LsTurbo91

Has anyone measured there 3 bar map sensor, with the ignition on? Measurement should be 1.64v or atmospheric, I'm getting 1.50v. I started logging with my Techedge 2.0 wideband unit. It has been measured with a multimeter as well. I also tried a BRAND spanking new 3bar map sensor with the same results.

Boost gauge/avcr will read 9-10lbs while my map sensor will be putting out 4-6lbs. That's going to be a problem. As of right now I'm changing it how I see in the logs through the zdyne and it is a lot more responsive, in terms of pinpointing the actual column.

Here's a test run I did last night: As you can see max boost is about 2.38v which is about 6lbs. Avcr/Autometer boost gauge, reading about the same 8-9lbs.



Here's the boost chart I made in reference to voltage-lb value. Using 10kpa=.164v

SiR Kid

I've never even thought about my MAP sensor being a problem... I jsut assumbed... Assumptions are bad, m'kay!

Trip to Radio Shack to get a voltmeter soon, I guess.

Mr. Softee

i had thought the whole function of the 3 bar map sensor was to divide voltage so you can run more boost. like if you are boosting 14.7psi + 14.7psi atmospheric, it tells the ecu you are running 29.4psi * 1.7/3

the 1.7/3 is from the 1.7bar stock map sensor / 3 bar map sensor.

maybe im wrong but this is what I had thought. or at least something along these lines.

sam

QHP

My theory is the MAP Voltage readout differs when the engine is running compare to the value you get with just the ignition ON. Try to add an offset of 0.18V to the voltage values of the Techedge unit and the boost reading should be about the same with your gauge.

LsTurbo91

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by QHP &raquo;</TD></TR><TR><TD CLASS="quote">My theory is the MAP Voltage readout differs when the engine is running compare to the value you get with just the ignition ON. Try to add an offset of 0.18V to the voltage values of the Techedge unit and the boost reading should be about the same with your gauge.</TD></TR></TABLE>

Yea, I tested all that out as well. Like I said earlier, either with the ignition on or "atmospheric", I get about 1.50v. That's with the engine running on 0vac. I also stated that I tested it with a voltmeter, as well as with different ground points with the same results.

I eliminated the techedge because,

1. Voltemeter had the same voltage
2. The fuel map was quite responsive in the area where voltage was given.

I always thought it was a bit off so I highlighted near by columns before I started logging the map sensor, but I didn't know it was this much off.