factory boost led guage

[DEMO MAN]

my factory boost led guage didn't work so while in BG i got a rebuilt one from caspers. i installed the new board tonight and it still don't work. tach works and did before replacement. these are known to go bad so i thought that was it but obviously not! what else controls this? i have a 3 bar map installed for alky. anyone know what could be wrong? thanks, tim

 

[Fuelie600]

On the pass inner fender, sits a MAP sensor. It is mounted just in front of the blower/AC housing. There is a hard plastic line going to it from the engine. This MAP, or related lines and plug are most likely the culprit.

 

[DEMO MAN]

thanks fuelie, my stock was just replaced with a 3 bar and i don't believe it worked with the oem one. i'll look into the plugs and lines tomorrow. that piece was a real b#tch to change and when it didn't work i was just disgusted, especially after driven back 8 hrs from BG after the horrible weather there.
thanks, tim

 

[Tony Shoaff]

Bad factory gauge unit! It happens.

 

[aminga]

thanks fuelie, my stock was just replaced with a 3 bar and i don't believe it worked with the oem one. i'll look into the plugs and lines tomorrow. that piece was a real b#tch to change and when it didn't work i was just disgusted, especially after driven back 8 hrs from BG after the horrible weather there.
thanks, tim

So you have a stock boost gauge and you replaced the factory MAP sensor with a 3 bar.

Or do you have 2 MAP sensors. One factory 2bar and one 3bar for the akly kit.

If it's the first case it probably won't read. You've changed the scaling of the gauge. Now 2.5 volts where the gauge starts to read is really 7 PSI and 5 volts (what the gauge sees as 15 PSI) is now 30 PSI.

 

[Turbo1dr]

So far I've bought 2 tachs from Caspers and both works perfect. Something else must be wrong in your wiring or MAP. Be sure the terminals are properly inserted in all the connectors.

 

[DEMO MAN]

guys, thanks alot for your help. it's working now, apparently you have to be driving the car for it to register . last night when i installed it i tried to check it by power braking it. my mechanical guage was going up to atleast 5 and nothing on the led so i thought i had a problem. today i went for a ride and it worked fine .
once again, thanks alot. tim