i had new sensor already was worth changing it. i'd read that the magnets in the sensor degrade after long time and give odd signals when hot. people were recommending changing the CPS as a preventative measure as it's nearly 30 years old.

I'll splice the wires together and see how it runs.

Cheers
Reply
Old Apr 14, 2016 | 08:13 AM
  #4  
Mrmerlin's Avatar
Mrmerlin
Team Owner
20 Year Member
 
Joined: May 2004
Posts: 31,222
Likes: 4,211
From: Philly PA
Default

get a new crank sensor and buy a new 3 pin AMP connector,
Roger has all of what you need and ships to the UK.

NOTE click on user CP at the top of the page ,
and add your vehicle info at the edit signature section.

NOTE I dont suggest using any of the old sensors and fitting new connectors to them,
OK to fit a new connector to the car side of the harness.

to remove the old sensor,
get some mechanics wire and double it up,
then twist the CPS so you can wrap the wire around the CPS,
use a prybar and wrap the wire around it,
and use the prybar to pull the sensor straight up it should come free use PB blaster
Reply
Old Apr 14, 2016 | 08:25 AM
  #5  
ollieleven's Avatar
ollieleven
Thread Starter
Track Day
 
Joined: Apr 2016
Posts: 20
Likes: 0
From: London
Default

Originally Posted by Mrmerlin
get a new crank sensor and buy a new 3 pin AMP connector,
Roger has all of what you need and ships to the UK.

NOTE click on user CP at the top of the page ,
and add your vehicle info at the edit signature section.

NOTE I dont suggest using any of the old sensors and fitting new connectors to them,
OK to fit a new connector to the car side of the harness.

to remove the old sensor,
get some mechanics wire and double it up,
then twist the CPS so you can wrap the wire around the CPS,
use a prybar and wrap the wire around it,
and use the prybar to pull the sensor straight up it should come free use PB blaster
I've been spraying penetrating spray on every day for few days and wiggling it back n forth, i did have some wire but i can't get it under the sensor at all as there is no gap yet. my problem is access. i've taken the MAF out, should i take the throttle pulley and bracket out? there seems to be fuel lines joined to it and the earths looks like a PITA to get out. i feel like it need to take the manifold off to get to it properly but not sure i'm up for that.


Reply
Old Apr 14, 2016 | 10:45 AM
  #6  
ollieleven's Avatar
ollieleven
Thread Starter
Track Day
 
Joined: Apr 2016
Posts: 20
Likes: 0
From: London
Default

[QUOTE=Mrmerlin;13197639]get a new crank sensor and buy a new 3 pin AMP connector,
Roger has all of what you need and ships to the UK.

Who is roger? do you have link to his store?

Thanks for your help !
Reply
Old Apr 14, 2016 | 12:48 PM
  #7  
Mrmerlin's Avatar
Mrmerlin
Team Owner
20 Year Member
 
Joined: May 2004
Posts: 31,222
Likes: 4,211
From: Philly PA
Default

OK you missed the part about twisting the sensor about 60 degrees to have an area to wrap the wire around
Try
Roger@928srus.com
Reply
Old Apr 14, 2016 | 01:43 PM
  #8  
Adk46's Avatar
Adk46
Rennlist Member
10 Year Member
 
Joined: Aug 2014
Posts: 2,480
Likes: 381
From: Adirondack Mountains, New York
Default

"Roger" means 928srus.com. You would find something comforting about him if you got him on the phone.
Reply
Rennlist Stories

