Is my map sensor busted?
 

During connection to haltech with my computer it reads 187 Kpa all the time, in ambient, under cranking vacuum, under pressure. It seems to be stuck, The voltage coming off the 'map' wire always reads the same. DO i need a new one? Damnit!

Sounds like a "floating" problem, which usually means a broken connection or a loose wire problem.


-Ted

Do you mean inside the sensor itself? We have removed the wires and tested the sensor independantly. And it has behaved consistently.

No change in resistance when applying pressure/vacuum?


-Ted

none :(

Looks like a bad sensor... :(


-Ted

Sounds broken

have someone watch the readin on the data display page while you fiddle with the plug on the sensor, i had my plug loose connection, it would all be going good them all of a sudden it would go hell rich, stop and be eternally flooded, load the data page and hello i have 29psi boost when the engine is not going, cranking or trying to idle, the plug was crappy, got another plug, problem solved

sounds like a wiring or vacuum hose problem. make sure there are no vacuum leaks and check all wiring even if it was done by Haltech. make sure all plugs have made good connections.

That is the problem that I have, except that I pulled the plug out and made a direct connection at it was still reading 187Kpa, tried adding 12psi controlled source and powered the sensor, and the wiper doesn't work. But I was able to drive the car down the street and back with it thinking I was on the second to last bar :) Took alot of skill heh. GOnna buy a new sensor I guess.

The sensor is a basic general motors sensor isnt it? Nothing really special right?

Yes, you got it.&nbsp It's just a mechanically connected variable resistor.&nbsp Even under no power, you should still see a change in resistance between the power and signal pins.


-Ted

Wrong.

A MAP sensor is not a variable resistor, it's a variable capacitor. To correctly identify a faulty MAP sensor, you need a multimeter capable of reading capacitance and a source of measured pressure/depression.

BK

BMEP Fuel & Tuning

I correct myself. . . . Ford MAP sensors produce a varying frequency, but I cannot confirm that the same is true on the GM MAP sensors. If anyone can find a credible source to indicate one way or another, please share.

BK

We measured the Haltech (GM) MAP sensor with no power connected...reading resistance.&nbsp It still changed.


-Ted

I need to correct myself, before this gets someone in trouble.

It looks like you need some kinda power to get the MAP sensor to change.&nbsp I tried this both with a stock FD3S MAP sensor and the Haltech (GM) 3-bar MAP sensor - both didn't do anything unplugged.

I think I got it somehow confused with the TPS... :P


-Ted

Sounds like your vacuum hose / source is plugged up .