VE MAP Sensor

[uglyoldfatbastard]

Although not the same engine it's very similar and it is the same sensor

Manifold Insulator / Spacer Installation – VE Commodore | AutoInstruct

This guide will show you how to install a manifold insulator / spacer in your VE or VF Commodore. This guide is only applicable for LFX engines (MY12+).

www.autoinstruct.com.au

 

[lmoengnr]

Don't the V6's run a vacuum pump cause intake vacuum is F/all?

 

[Fu Manchu]

The MAP sensor on V6 Alloytec doesn’t read internal Manifold Air Pressure. Instead it’s used to measure external air pressure to provide data for fuelling by the ECM.
The data you see varies because one shows atmospheric air pressure via MAP sensor and the other sees internal manifold pressure.

Same measurements that a barometer would gather on a weather station. When you used to see the pressure figures on the weather map.

1031 centre of the high over SA/Vic.

That’s at sea level. That pressure changes with altitude as well. This affects air density. That data is used in fuel trims.

 

[07GTS]

if there is a map sensor on the outside of manifold then its purely for barometric pressure, before then it was the map sensor in the engine used for baro when key was on before engine started

 

[Fu Manchu]

I believe it’s the same one used on V8 as well, only with the V8 it’s used for internal air pressure in the intake manifold.

 

[Marty 66]

Thanks again for the replies.

So basically the VE is reading correct as it is not reading internal manifold pressure - just atmospheric and this accounts for the static 14.2psi reading.

The VF is reading both manifold & atmospheric so I can read a Baro & Intake value on the VF with the Torque Pro App. Baro stays static on the VF at 14.4psi and the Intake psi varies as described.

Is that correct ?

It does appear strange though that the MAP sensor has an O Ring and is meant to be "plugged in" to the manifold to create a seal as if it was meant to measure manifold internal vacuum ?

Thanks

 

[Fu Manchu]

That’s an air pressure of about 980hPa so a deep low near your house or you might live at an elevation.

It might be reading incorrectly because current air pressure over SA is quite high at 1026. Even if you live in the hills it might be 1015.