MAP = 80 kPa?

[Scourage]

I have a 2010 Camaro, Whippled and ZR1 MAP sensor. I tried to set up a data log for boost and noticed that MAP reads 80 kPa and boost [PID.11]-14.5 is at 65.5 PSI with KOEO.
I have linear at 312.50 and offset -11.25 for the MAP sensor. After doing some searching, I tried the custom 2 bar OS and still get the same data. Any ideas what is wrong here

[DWC]

14.5 Boost should be showing 200 kPA do you have your PID set up for two decimal places?

[jimmyblue]

Look for the custom-OS-specific MAP (includes the multi-
bar MAP sensor scaling) and use that instead.

If you're at very high altitude your KOEO MAP would read
lower than the sea level 101kPa. Not sure what the
elevation would have to be, to get as low as 80.

[DWC]

Also look at the volts of your MAP sensor to make sure it's 2 bar.

[Scourage]

I've verified the P/N of the MAP sensor, it is correct.
KOEO Map even at 6K feet shouldn't be 80 kPa.

I went to the custom OS after doing some research and following this guide http://www.hptuners.com/help/vcm_edi...ters_gm_os.htm but I didn't see that option from line 20 for the Gen III; "(This step for 2bar and 3bar enhancement only) Right-click again on the table display cell and select "Insert", go to the Engine -> Airflow section and choose either the "Manifold Air Pressure - 2 bar" or "Manifold Air Pressure - 3 bar" PID, double-click to insert it into the table."

I've deleted the VCM Scanner config after each write to make sure it's not keeping an old one.
This is from tonight, my current tune with the ZR1 MAP data and it shows 82 kPa as MAP;
Current Tune 9-25.hpt
This is with the custom OS and it still shows 82 kPa;
2 bar custom OS 9-25b.hpt

I even put the stock data in for the MAP and it was reading 37 kPa, I dunno, maybe I got a bad sensor.
Guess I'll try and find the pin-out and check that voltage.

[Scourage]

Just realized I posted in the Gen 3 section, anyway I checked the voltage output from the MAP sensor at the ECM, KOEO it is 1.50v.
What I need to do now is figure out what the voltage should be.
I'm guessing here, but I tried (312.5-(-11.25))/5=kPa per volt=64.75, so at 1.5v it would be 97.125 kPa. That's close, but not quite it since atmospheric pressure at the time was 100.53 kPa.

[DWC]

Is this sitting with key on? Why does your TPS show 29 percent?

[Scourage]

Yes, key on engine off.
Not sure what the TPS should be honestly, so I couldn't tell you why outside of that was where my first tuner set it at or there is another issue.

[jimmyblue]

While I don't know the particulars of this sensor, it
seems "off" to me. Last I looked at MAP sensors the
curve was 0.5V zero, 4.5V full scale and a 2-bar
ought to read 2.5V, not 1.5V at 100kPa on a 2-bar
MAP.

Any chance you've got a 2.5 or 3-bar sensor by
mistake? They're out there.

[Scourage]

It is the ZR1 3 bar MAP sensor, 12592525.

[DWC]

Jimmy is correct and your TPS should be at 0 key on motor off. I have purcahsed a 2 bar MAP sensor that had the correct number only to find out it did not work correctly (Ebay purchase)

[tommytuner]

3 bar sensor should be about 1.5-1.6 koeo depending on altitude. tps is relative to a few variables, this car is dbw so throttle will open for startup. unless it's giving you issues I wouldn't stress over the % just now. you just need to set up the correct config for your map, or you may have the wires switched. try swapping A and C, leaving B alone?

[DSteck]

KOEO for the 12592525 is 1.78v when baro is 100kPa.

[Scourage]

Thanks for the help so far everyone, and especially having that voltage info!
So today I decided to reinstall the stock MAP sensor and revert the settings for the MAP back to stock. I connected the MAP sensor to it's original connector since the Whipple install includes an extension harness, I'm thinking maybe it could be it.
Nope, still reading 82 kPa.

[DSteck]

Where are you geographically? A customer of mine lives in Colorado, and barometric pressure where he is only gets to 77kPa.

[Scourage]

Denver area, 6K feet. Based on the conversion table I used I should still be close to 100 kPa, currently at 30.17 in.
Edit; actually 102.2 per Barometric Pressure Conversion Chart

[DSteck]

There is no way barometric pressure is 102kPa at 6000ft.

http://www.crh.noaa.gov/bou/include/...ct=webpres.txt

82kPa is about right.

[Scourage]

That is just excellent, thanks so much. I was reading and converting MSL pressure not station, huge difference.
MAP was correct and my boost PID subtracting 11.9 for current atmospheric pressure, reads 0.01 psi KOEO.

I have been chasing the wrong rabbit down the wrong hole the entire time.

Again thanks

[DSteck]

Sometimes things are so simple that we over complicate them. I'm guilty of that. Glad to help.