M44 in E30 - Issues...

[Royalratch]

Still on this problem.

M44 Block with double temp sensor that needs to fit E30 loom/ECU/clocks.

Can anyone tell me if the temp reading will be accurate for both? Will it be the correct 'signal' to feed an E30 ECU and E30 Temp Gauge etc?

If so, surely that is the best way and requires no loom work at all?

[sheepdog]

Still on this problem.

M44 Block with double temp sensor that needs to fit E30 loom/ECU/clocks.

Can anyone tell me if the temp reading will be accurate for both? Will it be the correct 'signal' to feed an E30 ECU and E30 Temp Gauge etc?

If so, surely that is the best way and requires no loom work at all?

Odds are it will work fine.

If not, use the head one with m42 sensor for the computer and a secondary one for the gauge.

[jakeb]

Kind of a side questions but which is for the gauge temp?

in the m42 head.

jake

[Royalratch]

To clarify.

In the M44 there is a double temperature sensor located in ONE port that feeds both temp gauge AND ECU.

M42's in an E30 have TWO sensors feeding gauge and ECU separately.

So I have an M44 in an E30 whose loom needs two separate signals and my questions are:

1) Does the M44 double temp sensor feed an identical or usable signal as the M42 sensors?

2) Looking closer still, are the individual signals for the ECU and gauge the same or different?

I would assume that a sensor just takes a given reading at the head, and it's the gauge or ECU that 'interprets' that signal into what it needs. Can I measure these signals somehow? Is there info on it somewhere?

[sheepdog]

1) Does the M44 double temp sensor feed an identical or usable signal as the M42 sensors?

2) Looking closer still, are the individual signals for the ECU and gauge the same or different?

Pretty sure in both cases they are the same, I have read of others using it with success.

[Royalratch]

I am now doing this - M44 Double Temp feeding M42 temp gauge and ECU - will let you know when it's up and running.

[sheepdog]

I am now doing this - M44 Double Temp feeding M42 temp gauge and ECU - will let you know when it's up and running.

Document as much as you can please.

[Royalratch]

Okay.

The guys I'm working with on this are running into a little trouble. As Sheepdog has pointed out, there has been some success with getting the single M44 Double Temp Sensor to feed the E30 temp gauge and engine ECU.

However, my guys cannot get the gauge to work. They have 4 pinouts from the M44 TS, 2 for the gauge and 2 for the ECU right?

What they need to know is if there is any info regarding colour of wires, voltage/resistance, pin numbers etc that need to be a certain value.

Any help would be great as it's all ready to rock and it runs fine but obviously no temp gauge is not cool (!).

[johna]

According to the E36 Bentley manual:

* Pin 1 of the temp sensor is brown/yellow wire and goes to the instrument cluster (temp sens negative)
* Pin 2 of the temp sensor is brown/violet wire and goes to the instrument cluster (temp sens positive)
* Pin 3 of the temp sensor is brown/red wire and goes to the engine control module (temp signal)
* Pin 4 of the temp sensor is brown/black wire and goes to a common ground point shared with the knock sensors, throttle position sensor, then back to the engine control module (sensor ground)

(Wire colours are from M44 loom)

Comparing this to the E30 wiring diagram:

* Connect the E30s wiring loom brown/black wire to pin 4 of the sensor
* Connect the E30s wiring loom brown/red wire to pin 3 of the sensor

That should do it for the engine computer.

The instrument cluster is a bit trickier.

I would try the brown/violet wire to pin 2 and then run a ground to pin 1 (that will be the other wire that ran to the M42 sensor, I don't know the colour of that one). If that doesn't work I would reverse those two.

[Royalratch]

It appears that getting a correct gauge reading is the ongoing problem here (without drilling or re-positioning the temp sensor).

The M42 / E30 ECU's don't have or use knock sensors right - could that be what complicates matters here?

Appreciate that help bud. Will let you know what happens ASAP.

[Royalratch]

Looks like the temp sensor issue is impossible to sort as with 3 days of tweaking we cannot get a reliable signal to the gauge from the M44 Dual feed Sensor. The only sure way is to stick the original M42 sensor in the water pipe or thermostat housing. I have found this to at least make it look tidy:

[Royalratch]

Hello all again.

The above solution now works fine. Temp gauge reads dead centre and engine runs fine. Some small cosmetic tweaks are being done then I'll post a full write-up in a separate thread.

Thanks for the pointers!

[KyleTaylor]

To bring to life an old thread with new information I must add the following.

The 4 prong e36 sensor cannot be used with the e30 for temp gauge signal.  The e36 uses a different signal threshold.  This is a known issue with the m50 conversion.  The e30 gauge its matching e30 sensor.  As for the DME signal, I would venture to say it is e30 specific as well.  

When using e30 DME to control the m44 use correct e30 temp sensor for DME.
Use e30 temp sensor for the e30 gauge.

[Royalratch]

When using e30 DME to control the m44 use correct e30 temp sensor for DME.
Use e30 temp sensor for the e30 gauge.

Yes but, 2 sensors into 1 port does not go. (M44 Block has single port to feed both ECu and Temp Gauge).

The signal from the thermostat housing or water pipe will never be accurate because it's not as hot as the block housing.

[KyleTaylor]

Yes but, 2 sensors into 1 port does not go. (M44 Block has single port to feed both ECu and Temp Gauge).

The signal from the thermostat housing or water pipe will never be accurate because it's not as hot as the block housing.

I would say use the head port for the DME signal.  And the one at the thermostat for the gauge.  The gauge is important, but the one for the DME is more so.

Coolant temp should not change much across the head.  At least not enough to cause the gauge to behave as others are describing.