Sometimes when I start my Evo up, the boost gauge sits at zero showing no vaccuum. Sometimes it's just for a few seconds, sometimes I have to drive for awhile for it to show the proper vaccuum. Do I have a leak somewhere or is this a normal thing with this particular gauge?

 

mine does that sometimes. I have a Apexi gauge though.
I dont think anything is wrong with the gauge.
i've heard that might happen depending on where the gauge is tapped to.

I am sure there is a fix for it.
any suggestions?

 

Where are you tapped into for a vacuum source?

 

i have it tapped to the fpr line by the fuel rail.

is there a different/better way to do it?
if so, please show me with pics.

thanks a bunch.

 

Okay.That is a good place. But...

It has to be tapped in between the fitting on the intake manifold and the Fuel Pressure Solenoid. NOT between the solenoid and the FPR. The solenoid will shut off vacuum to the FPR and then you will get no readings.

The vaccum port is right there by the FPR on the manifold. The T should be right on that hose. If it is on the hose coming directly off the FPR then that is a problem.

 

i just noticed it today. i installed my defi over the weekend, and never had issuess with this till today i noticed when i came from lunch it was stuck at 0, unless i started boostingn it raise up. than if i gave it a strong boost it would go back to vacumm at idle... could it be due to heat ?? ..odd question but only thing that i noticed differennt.

i did my install exactly like thiss.

https://www.evolutionm.net/features/...rojectevo/24/3

 

He is unclear in that install as to where exactly to tap the hose.
If you have the T attached to the FPR then it needs to be moved to the vacuum fitting on the manifold.

 

i am not clear when you say move the T fitting to the right.

can you post a pic of how yours looks?

I have the t fitting like right above the FPR, about 3 inches from it.

thanks for your help.

 

Sure I'll just get the camera and run out and take a picture for you.

Oh btw here is the pic.

 

Oh, the solenoid you see mounted on the end of the intake is the fuel pressure solenoid. The other hose (not picture) goes to the FPR. You don't want to be in that hose, which you state above that you are.

 

thnx for the picture.
so, it needs to be tapped to the line with the black electric tape looking line?

 

I tapped it to the location you told me to and everything seems fine.
The needle doesnt get stuck at 0 anymore. But I am still getting only 17lbs of boost. must be the weather. its around 75 but really humid... oh well.

for those that dont know, its the little vacum hose ( the short one from the intake mani). I have it tapped there and the gauge responds instantly.

 

17lbs of boost seems normal

 

I had the same problem so I was advised to tap it into the hose coming from the BOV to the intake mainfold. So far no problems.