Author Topic: Temperature sensors (Read 4410 times)

Bill K · « **on:** November 06, 2010, 07:44:34 PM »

Hi Guys
My 1995 M42 is fitted with a DA supercharger kit but recent tuning on a dyno indicates that the air-fuel ratio is very lean, particularly at low revs and under full throttle conditions. The fuel side (pressure and flow) checked out OK so it is suspected that the coolant temperature sensor may be sending inaccurate readings to the ECU. There are 2 temperature sensors located on the LH side of the head under the intake manifold - one for the temp gauge and the other for the ECU. Can anyone please advise which is the transmitter used by the ECU?
Bill K

Ryann · « **Reply #1 on:** November 06, 2010, 08:08:49 PM »

Quote from: Bill K;98409

My 1995 M42 is fitted with a DA supercharger kit..

Lucky. Post up some pics! Show us your dyno sheet!

The coolant temp. sensor for the injection system is just behind the timing cover beneath #1 intake runner. Below are the correct resistance values for the ECTS used by the DME:

@68 degrees F, ohms should be 2.1-2.9
@176 degrees F, ohms should be .27-.40

DesktopDave · « **Reply #2 on:** November 06, 2010, 09:27:44 PM »

You're in KOhms there, not ohms...

@68degF is 2100 to 2900 ohms
operating temp...270-400 ohms

I can't recall which temp sender is which on the e36. Isn't the front coolant temp sensor for the DME? Has a two wire harness? The one further back is the gauge sender, with one wire IIRC.

Don't forget to test the intake air temp sensor too.

bmwconnect · « **Reply #3 on:** November 06, 2010, 11:25:17 PM »

Quote from: Bill K;98409

Hi Guys
My 1995 M42 is fitted with a DA supercharger kit but recent tuning on a dyno indicates that the air-fuel ratio is very lean, particularly at low revs and under full throttle conditions. The fuel side (pressure and flow) checked out OK so it is suspected that the coolant temperature sensor may be sending inaccurate readings to the ECU. There are 2 temperature sensors located on the LH side of the head under the intake manifold - one for the temp gauge and the other for the ECU. Can anyone please advise which is the transmitter used by the ECU?
Bill K

do you mean recent run's on the dyno with a post cat sniffer? What are you running for engine management or fuel management ? Please post the Dyno runs with Afrs

The coolant temp sensor is really only used on cold start up or until the car reaches operating temp then the DME shifts the priority to the air temp sensor for it's main source of info to increase or decrease fuel

I would suspect a air temp sensor and it should be tested as dave has pointed out

Ryann · « **Reply #4 on:** November 06, 2010, 11:32:05 PM »

Quote from: DesktopDave;98411

You're in KOhms there, not ohms...

Hm, could be. That temp/ohms info is straight out of my Bentley. I don't recall seeing Kohms, but it wouldn't matter with my multimeter.

Bill K · « **Reply #5 on:** November 07, 2010, 07:42:46 PM »

Thanks guys. I have tried to post my dyno charts and report but despite zipping them they are still being rejected as too large. I will try to send to each of you by PM, if that's OK. Am new to Forum and having troubles getting the hang of how to work within it, sorry.

bmwconnect · « **Reply #6 on:** November 07, 2010, 07:58:37 PM »

Quote from: Bill K;98442

Thanks guys. I have tried to post my dyno charts and report but despite zipping them they are still being rejected as too large. I will try to send to each of you by PM, if that's OK. Am new to Forum and having troubles getting the hang of how to work within it, sorry.

I can post em up here just send to my email midnight-tuning@rogers.com

Regards|