waste gate experts please

[9dreizig]

Originally Posted by NathanUK

Did you try blocking off the muffler first?

No but I've re-assembled and am resonably confident it wasn't the problem .. a bit embarrassing here but the pic I took was without the seperate flange,, when that is added and is tightened down ( when installed) that it is sealed.. Sooo back to the original non-boost issue..

I am able to get 0.4 bar out of it BUT it's black smoke and breaking up, pig rich.. so I"m back to chasing a vacuum leak somewhere I suspect..
Todd

[RarlyL8]

black smoke and breaking up, pig rich

This is very telling. You are either getting too much gas, not enough spark or not enough air which is drowning the plugs.

[9dreizig]

Originally Posted by RarlyL8

This is very telling. You are either getting too much gas, not enough spark or not enough air which is drowning the plugs.

Bryan, I've checked the fuel pressure and WUR and it's fine.. I'm thinking vacuum leak somewhere.. How would I check the integrity of the spark ?? It fires right up and idles fine.
Here's another bit of info.. there's some oil around the bottom of the turbo,, not sure where it's coming from .. Could it be the turbo causing these problems ??
Todd

[beepbeep]

Dude, you have a boost leak. Everyone was telling you that from the start but you were out blaming wastegate

You turbo draws in lot's of air but it then leaks out. But fuel gets injected. That's why it goes rich. Leak this big easily overspeed the turbo as well, so you better find it quick.

Check you intercooler O-rings and phenolic intake spacers for cracks.

[rsrmike]

Originally Posted by beepbeep

Wastegate valve must be very leaky in order to significantly affect boost. I'm not sur that little leak on picture is enough.

I believe your main problem is leak somewhere between engine and turbo. Intercooler O-rings, phenolic intake spacers etc.

Originally Posted by 9dreizig

Bryan, I've checked the fuel pressure and WUR and it's fine.. I'm thinking vacuum leak somewhere.. How would I check the integrity of the spark ?? It fires right up and idles fine.
Here's another bit of info.. there's some oil around the bottom of the turbo,, not sure where it's coming from .. Could it be the turbo causing these problems ??
Todd

Originally Posted by beepbeep

Dude, you have a boost leak. Everyone was telling you that from the start but you were out blaming wastegate

You turbo draws in lot's of air but it then leaks out. But fuel gets injected. That's why it goes rich. Leak this big easily overspeed the turbo as well, so you better find it quick.

Check you intercooler O-rings and phenolic intake spacers for cracks.

Don't forget to lift off the metal up-pipe from turbo to intercooler and check that o-ring (I'm sure Goran means that one too, just helping to spell it out: b-o-o-s-t-l-e-a-k

Perhaps your boost leak, oil leak, and pending death of your turbocharger will be right there. Good luck

[voitureltd]

I used to have this problem on a 930 with a Andial intercooler. The stock pipe is modified to fit the intercooler and uses a blue intercooler high pressure hose that is clamped to the original solid pipe. Put in a new seal between the pipe to intercooler. Then drill and tap a hole in the pipe for the installation of a set screw. Under high boost the pipe can move down and the red o ring seal can bulge out ( usually in the back where you can't easily see the bulge )and create a pressure loss.

[rsrmike]

Don't forget the o-ring at the bottom,
It's where the blue hose is on the picture above.

If you have access to compressed air, you should rig up an intake leak tester...

[Tt surgeon]

Read this old thread, I'm having a similar problem.
Recently did the k27, primed on install, etc. First week, pulled strong. Now pulls 1.0 bar but the power is way down.
Could the wg diaphram be shot? Turbo shot already(not primed enough)?
tia
c

[9dreizig]

Tt, with mine it turned out to be the intake had a number of loose nuts holding it down, so the leaks were multiple ..

[TT Gasman]

Make sure your stock wastegate is rebuildable, mine had a crack in the body, among other things. I pulled the trigger on a Tial, couldn't be happier. The stock WG is a good piece but it's also 25+ years old with lots of heat cycles.

[Ronnie's.930]

Originally Posted by TT Gasman

Make sure your stock wastegate is rebuildable, mine had a crack in the body, among other things. I pulled the trigger on a Tial, couldn't be happier. The stock WG is a good piece but it's also 25+ years old with lots of heat cycles.

This is a good point and really, the stock wastegate should be taken apart and checked before new parts are bought. The "lip" on the body, bell housing side, that holds the diaphram in position, on mine, was corroded away about half way around . . . somewhat of a threadjack, I guess.

[Tt surgeon]

Good point. I'm gonna pull off the WG and look it over tonight.
I assume if I didn't prime the new k 27 enough and it was seizing, there would be other symptoms?
Just thinking of all the possibilities.
c

[Ronnie's.930]

There really is no such thing as "priming" the turbo other than making sure oil is flowing through it before initial startup . . . also, if the turbo was seizing, you would hear hellacious noise coming from it (screeching/howling and the like), and the overheated seals would be throwing oil.

[Tt surgeon]

Makes sense. Thanx
Do you think my issue could be WG related given the fact it hits full boost?
tia
c

[Ronnie's.930]

I'm not sure about that . . . I believe that if the diaphram was torn you would overboost and if the valve guide was leaking too much air you would not get enough boost. Hopefully someone with more knowledge than I have will chime in.

[RarlyL8]

Now pulls 1.0 bar but the power is way down.

If it pulls and holds 1bar the wastegate is doing it's job. It's springtime are you getting heat soak? That can cost you 50 horse. If not check your state of tune.

[Tt surgeon]

I don't think it's heat soak, I have a big Andial IC and it's cool to touch all the time.
If the wg diaphram is torn wouldn't it still boost but leak like crazy/losing hp?

[gsxrken]

Torn diaphragm would allow you to over boost.
As said, if your turbo can make and your waste gate can maintain 1 bar, you have other issues.
WUR pressures or maybe distributor is not advancing?

[Tt surgeon]

hard to tell if it's over boosting w the stock gauge pegged at 1 bar, I checked everything except the wg so far.

[gsxrken]

But if it was overboosting, you wouldn't be complaining about low power.
And theoretically, your overboost kill switch would eventually go off, and you would know when it did because the car would fall on it's face.
I have a WG you can borrow.