[928uk] NTC2 variants - was Cheap LH-Jetronic temp sensor II NTC2

Sun Jun 2 09:21:29 UTC 2024

I’ve retitled this thread NTC2 variants, got rid of all the reply arrows (please turn these off if you can), and snipped last year’s stuff as the thread had become huge and difficult to read.

My 928 GT has an FAE 33090 that I fitted last Feb. It measured within spec at garage temp (around 15C) back then, and the car runs fine with it. I didn’t check it at higher temperatures. It has ‘FAE 33090’ stamped on the brass housing.

Simon, is your FAE sensor a 33090? Does it have ‘FAE 33090’ stamped on the brass housing? Where did you buy it?

Best regards,
Jonathan

1991 928 GT Amethyst Metallic

From: Simon Painter <simonpainter101 at gmail.com> 
Sent: 02 June 2024 08:40
To: jonathan at rackowe.net
Cc: Paul <ukkid35 at gmail.com>; 928 List <928uk at lists.928.org.uk>
Subject: Re: [928uk] Cheap LH-Jetronic temp sensor II NTC2

The FAE Temp2 sensor reads:

20C - 5.3k

32C - 4k

46C - 2.4k

60C - 1.5k

70C - 0.93k

I was quite surprised how the Temp2 sensor affects starting. I have an ongoing issue with re-starting when hot, eg re-starting after filling fuel. It will turn over quite slowly compared to a cold start. One day after a fuel stop, I unplugged the Temp2 connector and just plugged in a new FAE sensor and left it hanging loose. The engine turned over really quickly! It didn’t want to start as it was probably running with a super rich mixture as the Temp2 sensor was cold and engine hot.

I’m pretty sure my original Bosch Temp2 sensor is causing my hot re-start issue but I have yet to find a good replacement that is in spec.

Thanks

Simon.

Check me out on Instagram and Facebook @oldcarfixer

On 1 Jun 2024, at 23:41, Jonathan Rackowe <jonathanrackowe at gmail.com <mailto:jonathanrackowe at gmail.com> > wrote:

What does your FAE one measure Simon?

Best regards 

Jonathan 

1991 928 GT Amethyst Metallic 

  _____  

On Sat, 1 Jun 2024, 3:55 pm Simon Painter, <simonpainter101 at gmail.com <mailto:simonpainter101 at gmail.com> > wrote:

I’ve now bought two (one an FAE) and both measure way off what they are supposed to be. I’m trying to get gold of an original Bosch one.

Thanks

Simon.

  _____  

-----Original Message-----
On 1 Jun 2024, at 15:51, Jonathan Rackowe via 928uk <928uk at lists.928.org.uk <mailto:928uk at lists.928.org.uk> > wrote:

Definitely one to return as defective.

Maybe Vince can sell you one of the several FAE ones that he bought to keep them in the 928 community.

Best regards 

Jonathan 

1991 928 GT Amethyst Metallic 

-----Original Message-----
On Sat, 1 Jun 2024, 3:42 pm Paul, <ukkid35 at gmail.com <mailto:ukkid35 at gmail.com> > wrote:

15C - 6k
60C - 1.2k

Both circuits measured the same, on old and new sensor

Paul

-----Original Message-----
On Sat, 1 Jun 2024 at 15:36, Jonathan Rackowe <jonathanrackowe at gmail.com <mailto:jonathanrackowe at gmail.com> >
wrote:

What were your measured results at 15C and 60C Paul?

Best regards 

Jonathan 

1991 928 GT Amethyst Metallic 

-----Original Message-----

On Sat, 1 Jun 2024, 1:20 pm Paul, <ukkid35 at gmail.com <mailto:ukkid35 at gmail.com> > wrote:

Sadly the Lemark sensor I bought is faulty, or at least off spec

I compared it with the old one, and with the specs, and found that the new sensor reads approximately double the resistance that it should, checking at 15C and 60C

The Temp Sensor II resistance measurements should be:

0 C / 32 F:  4.4k to 6.0k Ohms
15 - 30 C / 59 - 86 F: 1.4k to 3.6k Ohms
40 C / 104 F: 0.9 to 1.3k Ohm
60 C / 140 F: 480 to 720 Ohms
80 C / 176 F: 250 to 390 Ohm

Disappointing

Paul

87 S4 Manual

  _____  

-----Original Message-----
On Mon, 20 May 2024 at 17:47, <jonathanrackowe at gmail.com <mailto:jonathanrackowe at gmail.com> > wrote:

Hi Paul,

That's a Lemark one, not an FAE33090, but it'll probably work just as well and good to have any version as a spare.

Best regards,

Jonathan

1991 928 GT Amethyst Metallic

-----Original Message-----

From: 928uk <928uk-bounces at lists.928.org.uk <mailto:928uk-bounces at lists.928.org.uk> > On Behalf Of Paul via 928uk

Sent: 20 May 2024 14:46

To: 928uk at lists.928.org.uk <mailto:928uk at lists.928.org.uk> 

Subject: Re: [928uk] Cheap LH-Jetronic temp sensor II NTC2

A week ago I drove back from Germany in my other car, which had suffered a

coolant temp sensor failure, not a pleasant or relaxing experience, as the

rad fans never came on

I don't want to risk the same in the 928 so I've just bought an FAE 33090,

for the same price as last year, result!

https://www.ebay.co.uk/itm/355597952746

Paul

87 S4 Manual