When you hook up an FCD to boost sensor, Is a stock boost gauge sopose to shut off? My stock boost gauge doesn't work now but aftermarket is showing around 7,8.5 pounds of boost when i put intake and fcd. By the way i got 88 t2. please reply. thanks

 

i'm not sure if its supposed to totally stop working...but on the directions i got with my Racing Beat FCD, it said the stock gauge will no longer climb as high as it used to with the FCD now installed.

i'm not sure if anyone has a correct answer. some people on here say that as soon as the FCD goes in the gauge stops working...others say it still works...

from personal experience...i installed my FCD last week and the stock gauge still works...but prob doesn't climb as high as it should. i really don't know exactly how much boost i'm running. even before i put in the FCD the gauge never made it up to the top. highest i think it got was a little over half...maybe that had something to do with the ported wastegate...not sure. but its fast enough for me so i guess thast what counts

 

The stock gauge is useless after a FCD has been installed. If it shows a reading at all, that reading is not correct after a certain point because the FCD is telling the computer the boost isnt higher than a certain psi (5.5 I believe) so it wont cut the fuel and leave you hanging.

 

My boost guage doesn't work anyway, so it wasn't a big loss

 

 

Don't make me smack you, pizza boy

 

You can smack me for a small donation to the "Tony needs a new engine fund"

 

I have 12 cents.

 

12 cents will buy you a chance to him me with a rock, roughly the size of a marble, while I stand 30 yards away. All arrangements to get here must be provided by you. Rock must be inspected by target before thrown for acceptance.

 

Can I use a slingshot?

 

You can use a slingshot that is roughly the size of the fork. The rubber band may be deemed "unacceptable" by the target if it looks too dangerous.

 

Back on topic (boy, these guys have no brain at all )

Your boost gauge SHOULD BE WORKING normally. All the FCD does is intercept the voltage measured by the boost sensor, and:
a) trasmit as it is if it's below the threshold
b) trim it to the max threshold, it it exceeds it
(the above circuit is called a peak-n-hold clamp)
Therefor the boost gauge should show exactly the same boost as before, only you can start boosting more without the gauge showing it (because the FCD will keep the max boost measurement constant). That's all...
So, if your gauge is not reading boost properly, then maybe:
a) your gauge is busted
b) you are not reading boost at all, meaning that your ECU is not reading the boost as well (and thats bad ). Some wire was cut or disconnected. Check again your installation

 

yup mine reads the same as before...

 

my stock one guage doesn't want to show anything, but on my aftermarket phantom gauge it shows around 8psi. So i think it still works and it shows good, once I unhook FCD it starts working again.

 

If your gauge stops working when you disconnect the FCD, and then starts again when you install the FCD again, then either a connector or the FCD itself has a problem. Since the stock gauge reads the same voltage as the ECU, then if you are not reading anything in the stock gauge, then the ECU is also reading nothing

I could be wrong, but that's what happened to me the first couple of times I tried to install Paul Stoke's DIY FCD. Sometimes the gauge would read zero, sometimes it would shoot to the top (short-circuit), sometimes it would read only up to 0. Once I had all the connections right and soldered, everything was normal again. I would suggest taking the FCD and your car to an electronics guy (or where you bought it) and have them check it....