Chuck Henry

If I clamp the line to the wastegate, it shouldn't open if it's closed.
If the pipes are clear, exhaust will get to the turbo.
If the turbo spins freely, smooth, and looks good it will create pressure.
If I pressure test the intake side and there is no leaks, I should make boost.

I pulled all of the exhaust off and could find no evidence of plugging. I checked both sides of the turbo and it looks good. I checked and the wastegate is closed when at rest. I had pressure tested the intake and could find no leaks.

So at this point, I am leaning towards the following: (in order)
There is something wrong with the gauge
The wastegate is opening even when clamped
The turbo isn't working for some reason even though it seems fine

The one thing I did find wrong was the small hard-line that comes up from the top of the flat part of the crossover is broken off. What is this for and where is it supposed to go?

Any ideas? I'm planning to put it back together and install a manual boost controller to eliminate the factory valve and put in a dedicated boost gauge. Then test again and if I still don't have any boost I'll change out the wastegate. If that doesn't work, well, on to the turbo I guess.

mahoney944

The aftermarket boost gauge is a good idea. I'd say you got a good plan of attack

Chuck Henry

I'm also ordering a bunch of stuff that's easier to do while it's apart. While at the moment I can't control anything, an 02 gauge would be good to install while I'm in there and a full tune up/fuel/air filters just to rule as much out as I can and give me a better baseline. At least it will run well as a non-turbo then. ;-)

Tom M'Guinn

That tube on the cross over pipe needs to be capped shut. Otherwise, it will leak plenty of exhaust and act just like a small open wastegate. It was originally used as a test port to check the air/fuel mixture, but is more often used these days as an EGT sensor port, or to check back pressure in front of the turbo.

Chuck Henry

Yep, I'll cap that off before putting it back together. After talking to some people, I really think it IS making boost. It drove a little too well for it to not be, especially at this altitude.

With the manual boost controller, what PSI should I be looking for on a stock car at about 6000' in elevation?

mahoney944

If the car is boosting the klr or gauge is the issue. Or the klr line from the manifold

Chuck Henry

I checked the KLR line and it seems fine. I won't REALLY know what it's doing until I get a boost gauge installed. Then I'll drive it and see what's what, but my guess is the gauge. I've ruled out the mechanical bits I believe, but only time will tell. I should have it together next week and I'll report.

Tom M'Guinn

What are your symptoms? What does the stock gauge say at idle, and with the motor off but ignition on? Should be around .4 at idle and around 1 with motor not running but ignition on.

docwyte

It's really obvious when the car makes boost. With that turbo it comes on with a very strong hit...

Chuck Henry

I'll check next time it's running. I want to say it was around .4 at idle or less. I think it would be around .7 or so and come up to 1 pretty quick when I got on it.

Nope, certainly doesn't do that. So probably still have something wrong. Maybe the wastegate. That will be my next stop of what I'm doing doesn't make a change.

Willard Bridgham 3

The exhaust also has to get away from the turbo. Did you check for downpipe collapse? Have you checked the cat for plugging?

Chuck Henry

Yep, pulled all the exhaust including the crossover off and all was clear. That was my first suspicion.

mahoney944

Aright. If you're making exhaust, it's flowing properly and your turbo play is normal, the turbo is making boost most likely. So somewhere from the turbo to the head it has to be leaking if you don't see boost. Assuming the head gasket is OK. So parts list to check:

Turbo to hard pipe hose
Line to wastegate using MBC
Wastegate diaphragm
Hard pipe to intercooler hose
The intercooler leak test
Intercooler to hard pipe hose (manifold side)
Bypass valve and connections
Isv hoses (venturi delete)
All vac hoses and fittings
Hard pipe to intake hose
Throttle body gasket
Intake manifold seals
Intake / exhaust valves in the head
Head gasket
Cylinder compression check

Chuck Henry

That's a good check list. I had checked most of that before, but I will run down it again once I get things back together. I ordered some stuff including IC boots just because they weren't in the best shape. Having a good gauge in there will be helpful too so I can confirm what it is (or isn't) doing.

TurboTommy

So, are you saying that when you floor it, your stock boost gauge only goes to 1?
Actually, the stock gauge is an absolute pressure reading; so 1 bar absolute would actually be probably about 3 psi boost at high elevation. Not getting more than 3 psi boost means you're in limp mode, which is often an electrical issue. Could be your cycling valve, TPS sensor, knock sensor, or KLR, comes to mind. This means your turbo and exhaust are probably fine; and if you had such a boost leak as to not making any positive pressure, it would run terribly rich (which would be very obvious).
And, contrary to what you hear alot, the stock wastegate and stock boost gauge are actually very reliable (they just don't serve well when doing more extensive mods).
That's my guess; limp mode.
If you did install an aftermarket boost gauge it would probably read 3 psi boost when your stock gauge reads "1" (on account of the high elevation)