Stock boost sending unit bad?

[Boostian]

Any way to test the MAP sensor other than just replacing it? I replaced the vacuum lines to it and I still have nothing on my dash showing up. Could it be a digital dash problem? Or is it the sensor?

My a pillar boost gauge works fine, the dash one is just because I'm anal and know it doesn't work.


From my iPhone

 

[earlbrown]

I've never heard of the MAP sensor going bad. Usually it's the plastic line or the rubber ends breaking. I've never had a digital dash so I can't get specific with the display. First I would make sure the MAP has + and - 5V. Then shoot pressure into it and watch the third wire. It should show the change in output.

If you want to take the easy way and just swap it out to see what happens, it's just a plain ole 2bar unit. Not a rare expensive turbo buick specific sensor.

 

[Boostian]

The two bar MAP that Caspers has is for analog dash only and it's not cheap ($73). I can only imagine what the digital one costs...

I have a working aftermarket gauge, so this isn't THAT important. If the sensor was $25 I'd just replace it, but $75 is dipping into my intercooler funds.....

From my iPhone

 

[aminga]

Digital dash doesn't have a MAP, only a hobbs switch that lights the lights at specific boost levels

 

[GNONYX]

X2
Highway Stars has this Hobbs switch
http://www.nos4gn.com/servlet/the-33/Buick-Grand-National-boost/Detail

 

[Boostian]

Digital dash doesn't have a MAP, only a hobbs switch that lights the lights at specific boost levels

That looks more like it. I looked at the picture of the MAP switch and thought I just overlooked it.

Appreciate the link. Won't be dropping $80 on that one either, but good for reference


From my iPhone

 

[GNONYX]

If your unit is bad or it may be out of adjustment you might want to be re-adjust it since it's not working properly.
See Casper's PDF
I replaced the Hobbs Switch and about a year the damn hobbs switch only display the low boost.
I do rely on the electric boost/Vac gauge, and even that I question since I tested it and found it to be off 3psi.
My next boost/Vac gauge is going to mechanical type.

 

[Boostian]

Thanks for the PDF. Ill take a look at it. I have a mechanical boost/vac gauge I use, it's teed into the vac line that goes to the Hobbs switch. But I have absolutely no display on the dash.

If I can fix it, cool. If not, like i said, not worth spending $80 just to see the display on the dash also (which isn't real accurate as it is)


From my iPhone

 

[earlbrown]

Hobbs switches are even easier to test. You can either put a meter on the posts and pressurize the switch and see if it changes state..... Or just short it out and see if a dash bulb lights up.