Guys with MAP clamp.

[Andrade08]

OK.......Now I have played with 5v source sensors before. When I used to test the supply and return signals I could put the ignition on the "key on" position and get a 5v reading from the return signal. My question is this. Why is it that I read guys are installing these clamps and then flooring it to set the max voltage to clamp? Can't you just turn the key on but do not start the car and then probe the ground and signal return and dial in the 3.5v that way? Just seems easier to me that driving around and pulling over every few pulls to turn the screw a little more. When you turn the key on the sensor return signal will have the full 5v running to the ECM. At least that is how every other MAP sensor I played with worked. I used them along with MAF WOT v & the LM-1 RPM converter kits to log vacuum signals to convert to a load.

 

[Haltech]

No, your car needs to be under load just as if a real map sensor is being monitored.

 

[shucky]

No, it depends on which type of voltage clamp you have. A 3 wire like the dasmopar clamp laloosh has, needs to be set making WOT runs. No wires are cut with the 3 wire installs. A 4 wire unit, where the factory signal wire is cut can be set at rest with the ignition key in the "on" position. For reference I have a splitsec VC2-5 waiting to be installed, which is a 4 wire voltage clamp.

 

[Andrade08]

Ah I got ya. I have the 3 wire unit. I know I read all this stuff but I didn't remember why what was what.
Last thing floating in my head is...........The MAP still delivers the voltages BELOW the clamp right? Or is it that the voltage is clamped at 3.5v constant?
Like if I am at part throttle and the MAP is sending out a 2.5v signal......that still gets to the ECM right? The clmamp is just there to set a max voltage signal to the ECM?

 

[driver311]

Mines a 4 wire and you can set it with the key in the on position. works sweet with a test wire and all. PTP map clamp. You have to splice for this one. EASY!

 

[Bravnik]

It sends a signal up to your clamped voltage then stops there. I used my DashHawk to clamp mine and I clamped it a little over 10PSI. I found that if you clamped higher you got more stutter.

 

[mitchellmtch]

hey 311 where did you purchase your map clamp from