Darien

This was an unknown when we finished the SC install. Anyone recognize it? It has temp's stamped 87.2, 82.50 deg. It also has a number 160.31 stamped on it.

Tony

I cant remeber where it came from..is it #36?

Also...i may have them backwards..but see the two sensors on the water manifld under the SC snout..the top one is TEAL..the bottom is GOLD?
One is water temp..the the other is a temp sensor for fuel enrichment for cold starts and is fed to the Brains etc...Correct if im wrong folks.

I believe the one your wondering about was for the fans..and bolted onto the surface of the intake manifold..it doesnt measure an AIR temp..or intake air temp ...its to slow and not nearly accurate enough to do that. Im almost positive this sensor has nothing to do with fueling? Anyone?

Bill Ball

That would be the intake air temp sensor. It affects fan operation. I'm not sure if it affects fuel mixture (John?). I think it just affects the fans.

In Andy's configuration, he simply attached it to the top of the manifold by tiewrapping it to a protrudig bolt. Ideally, you would thread it into the manifold. I've had mine sitting on the top of the manifold for two years.

Bill Ball

As Jim Bailey reminded me, the 86MY and before do not have the S4 type electric fans. So, this is a manifold air temp sensor, if it is 36, but I'm not sure what it drives. I would have to look it up.

Bill Ball

Well it goes to the EZF. This will get you started...

Jim bailey - 928 International

My guess is it retards timing when the intake temp is high.....

Tony

Hmmm..perhaps we need to find a good place for it then?

I figured it was cold starts.sensing the general temp of the motor?

thanks!

Jim bailey - 928 International

It is temp sensor I and defects it causes...".poor engine output ...engine knocks when accelerating " you had to make me look it definately retards the timing on 85-86 (euro LH as well)

Sharks

Tony/Bill, you are correct that is the intake temp sensor. It measures skin temp of the manifold (Darien look at your manifold and you will find the threaded hole that it goes into ... the hole is blocked from the airflow).

I welded a nut onto my intake and threaded it in. I wasn't sure what it did so I thought I better keep it doing the same thing.

Bill Ball

Jim, thanks. The WSM labels this as temp sensor 1 (air temp sensor) and it does affect ignition timing, saying it can affect power output and pinging on acceleration in a troubleshooting chart. It has no connection to the LH. However, in the 87 and later S4, it isn't mentioned at all in the LH or EZK sections of the WSM. It appears to me from the wiring diagrams, this sensor only provides input to the cooling fans in the S4, but inputs to the ignition system in S3. Never noticed that before. So, it may be rather important in Darien's car to have this mounted in the intake airflow and less so in my S4.

worf928

Does WSM have the resistance specs for this sensor? (I confess that I have not looked for them...)

AO

On mine, it screws into the rear of the SC housing. Not sure if this is a factory location or if DR tapped it. Sorry, this is the best picture I have.

Sharks

Here is were I installed mine. Nut welded under the intake prior to install.

Bill Ball

For 84-86:

Connect ohmmeter between terminals 10 and 22 on disconnected plug of electronic ignition control unit.
Specifications:
0C (32F) = 4.4 to 6.8 kOhm
15 to 30C (59 to 86F) = 1.4 to 3.6 kOhm
40C (104F) = 0.9 to 1.3 kOhm

I don't see the spec yet for later cars, but this sensor can cause the fans to run on for a long time after the car is shut off if it is faulty.

Bill Ball

My concern with mounting it ON the outside of the intake or blower rather than in the airflow, at least for 84-86 where it affects ignition timing, is that you are measuring the blower case temp, which could get heat-soaked, while the air temp inside could be much different. Also, mounting it on the intake side rather than the manifold side of the blower could give you very different readings. This location is far less important for NA engines as the intake air does not get compressed and heated. I'm less concerned on my 89 since this sensor seems not to play any role in timing or fuel.