# Which line to tap into for boost gauge?



## votblindub (May 1, 2008)

I hooked up my new boost gauge in the car, but I dont think it's hooked up to the right line. I was told to use the line between the two diverter valves on my 2.7T, but it doesnt seem like its getting a correct reading off that line. It shows 20 vacuum when i cruise, which afaik is correct, but when i get on it, it crawls up a bit and hovers around 5-10 vacuum. sometimes it eeks up towards 0 and sits there a bit. at one point i was getting 3-4psi on it, then 5, then it stayed at 0, then i was in 5th and got on it somewhat and it spiked to 15+ real fast and dropped right back down. so im thinking its not the line it should be hooked up to. i should mention im using a defi gauge. the line goes to a little black box which is a sensor and that just has a wire running to the gauge. i ran the line so its not pinched anywhere, so its making big round C shaped corners vs being taught. i ziptied all the points where the line connects to a fitting(t fitting and sensor), so i doubt theres leaks in it, but ill have somebody rev it and check those connections with a stethoscope. when i just turn the key to on the gauge goes thru a normal start up sequesnce and plants the needle at 0. when i start the car, it drops to 20 vacuum. i guess thats normal as well. so, which line to go to? theres like 45 different lines on my engine, some are metal, so obv not those. in the instructions it says to use the fuel pressure regulator line, but idk if i should. if i starve that line of vacuum or something at some point itll throw hella codes and make the car run like ass, unless thats what every's got done to theirs? help me out here, guys. thanks!
in return video
http://s334.photobucket.com/al...e.flv




_Modified by votblindub at 6:52 PM 10/13/2008_


----------



## 2035cc16v (May 18, 2000)

*Re: Which line to tap into for boost gauge? (votblindub)*

FPR


----------



## gtsindicate (Apr 27, 2006)

*Re: Which line to tap into for boost gauge? (2035cc16v)*

tap into vac hose behind intake manifold


----------