The Best Porsche Posts for Porsche Enthusiasts

story-0

9 Features and Characteristics That Only Porsche People Understand

 Verdad Gallardo
story-1

I've Written 500 Rennlist Articles: Here's How Porsche Has Changed Along the Way

 Joe Kucinski
story-2

10 Most Unnecessary Porsches Ever Built (And Why We Love Them)

 Verdad Gallardo
story-3

Porsche 911 GT3 S/C vs 718 Spyder RS: 10 Categories, One Winner

 Joe Kucinski
story-4

This Builder Is Turning Heads With Its Slantnose 911 Creation

 Verdad Gallardo
story-5

Porsche 911 GT3 Artisan Edition Pays Homage to Japanese Culture

 Verdad Gallardo
story-6

Porsche Reveals Coupe Variant of the Electric Cayenne With a Fresh Look

 Verdad Gallardo
story-7

10 Porsche Colors That Have More Personality Than Most People

 Verdad Gallardo
story-8

Guntherwerks' Final Speedster Creation Is the Ultimate Porsche Restomod

 Verdad Gallardo
story-9

10 Reasons I Hate Going to the Porsche Dealership (& the 1 Reason I Stay)

 Joe Kucinski
Old Apr 14, 2016 | 03:50 PM
  #9  
ollieleven's Avatar
ollieleven
Thread Starter
Track Day
 
Joined: Apr 2016
Posts: 20
Likes: 0
From: London
Default

Awesome i'll give it a try again with the wire. i managed to find a connector on ebay shipping from Australia i'm london so i'll see if roger might be quicker.

Thank for your help!
Reply




All times are GMT -3. The time now is 04:34 PM.

story-0
9 Features and Characteristics That Only Porsche People Understand

Slideshow: Some brands build cars. Porsche builds traditions, obsessions, and a few habits that stopped making sense decades ago but somehow became part of the charm.

By Verdad Gallardo | 2026-05-13 18:46:13


VIEW MORE
story-1
I've Written 500 Rennlist Articles: Here's How Porsche Has Changed Along the Way

Slideshow: Six years and 500 Rennlist articles later, these are the biggest changes at Porsche.

By Joe Kucinski | 2026-05-11 09:52:55


VIEW MORE
story-2
10 Most Unnecessary Porsches Ever Built (And Why We Love Them)

Slideshow: Some Porsches exist for very specific reasons-others feel like they were built just to see if anyone would notice.

By Verdad Gallardo | 2026-05-06 18:00:32


VIEW MORE
story-3
Porsche 911 GT3 S/C vs 718 Spyder RS: 10 Categories, One Winner

Slideshow: Choosing between the 911 GT3 S/C and 718 Spyder RS in 10 key categories to determine one surprising winner.

By Joe Kucinski | 2026-05-05 12:51:46


VIEW MORE
story-4
This Builder Is Turning Heads With Its Slantnose 911 Creation

Slideshow: A small Polish tuner has reimagined the Porsche 911 Slantnose for the modern era, blending 1980s nostalgia with widebody tuning culture and serious performance upgrades.

By Verdad Gallardo | 2026-05-01 10:49:43


VIEW MORE
story-5
Porsche 911 GT3 Artisan Edition Pays Homage to Japanese Culture

Slideshow: Porsche has created a Japan-only 911 GT3 Artisan Edition that blends track-ready hardware with design cues inspired by traditional Japanese craftsmanship.

By Verdad Gallardo | 2026-04-28 19:37:40


VIEW MORE
story-6
Porsche Reveals Coupe Variant of the Electric Cayenne With a Fresh Look

Slideshow: Porsche's latest electric Cayenne Coupe blends dramatic styling with supercar acceleration, turning the brand's midsize SUV into a 1,139-horsepower flagship.

By Verdad Gallardo | 2026-04-27 19:39:30


VIEW MORE
story-7
10 Porsche Colors That Have More Personality Than Most People

Slideshow: Porsche's wildest paint colors aren't just shades-they're full-blown personalities on four wheels.

By Verdad Gallardo | 2026-04-27 19:38:13


VIEW MORE
story-8
Guntherwerks' Final Speedster Creation Is the Ultimate Porsche Restomod

Slideshow: The last of the Speedsters doesn't just close a chapter, it makes quite the bold, air-cooled statement.

By Verdad Gallardo | 2026-04-22 17:55:04


VIEW MORE
story-9
10 Reasons I Hate Going to the Porsche Dealership (& the 1 Reason I Stay)

Slideshow: Going to a Porsche dealership may not be the dream experience you expect it to be and these are the reasons why.

By Joe Kucinski | 2026-04-21 13:54:19


VIEW MORE