MAP sensor, piggybacks ...

[jmc007]

Is there a MAP sensor on the LSJ ?

Those who are interested to learn more about Piggybacks, here is a good link:

http://www.exhaustdepot.net/

Go in the SRT-4 section, then in the SRT-4 Tech section, then in the Piggy Back Computer 101 ...

Any suggestions ?

[my_bd]

Originally Posted by jmc007

Is there a MAP sensor on the LSJ ?

Those who are interested to learn more about Piggybacks, here is a good link:

http://www.exhaustdepot.net/

Go in the SRT-4 section, then in the SRT-4 Tech section, then in the Piggy Back Computer 101 ...

Any suggestions ?

wow!
I hope someday there'll be a site like that for the RL!!

[MotorMouth]

Originally Posted by jmc007

Is there a MAP sensor on the LSJ ?

Yup, three of them actually. As well as a MAF sensor.

[ray@revitup]

Originally Posted by MotorMouth

Yup, three of them actually. As well as a MAF sensor.

thats what makes this car a pita to get a piggyback working correct. if one sensor sees a different voltage. hello limp mode

[jmc007]

You mean there is 3 manifold absolute pressure sensors ? What kind of signal they provide to the ECU, voltage ?

[WhatsADSM]

Originally Posted by MotorMouth

Yup, three of them actually. As well as a MAF sensor.

Can you elaborate on this?

If it truly has 4 different methods of calculating incoming air quantity I don't understand how any piggyback would have a chance.

i only ask because PSI-Fi includes a small piggy back in with their kit...

[Sp00ner]

I'm curious as hell too, why does the car require 3 seperate ones? Are they in different locations, are they there just to check the other ones? Did they just have extra MAP sensors for that year? I know Psi-Fi had a hell of a time getting the PB to run without throwing codes left and right...

[MotorMouth]

Originally Posted by WhatsADSM

Can you elaborate on this?

If it truly has 4 different methods of calculating incoming air quantity I don't understand how any piggyback would have a chance.

i only ask because PSI-Fi includes a small piggy back in with their kit...

All I can tell you is what I know about them wich is not much. There is one on top of the blower that measures supercharger inlet pressure. The second that is mounted on the driver side of the motor that only measures atmospheric pressure. The third that is mounted on the intake on the passanger side just under the fuel rail that measures intake pressure. I believe this MAP sensor also has an integrated intake temp sensor as well (don't quote me on that though). Then there is the MAF sensor wich I believe as well has an integtated temp sensor.

[pclear9061]

could it be

1) timing
2) air
3) fuel

[DanM]

There are three PRESSURE sensors. Not per-se three "MAP" sensors (because MAP = Manifold pressure, and all three of them aren't in the manifold).

The three sensors he's referring to are (1) MAP sensor in the manifold after the supercharger. (2) SC Inlet pressure sensor downstream of the TB, but before the SC. (3) Baro or atmospheric pressure sensor for comparison.

He is right though in saying that you can't just put some kind of piggyback on the MAP sensor and expect to get by like that. Just ask Psi-Fi. There are a whole whack of rationality diagnostics that compare the readings on all three sensors (as well as MAF, pre & post SC temp, throttle position, etc) to make sure they all agree and something isn't wrong. If you try to just "clamp" or mess with one of them, you will end up in reduced engine power/limp mode.