I recently installed a brand new GReddy electronic boost gauge. It reads boost just fine, but it always reads 0 vac, even after throttle release after boost, it goes straight to 0, never lower.

I installed the provided GReddy boost sensor and "T"d it with the BOV vac line and into the UIM on one of the nipples under the throttle cable linkage. Would that affect vac readings? I have read some people "T" the sensors to FPR's and others to the stock boost sensor going to the nipple on the ACV or the nipple under the BAC if the ACV is removed...

some quick things... i have all emissions removed, just replaced all vac lines with brand new silicone ones, new manifold gasket. Idles at 750-800 (slightly fluctuates between 750-800) i dont think i have a vac leak...

 

Try connecting it to one of the nipple on the front near the alternator on the TB. If that doesnt work, does the boost gauge support reading vacuum?

You can also tee it to the map vac line on side of the LIM

 

Not all the nipples will read Vac/boost.
I found that out hooking up my Boost controller.I had no vacuum reading what so ever.
Do as Knight says and T it into the Map Vac line.

 

Thanks for your help guys, i Td into the map vac line and works perfect now. reads roughly -20 mmhg at idle.

 

That has to be a typo. 20 mmhg is less than one inch of mercury.

 

if it is 20 inhg, thats a healthy engine lol

 

sorry it is 20inhg not mmhg Lol