Not building Boost

[Iyaoyas]

I have tried everything i can think of and still no luck someone please help! I have a 95 GSX. I bought the car cheap cause it had a rod knocking. I rebuilt the engine back to stock. new crank, pistons,rings, and bearings. I only replaced the 1 bad rod. I have a 20 turbo, full turbo back exhaust, manuel boost controller, Turbo timer, front mount intercooler. My problem is when i start the car my boost gauge goes to around -20 vacuum (not sure what the unit of measure is if its psi or what) when i hit the throttle my gauge will jump up to around 0 and then fall back into vacuum. I can not built any boost. I have checked other threads that said "Waste gate" was the problem I took off the turbo and noticed it had a crack in the exhaust housing so changed to a T3/T4 turbo. Still didnt fix my problem. I have removed the egr valve and installed a block off plate, I have removed all my vacuum lines and only hooked up a vacuum line to my fuel pressure regulator and "T" to my boost/vacuum gauge and to my BOV, i did not hook up my wastegate thinking that maybe it is opening and letting all the presure out. I have changed intake's (to another stock one) the one that came on the car had nos ports. I used a Halloween smoke machine to try and check for leaks ( dont do this it is a REALLY bad idea ).
I dont know what else it could be, if anyone has any ideas please let me know thank you for your help

 

[dral24]

have you done a boost leak test? best idea would be to get a threaded pvc and a cap drill a hole for a tire valve seal it all up nice and get a coupler and clamp it directly to the compressor housing on the turbo while the car is off and get a bike pump and pump it listening for leaks and its best to have someone in your car reading off the boost gauge to make sure you do not over boost your car

https://lh3.googleusercontent.com/_vrFAhYxNh34/TcaNuVJvM_I/AAAAAAAAAOE/NpuUxleDVHU/s720/IMG_0300.JPG

 

[LiquidX]

You need to perform a proper boost leak test, testing to 20 psi and spraying soapy water to look for bubbles. Start at the TB elbow and fix all the leaks. After that move to the compressor inlet. You should hold pressure for at least a minute depending on how well your internals seal and if you have open valves or not.

A good way to check for pre turbine leaks is by running skmr SeaFoam since it will smoke when it's ran through the system. It will not show a bad wastegate however.

Do a search for boost leak testing and you will get the desired information.

 

[Iyaoyas]

Did a boost leakdown test and after putting 30 psi into the system the gauge only reads aroud 5 psi. took the soap and water and found that there are alot of leaks. My fuel injectors(at the head) are leaking, my throttle body gaskets and idle air screw are leaking, and i have a pin hole in my intercooling piping. So far those are the only leaks i have found.
Going to buy a new 62mm BBK throttle body, intall my new 850cc injectors, and try and patch the pin hole. I have to wait to see if the car is building boost until my computer gets back. I bought DSMlink and my ecu is getting socketed. Thank you all for your help and advise will keep you informend of progress

 

[dral24]

good luck man im sure that'll fix ## problems for the most part

 

[dsmkight]

you wont build any boost sitting still or while your in neutral, unless... you are runing anti-lag when u get dsmlink

 

[Thugmaster1220]

Just wait till you fix those problems and unleash all that wasted power

 

[Iyaoyas]

why do you say wasted power?

 

[eatsleepboostin]

I agree. Only boost leak test will solve your problem. Had same problem. No boost. Made a home made boost leak tester. Did the leak test, found the leak. Tighten the clamp and now, it's all good.
No more leak.