tunafish

I was referred to this forum by the great RX-7 Carl. Here is the problem I have a 79 RX-7, about 20 years ago I installed a BAE Turbo Charger kit. The car ran like a bat out of hell that turbo would kick in and whoosh like a sling shot.
Through the years a slight stalling problem evolved into a constant stalling problem. Over the years it also started to smoke. So I took off turbo tied to clean it started smoking like a chimney sent it out and had it rebuilt the turbo is a ray-jay. Turbo comes back put it on, no more smoke but boost gauge did not show boost.
Now to present time I discovered vacuum leaks fixed them. I start car I look at my boost gauge it use to read 0 now it reads 11 lbs vacuum I wind it out it feels like it goes in to boost but I am not sure. Boost gauge goes from 11 lbs to 0 but does not show boost to the right side of gauge.
I contact were turbo was repaired they say if you give it a spin it should make at least one revolution it does but I remember the old turbo spinning like a fan when you would give a spin the repaired one a revaluation and half or two.
Next I disassemble the waste gate all looks fine it has a plate a spring and piston attached to a rubber gasket ho holes in gasket how do I check if the waste gate is operating correctly? If it were not would it blow the entire boost out the waste gate? I hope the team of the rotary performance forum can help.

Rx7carl

LOL, dont call me great dude.
Hey all you turbo guys, and no answers to help him?

es

Make sure all of the turbo outlet piping is tight. You can apply pressure to the waste gate actuator to verify that it opens. Mity vac turbo systems test pumps are handy for this kind of stuff.

Oh, & the wastegate doesn't vent boost, it routes exhaust gasses & pressure around the turbo reducing the turbo RPM & compressor pressure/flow.

tunafish

I have one of those mighty vacs and when you pump it shows nothing, so I rig up some fittings so it fits my air compressor soon as you start to let air in you hear the wastegate hissing I give more pressure the valve retracts whoosh out the pressure vents. So from what I have been researching my understanding is if the wastegate was not operating correctly it would stay closed and I should show boost and possibly overboost and blow up the engine or the turbo but the gauge goes from 12lbs vacuum to 0 but never shows boost. I did test the boost gauge with the mighty vac it shows vacuum and pressure and holds both. Years ago the gauge did show boost. I have to tell ya this **** is gittin old there seems to be no end to getting this car back in to tip top shape. Any help I appreciate CARL sorry about the great thing you can call me anything you want as long as I get this car tuned out!

Rx7carl

If its safe to do, can you lock the wastegate closed so you can see if you can get boost sitting in the driveway? Just to test it?

Icemastr

iTrader: (2)

The wastegate is closed when just sitting, it wont come on until you reach some boost.