scoobymark66

Hi guys.

Will be fitting a MY98 MAP sensor to my MY93 so I can run 1.2 bar boost without hitting fuel cut.

Assuming I am holding the new sensor with the boost/vacuum pipe pointing down wards which is the power/ground and sensor pins. Unfortunately I did not get a plug with it so will be soldering direct to the pins.

Thank you in advance.

Cheers. Mark.

sparkplug

For some reason I didn’t think you could fit a later map sensor to a classic due to its output differences not 100% sure though.

scoobymark66

Hi.

The different output is the reason for fitting the later MAP sensor.
It means you can raise the boost without hitting the fuel cut point which is lower on the earlier cars.

Cheers. Mark.

nickwrxstiV2

I thought the fuel cut was governed by the ECU?

If you are fitting the later MAP sensor, the output voltages differ from the earlier MAP sensor, hence you will have to have it rescaled.

coulty

I have done this mod a long time ago. It doesn't make a difference about it and rescaling is not necessary even if you had an apexi power fc. I have the two wiring diagrams for the conversion if anyone wants them.

Stuart

scoobymark66

Yes please Stuart that is just what I am after. The only thing is as I said in my post I do not have the wires for the later sensor.
Could you give me the info as in left pin middle pin and right pin?

Thank you.

Mark.

nickwrxstiV2

Mark - where did you get the MAP sensor from and how much? Hope you don't mind me asking cos I was thinking of doing little by little to my MY96 STI, thanks.

Nick.

scoobymark66

Hi Nick.

I got the whole boost control pack off ebay for £7.50 plus £8 postage.
Fiestaboy on here has one but he wants £30 for it!

Cheers. Mark.

coulty

Let me know your email address and i will send them.

It doesn't matter about the wiring as you will cut into the old wiring anyway and you can use spade connectors.

scoobymark66

*******@calthorpe.eclipse.co.uk

Cheers. Mark.

nickwrxstiV2

Would installing a late MAP sensor get rid of fuel cut?

I thought that fuel cut was set at 1.2bar by the ECU?

scoobymark66

Hi Nick.

The later MAP sensor does not get rid of the fuel cut. It just moves it to a higher point (aprox 1.8 bar I think). It is the MAP sensor that tells the ECU it has reached max boost therefore cut the fuel.

I hope I have all of the above correct and it is of some use.

Cheers. Mark.

nickwrxstiV2

Found this in a previous thread by Scott.T-


If you are using the standard boost control then you will need to get it remapped. there are a few values in the map that can be altered to cater for the later map sensor.

If you are using a Dawes or mechanical boost controller it should work O.K

The voltage the ECU expects to see for 1 BAR on the original sensor is about 4.5V, the later map sensor only output 3.78V at 1 BAR.

So basically the ECU will try to achieve 4.5V by cranking up the boost control duty (within it's mapped limits). But 4.5V on the later map sensor is going to give you 1.5bar.

I've never tried this and doubt it will achieve it, but expect the boost control, escpecially in the higher gears, will be all over the place.

scoobymark66

Hi Nick.

That explains how the later MAP sensor raises the fuel cut. It shows the ECU a lower voltage for any given boost value. This means the ECU sees a lower boost than is actually being produced.

The 'all over the place' boost is will be controlled by the electronic boost controller so removing control from the ECU.

Cheers. Mark.