Cracked brake booster line cause boost leaks??

[h100vw]

I will get logs from my mechanic next week he can plug his scanner in for live logging but found this tuner from a guy on yt he has about 400.000km on his gti with all stock internals running the same tune hitting 20+ psi on the daily and so far he's done 15.000km and other people safely doing 80.000km so far on this tune with no dramas or issues. And for the price I couldn't complain even that it was a xmas gift from my wife plus all the mods done to get it to stage 2.

Doesnt mean that it is running correctly on yours though. Please keep off the gas until it's been logged and checked.

[Nikogti]

I don't think it is running well now cause I'm reading -5 now on vaccum and it was -20 this morning

[h100vw]

I don't think it is running well now cause I'm reading -5 now on vaccum and it was -20 this morning

definitely a leak there then

[sambb]

At idle - then that's got to be something coming off the plenum eg brake booster, PCV line, SAI lines, N249 diverter valve reservoir lines, the boost gauge vacuum line itself, the silly suction vacuum pump Y piece that goes into the brake line has a smaller line running to the TIP with a one way valve, injector cups can crack and injector O-rings perish. Could be torn hose, usually at the connection point, a 1 way valve stuck open, PCV hard plastic fitting into the block is cracked, dipstick tube cracked. Spray WD40 at all the connection points that lead to the plenum with the car idling/vacuuming. If something is open to atmosphere it'll suck the WD40 and flare the revs a bit.

[Nikogti]

Thanks guys I will look into it tomorrow and try the wd40 trick but on start up it's -10 and after a drive it sits at -2 to -5 on idle

[sambb]

yep should be on 20 in/hg

[Nikogti]

I moved around the silcone hose going from the boost gauge to the T piece and got it to read -18. Maybe I might have to expand the hole on the passenger side where i feed the hose through.

All I did was clean the maf plus put injector cleaner in and fixed that brake booster line with silcone tape. But just odd after unplugging the n75 2x its hitting 23psi always now. But couldn't get past 18psi before.

I ordered new ngk plugs A new maf and a new n75 valve they should arrive this week.
I Just can't wait for the smoke machine to arrive so I can go over it all. But next week I'll take it for live logging and want to do a power run on a dyno

[sambb]

Just occurred to me that it could also be the diverter valve itself. To test it remove it from the car with the vacuum line hose still attached. Push the plunger up (its spring loaded) while sucking on the vacuum line. When you release your finger, the plunger should stay put/float on the vacuum you are holding on the top side of the DV with the line that's in your mouth. If the plunger slams shut then the DV diaphragm is torn and it'll be bleeding off boost, maybe intermittently.

[Nikogti]

This is my 3rd dv in past 2 months the stock one broke open and then upgraded to a audi tt one & that blew up in a week and now have a 3 spring setting metal dv I've put the yellow spring in that's meant to hold 25psi and the red spring holds 15 to 20psi and the silver spring is for stock.. it did come with 2 metal spacers and unsure how that works anyway but put them on there and screwed it back togther.

Just changed the spark plugs to one step colder plugs and its sitting at -20 now
Plus my boost gauge I'm only getting 18psi all day today

[h100vw]

You know you need to have it loaded up, a boot in 2nd wont show the same pressure as a drag uphill in 4th.
A 3rd gear log from 1500 revs is what is needed as a test