Map Sensor Problems????
 

My MAP sensor reads 1.20 bars on my commander. The map sensor should <b>always</b>have 5V going into it correct? I have this going into the map sensor. The output of the map is sensor is what should vary depening on the intake manifold pressure as I understand it.

My problem is intermittent. I drove my car 20 miles the other day and it ran like a champ. Parked it in the garage, came out the next day to take a long cruise and it would not start. The next day I tried starting it for the hell of it and it fired right up, I walked away and it died. Checked the commander and it read 1.2 bars. I verified 5V going into the sensor but I did not verify the return values at the PFC (was a bit lazy and had to push car around garage to get to PFC in kick panel). So, with this in mind, I am assumed I could possibly have a bad Map sensor which I hear is extremely rare. I do not have a bad sensor as I bought another one and got the same readings.

I jiggled wires to the ECU and check some of my grounds. Any further advice that may help me is appreciated.

I'm confused, are you converting millimeters of mercury the commander displays to bar? So the commander is displaying 900 mmhg when the engine is off?


Paul

Alittle confused, but yeh, Its 5volts in and 0-5v out. Do you have the correct map sensor? Stock one is only good for 14.5 PSI. My friend had a wiring short SOMEWHERE and blew like 8 map sensors. OUCH$$$$$$$$ I know expert but something doesn't sound right. You might have a short or wiring issue causing these high readings.

I guess it may be a bit confusing.......the PFC is reading +1.2 mmgh of pressure without the car running. This means that the map sensor thinks I have 16lbs of boost running through it. With the sensor unplugged, it reads +1.13 mmgh. I do not plan to run more than 12 - 14 lbs of boost when break in is completed.

Help!

Jeeezz......I am surprised no one has any input on this problem. I need to get this fixed so I can go to Rotorfest!

What problem?
You last stated that the MAP sensor was off by only 1 mm Hg (assuming your "mmgh" meant mm Hg).

edit: If you're saying that you think 1.2 mm Hg is the same as 16 PSI, you need to check your math. It's more like 0.02 PSI.
Reread the 2nd post.

Very good....It was a typo

Well, what I know is that the MAP sensor is supposed to read -500 ish "mm Hg" when the car is off. I was told by the RX7 store that 1.2 equates to 16lbs of boost and this is what it reads when the car is not running with just the ignition on. Regardless, the car will not start because of this.

I am just wondering if someone has some insight into what I might do to resolve this problem?

I may have confused you now. The monitor does display in bar when in boost, are you saying that's what you seeing when the car is off?

What screen are you reading these numbers? The monitor screen reads in mmHg in vacuum. But the sensor check displays in volts. Is that what your reading? The monitor setting should display 0 mmHg with the car off, but becouse the PFC is inaccurate reads about -30mmHg. Around -500mmHg is what you sould see at idle.

You might try posting in the PFC section.

Paul