Link 3 Bar MAP sensor fault

[Cr4ig]

Hi all,

Just a question if anyone is aware of or had issues with the 3 Bar map sensors before.

I installed one with my G4X earlier this year and on the first setup of the ECU I had troubles calibrating it as it was out of range compared to BAP, I left it for a day and came back and it calibrated no issue .

Fast forward to this weekend I got some time with the tuner he built up the fuel map for decent idle etc all was good, did some basic road tuning all was well. Pulled over to tidy some things up with the tune and car leaned all the way out and car shut off.

After some discussion and checking of data logs we found that the MAP sensor readings were rapidly changing even though no changes in throttle or anything that would affect vacuum were made.

After pondering today I set up a small test.

Parameters were: engine off sensor at ambient temp and slowly warmed up the MAP sensor with a heat gun on a low temperature setting

As sensor warmed up the MAP output dropped from 101.8 kpa down 30.2kpa before spiking up to 77 kpa. Thermometer reading surface temp of sensor was at 31 degrees C when this rapid swing happened.

Conclusion is heat soak in the engine bay majorly changes the MAP readings. Have contacted the dealer to hopefully get a replacement, but am unsure if I should trust another one if this is a semi common issue ( have heard of one other but unconfirmed which Link MAP sensor was in use)

Have attached a log file for interested peoples. 

Map sensor heat test 2.llgx

[Adamw]

It should be dead stable up to 100C or more.  I believe there was a small batch of faulty MAP sensors some time ago that would vary with temperature, but as far as I remember they were all 4bar versions.  Anyhow, email [email protected] and they should be able to steer you in the right direction to get it replaced.