Boost leak test question + Mileage

[Prodigyman]

So I got a third DSM (215 000KM/128 000 Miles 95 TSI AWD with nice snows) for winter/spring beater while my GSX is getting ready in the shop(Fully built 6Bolt stroker, FP3065 etc etc...). So this DSM being DSM I fixed tons of things on it using stock spare parts off the GSX and now I got to the boost leak test...

Car as 1G BOV and metal UICP (to the last bend and then its stock) rest is stock rubber. Turbo to TB no leaks at all (changed TB(from GSX) and both gaskets too). Now I hooked up my tester to the TB and pushed about 15 PSI on 3GL compressor through it. Boost gauge registered about 9 PSI and died off to 0 in about 4-7 seconds, air sound was coming from intake runners area (sounds like mani gasket but I doubt it)

My question is don't you have to crank the engine certain way so air doesn't leak through the head back to exhaust, if so what is the proper way of doing it so I can pressurize the intake manifold properly?

Car runs retarded rich (even with new 6'sNKG plugs, NKG wires, new Denso O2, new(Front AND rear) new stock Rad n coolant, GSX working TB+new gaskets , 60k T25 and all gaskets, Fresh 10W30 Mobile 1 Synthetic with Lucas + OEM Mitsu filter, new DeJon intake and K&N Filter and fixed ALL exhaust leaks). Mileage is about 200 KM a tank (~124 miles) on Sunoco 94. So I tired evething and I am LOST, why is this DSM consuming retarded amount of gas, I mean my GSX when it had HUGE boost leaks and leaky injector gave me 230 miles a tank and i was not babying it ether...

Took off OLD MBC (Spring type) and directly connected from Turbo to WG so its solid 12 PSI with no creep @ ~ 2800 RPM, Idle VAC 11-16 in/hg.

 

[xveganxcowboyx]

Check your lower injector seals. They harden over time and can leak. They are ~$10 at the dealer so it's probably good to just replace them. Use soapy water in a spray bottle so you can see the leaks clearly.

 

[winterftbl]

To do a proper boost leak test you are suppose to be at tdc with the number one cylinder.

 

[kenamond]

To do a proper boost leak test you are suppose to be at tdc with the number one cylinder.

I don't think this is correct. You want 30°ATDC to dodge valve overlap (which occurs at TDC). But I've NEVER had a problem on my 2g with valve overlap during a BLT. He wouldn't build any pressure in that case.

I agree with vegancowboy about injector insulators and testing them by spraying them with super-soapy water. Stuff your head deep under the hood, spray where the injectors meet the head, then pressurize. They'll probably foam up. It's pretty easy to change the insulators, and there's a tech articles on this forum that points out some of the gotchas.

 

[Prodigyman]

Thx for suggestions guys. I'll try to crank the engine to the right position and see where it goes. I am getting Evo IIIX injections but thats few month form now so I can't spend 50-60 bux every 3 days on gas and prob have to fix 450s first. I wouldn't think Leaking injectors seals would cause such horrible gas mileage.

I know my fuel filter prob never got changed since 1995 so I'll change that tomorrow once dealership has it so hopefully that'll improve the mileage after all...

 

[xveganxcowboyx]

The new injector seals will swap over to the evo VIII injectors. They are the same.