3bar map sensor idle problem

[ababaz]

hello
i bought a 3 bar map sensor (http://www.ebay.fr/itm/3-BAR-MAP-SENSOR-FORD-SIERRA-Hatchback-GBC-GBG-2-0-RS-Cosworth-11-87-01-90-/171145900511?hash=item27d91731df)
to suit my turbo jp4 project.

im still on oem ecu, i just wanted to start the car to see if she runs fine.
when i started the engine with the 3bar map sensor, it wont idle and runs rough.. when i plug the oem map sensor (100kpa) its runs fine.

i heard about voltage scaling because its a 3 bar map but i dont know more...if someone can explain me how to fix it

thank you

[AXracing]

Normally you would not instal a 3 bar map sensor until you ready to run boost. Personally I would just take it back out.

You can get the stock ECU mapped to work with it though.

The other option is use a piggyback ECU to trick the stock ECU in to behaving.

Next option is replace hole ECU and have it mapped accordingly.

[ababaz]

hello
sorry i forgot to mention that i will use a piggyback AEM FIC6 to trick the oem ecu and run the car with a decent mapping, just waiting on a friend to help me out installing it..

btw, will i have the same problem with the 3 bar map sensor once ill get the fic wired ?

[Chipwizards]

I replied to your PM.

But for public information your Marelli 8P ECU is probably not well suited to a boosted application because the load axis is only 9 bytes wide so the resolution would be poor for a boosted application.

A better solution would be to fit the later MM48P2.80 (three plug) ECU and map that to suit your boosted application. The success of this solution will depend on whether you have someone local to you able to map it for you?

If you decide to fit an aftermarket ECU then knock control would be very strongly recommended for you 300bhp target. The stock ECUs have it of course if you are using one.