Apex944

iTrader: (10)

Yes, I have searched and searched and searched and searched....
Im tired of running around in circles.

Ok, my 1988 T2 finally has a rebuilt turbo on it and its running.

But the boost/vac gauge i have on it says it is getting 0 vacuum at idle.

Compression on the front rotor is a little over 25 psi at all the bounces.
Rear rotor is 30ish psi at all the bounces.
Between 90ish and 100 psi total on the front.
A little over 100 psi total on the rear.

It starts right up, and runs strong.

But if I had 0 vacuum at idle, wouldnt the car not idle and die?
If so, could my boost/vac gauge be faulty?
It reads boost fine up to about 5.5 psi which is max for my T2.

Now, i also have ALOT of oil going into my tmic.
Its new oil for sure.
Ive searched and read that it could be caused by the crank case ventilation system. And that I can install a 1 way pcv valve and oil catch can to fix this.

Could this be because of 0 vacuum?
Because it sucks in and burns oil under boost.

Im going to do a vacuum leak test tomorrow using a write up I found.
So we'll see if it's got a vacuum leak.

After the leak test, im going to set my idle via FSM along with my timing.
And test as many sensor's and replace as many hoses that I can as well.

Any other helpful idea's or things i should do would be greatly appreciated.

walken

iTrader: (6)

you might have your boost gauge hooked to a pos pressure nipple. T it to your pressure sensor or the front lower nipple of your throttle body

Apex944

iTrader: (10)

I have it T'd into the boost pressure sensor line.
Could too long of a line be a problem?

gear_grinder

iTrader: (4)

my boost gauge reads 0 vac under idle, and my 87 TII runs fine. i have mine in the intercooler piping so its infront of the butterflys

HAILERS

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Then your boost pressure line is also connected up to a source that senses pressure before the throttle plates.

Not all nipples on the throttle body are sourced AFTER the throttle plates. Most on the series four are sourced prior to the throttle plates.

If you have a blockoff plated over the ACV hole, then install a nipple in the block off plate in the same location that the nipple on the ACV supplied vacuum/pressure. Although if you THINK about it, there are actually three places on the ACV blockoff plate where you can install a nipple to supply vacuum/pressure to the boost gauge/pressure sensor.

If your feeding off a installed ACV, at the original nipple that supplied vacuum/pressure to the boost sensor...............I've no idea why your car is screwed up.

Apex944

iTrader: (10)

Yep, its feeding off of the ACV nipple like the FSM says it should be.
Off to autozone and home depot then still.

Apex944

iTrader: (10)

Well, I havent done the leak test yet.
I found that there is ALOT of oil in the turbo compressor housing. Like pooled in the bottom of it.

There's no oil residue on the intake part where the TID bolts to.
But there is oil in the TID, bypass valve, and the other hoses that it connects to.
The oil was being pushed into the TMIC as well.

Could this mean a bad seal inside the turbo?
Or is it still because its sucking oil from one of the hoses in the TID even though there isnt any residue on the inlet to the turbo?

Well, im gonna clean out as much as I can.
Then hook up the PCV valve and oil catch can.
And see if it sucks anymore oil in....

HAILERS

Just remove the small hose with the silver checkvalve from the duct. Then remove the silver check valve from the small hose and reinstall the checkvalve back into the duct. Leave the small hose that held the checkvalve open to atmosphere. It hurts nothing to do that.

Now there can be no doubt where the oil comes from. If you wipe the duct clean of oil and anywhere else you see oil, then go for a long drive using boost etc. When you finish the drive just take the duct out and look for the oil. IF there's oil then it's the turbo seal imho.

You have the boost gauge hose coming off the ACV? The nipple that sticks straight out towards the fender? and there is no vacuum. Real hard to believe. I mean the engine would have to be almost useless. Try removing that hose at idle and feel the nipple for suction. It has to be there. If not, then the gasket is covering the hole. The other nipples on the acv are not sources of engine vacuum/boost. The one on the very bottom receives positive air from the relief solenoid and the one in the middle/fwd put's out air from the airpump to the relief solenoid. The one that sticks straight up on top receives vacuum from the switching solnenoid. Only the one that is at the very top of the ACV and sticks straight out towards the fender puts out vacuum/boost pressure.

Apex944

iTrader: (10)

Thanks for the info Hailers

I just found this info that aaron posted a while back....

" Blow by is combustion gasses being forced past the piston rings (for crappy piston engines) into the crankcase, or forced past the side seals and oil seals (for proper rotary engines) into the crankcase. This can build unwanted pressure if the purge system is not working properly and can certainly cause internal turbo oil bypass. However this leak is internal to the turbo and will cause smoking out of the exhaust. "

Apex944

iTrader: (10)

Also, I just looked at the vacuum diagram again...
The line WAS hooked up wrong...The 3 metal lines next to the ACV had the middle one going to the middle nipple, which is where the boost/vac line is supposed to go.
Still going to install the PCV system and oil catch can and put it back together and run it.
Cant drive it though, it wont be drivable for a few more months.

HAILERS

Boost sensors vacuum hose goes to the nipple on the ACV that is located at the very top of the ACV and sticking straight out at the fender. That is the ONLY source of vacuum from a nipple on the turbo ACV. Just clarifying what I said above. Nothing more or less.

HAILERS

Just thinking about that...........seems if you took the oil filler cap off and went for a ride you could prove that idea one way or the other. I mean, cap off equals no backpressure in the pan? Yes.

Apex944

iTrader: (10)

Good idea
I'll do that once im done with the PCV valve and oil catch can hookup.

Im not "new" to cars, engines, etc... but rotary engines and their designs make me just stand there and look at them like
" how the f**k does that route and work???? "

Thanks again for the helpful info.

nu-rx7junkie

iTrader: (1)

hook up your boost vac line after the throttle body thats how mine is under the bac valve i removed something there and used thatm port reads 10-20 hg until i boost.