No boost, 87 turbo, new turbo
 

Just put on a rebuilt turbo (stock ht 18 with upgradedwheels all new internalls) from Majestic turbo.
Problem is I have no boost pressure. The turbo wheel spins free, no rubbing or play. Oil flow to the turbo was ok. Checked hoses and vac lines and appeared to be ok. Wastegate valve works. Turbo controll switching actuator works. Can,t find any leaks or blow by from lines. Turbo control system solenoide valve works.

When i go from idle to 4000/5000 rpm the trubo spools up then sounds like if spools down even before letting off gas. Kind of whines as it spools up and down.
I put a pressure guage on the bypass hose of the stock intercooler and get no boost pressure when I take it to 5-6000 rpm. The stock boost gauge moves up to less than 0 for a second then drops back.
Have a racing beat exhaust and no cats, fuel cut defensor, and cone filter, everything elese stock. Car starts ok, no smoke or leaks from the turbo.
Any ideas what could be wrong?
Thanks

Sorry for the dumb question, but are you doing this when driving? You won't be making boost in neutral with no load on the motor.

true that, some people do but really I would be driving to make sure instead of just idling it. Good luck.

it kinda sounds like huh? thats what your boost gauge will do with no load on the motor. maybe you have a major leak in your piping?

No- drive the car around the block, boost guage just sits there, even floored. Acts like an normal 13 b without a turbo.

you sure theres no leaks in the piping?

Haven,t been able to find any, hose to throttle body and intercoller, hose to intercoller to turbo tight. I tested the boost sensor- it reads around 2 volts and should be 3.5 to 4.5 and 3.9 hg., but i dont think this would create a no boost problem, or would it?

You have to drive the car under a LOAD to get boost. Try forth gear, up a grade, at 2000 to 5000 rpm and then tell us the turbo won't boost.

I used to have a no boost problem with my fc the main things that helped that out was

a) new turbo (doesn't apply in your case)
b) changed out my ghetto front mount to stock top mounted intercooler and made sure there was no bad clamps, this made me boost to about 5 psi
c) the last thing was doing the fuel pump rewire. after I did this I started getting full boost.

Don't know if any of these will help but good luck.

What was the fuel pump rewire deal? I have a upgraded fuel pump- pumps more than stock.
Took the car out on the open road, am getting boost now- stock boost guage behaving differant than with the stock turbo, reads lower now.
Do ahve a minor vac leak in the hose to the boost sensor and the sensor is reading 2 volts when it should read 4.5volts. When I first started up the engine with the new turbo it smoked like crazy- around the turbo- thought I burnt it up- must have been oil on the outside of the housing.

You should have around ~0.003" play on your turbo (Look up the spec for endplay). If you have none and it heats up it's just going to seeze..You may be able to still run the engine but i dought any higher than 2 or 3000RPM. How come people keep saying "no play" when indeed specs say it should have some play?

I would start looking at your minor vac leak and going from there. No use jumping around something if it needs to be fixed anyhow.

If it's a rebuilt turbo lets start looking at the wastegate, and intake line running off the compressor.

When I put the rebuilt turbo in the end play was 0, now that I have run it about 20 min it has a little end play and turns very easy.
Put a pressure test of 10 psi on the line to the waste gate and it operates ok and holds pressure.

Have you confirmed that the wastegate is, in fact, closed while the car is not building boost?If its stuck open, even slightly, it will never build boost.

get a real boost gauge.