Hi, i recently installed a stock Greddy kit on my 1992 Eunos Roadster 1.6l.
Now i thought i had a 2-bar MAP sensor, turns out it is more than likely a 2.5-bar sensor (Weber APS02/02). Ok, not a problem.
But, using the MAP sensor as throttle position sensor I could only get a reading of 60% throttle when maxing out the motor, and 43% with just the ignition turned on (atmospheric pressure).
After some studying and talking to some other guys, if the calculations are correct, then I am actually running 8psi.... from a stock Greddy kit!!??

Firstly, i thought the Greddy kits were set to make 5psi straight out the box? NOT 8psi!!?? I have done nothing to it part from install it.

Secondly, i'm non-intercooled, so i REALLY need to wind down the boost before my pistons become molten blobs of metal Is it simply a case of adjusting the actuator rod to make it a little longer?

*Assuming all calculations are correct.

I'd appreciate all your opinions on this, thanks. Jim.

 

yeah i would verify this with a mechanical guage to see if the map is in the right ball park, also check the output and make sure it is linear for the range.

 

Maybe the calibration of the MAP sensor is screwed up. I bought it used, so it could be that..

 

what are you even calculating and reading off of?

what does it display when the car is off?

 

I'm using e-manage blue.
I have the MAP sensor going to the TPS, and my wideband o2 is connected into the "boost" port on the e-manage.
MAP sensor is Marelli/Weber APS02/02 (i believe it to be a 2.5bar sensor)
Wideband is the AEM guage type.

With the ignition ON, but engine OFF it's saying the throttle position is 43%, and at idle i get a reading of 13%. By my calculations, for a 2.5Bar MAP sensor, there is something wrong there
I still have the AFPR connected up. But before installing the e-manage, just running the stock Greddy kit, it was running quite lean. strange.

Anyhow, i've fitted a boost guage, and that shows 5psi max. so i'm thinking that it must be a Problem with the MAP sensor. I've checked all vacuum lines & connections and they are ok.
I'm going to try a 2bar weber APS02/03 sensor, see what happens with that...

 

good plan

 

So i tried a different MAP sensor. An APS 02/03 weber one.
And the damn readings are still the same!!! AArrrrrrgh!!!
TPS reading is 44% (ignition ON, engine OFF), should it not be 49% or something? TPS is 13% at idle. Still only reaching 60% throttle position when doing a power-run.

Well, everything else on the emanage seems to be working fine, so i can only assume it is my useless wiring on the MAP sensor side, or maybe i could try a new plug to put in the "boost" port on the emanage.

So, AFR's seem fine. Boost guage tells me 5psi, engine sounds good.
All this MAP sensor problem is doing is stopping me from tuning properly right?

 

This is precisely why I tell the EMU folks to bite the bullet and spend the $100 that Greddy wants for the "official" 4 bar MAP sensor...

 

If you are feeding to the TPS input, you must first set up a scale. Feed the signal to the pressure sensor input and then calculate your boost based on the voltage output of your specific MAP sensor.