Tedro951

One of the more experienced listers may have a better idea, but I think the WG clamp trick should have resulted in higher boost, even if there is a problem with the DME/KLR, but if you can find one to swap it'll only take a few minutes.

EJZero1

Changed the oil today and while she was up in the air I had a look around the wastegate area. Obviously nothing to see externally that would indicate a problem, but I took a small hammer and tapped around the wastegate as much as I could access it. Finished the oil change and for whatever reason, decided to clamp off the CV to WG line again and took her out for a quick spin. Initially, results were unchanged. Then suddenly I felt quite a kick in the seat as I was accelerating through about 3.5K in 3rd gear. Looked down to see the boost gauge climbing past 1.5. Quickly backed off for fear of overboosting, pulled over, and removed the clamp. Back to maxing out the boost at 1 on the gauge.

So, whether or not tapping around the WG had any actual effect is questionable, but she'll make boost. Does this provide any new guidance on direction of my efforts? Refocus on the WG?

Black51

Sounds like it was stuck open, perhaps the hammer taps budged it closed. I would look into pulling the WG.

Tay-Tay

To clarify, you are getting some boost? How does it feel compared to your n/a? Check your CV is operating correctly, it may be letting all boost pressure to your WG. You also may be in overboost protection mode...

Taylor

carlege

case closed. Replace the wastegate

EJZero1

I was getting some boost with the CV to WG line clamped. Upon removing the clamp, I was back to square one, with the gauge barely reaching 1 bar regardless of load. Upon seeing the boost climb with the wastegate clamped, I got a little gunshy adn unclamped it right away for fear of overboost. Given that limited experimentation, I can't speak for how consistent the results are.

How does one check the CV for operability? FWIW, I plan on installing an MBC this summer.

Thanks again to all for help with tracking this down. That little taste of boost yesterday was awfully appetizing!

Tedro951

You're right where I was 7 years ago, but it looks like you backed out of the throttle before the clamp test was conclusive. I think I'd repeat it, getting more boost to confirm. Just my opinion, but it'll only take a few minutes to repeat the test. Replacing the wastegate will take hours...not to mention the wait for parts.

My CV connector was showing wire, the CV was brittle, and my patience was gone. I did the MBC, Vac lines, and Venturi delete at the same time.

Bri Bro

You can boost well past 20 lbs with the wastegate vacuum line disabled( clamped or open, same effect). Just be ready for it and back off of the throttle before it gets to 2 bar. I do it all the time when dialing in boost after changing things around. Just don't let it get away from you, always straight line away from cars, kid, people etc.

EJZero1

Bad day. Couldn't spend any quality time at all with my new German Mistress. (The car either! HA!)

Planning on spending a bit more time with the CV to WG line clamped off tomorrow to hopefully yield some more definitive results.

Clark's Garage says if the test yields boost, all of the mechanical components of the turbo circuit should be good. Would that then rule out a bad WG? Just trying to lead-turn the next direction of pursuit.

Thanks again to all.

hp18racer

Exhaust downstream of the gate doesn't heat up at idle, clamping the control line lets it make boost, these thing tell me the waste gate is fine. You should be looking at the cycling valve or reasons the computer would open the cycling valve. clarks-garage.com has a great set of steps to test it. My money would be on a bad cycling valve or a vacuum line to it failed.

Bri Bro

The waste gate isn't boosting every time with the line clamped, just some of the time. I am wondering if it cycles a few time if it wouldn't free up...could be the valve is sticking in the guide.

Take it out with the clamp and see if you can get it to boost more then one time in a row.

Tay-Tay

I think you can test the CV by attaching a length of wire to your battery and quickly touch one of the leads on the CV. If you hear a click that's the valve closing. IIRC if you hear no click the CV is bad.

Have you checked for boost leaks yet?? If you don't have a compressor or are have trouble finding the time to fabricate a cap for the system, you could check for vacuum leaks only. Use a spray can cap with a few wraps of duct tape -this makes it about the same size as the inlet on the IC, put your creation in the IC boot and tighten. Now disconnect the wire to the coil, maybe pull the fuel pump relay if you're feeling extra cautious, and turn the motor over for a few seconds, this will build vacuum. Now quickly run around to the engine and listen for hissing. Not the best way but its quick and easy, some boost leaks don't show using this trick.

Taylor

Black51

I've got my old CV lying around ready for a comparison test if you want it.

Tay-Tay

Interesting, certainly worth a try I hadn't heard of this happening.

Was the car sitting for a while before you purchased it?

Taylor

EJZero1

Ok then...

Re-clamped the CV to WG line and went out for a bit of a longer ride. Boost is repeatable and consistent (or as consistent as it gets?). A little bumpy at the onset, and not usually pulling upwards of 1.75 bars until 4-5K on the tach. Understand RPM is not the sole factor in boost. Confident I could have taken her to 2 bars, but again, a little hesitant with that line clamped.

Haven't had time today to pressure test the circuit, but did pick up some parts and fab this up.

Should fit in the passenger side IC coupler nicely. It's been my experience that quick connects are notoriously "hissy" when joined with their male counterparts, so I wanted the capability of pressurizing the circuit and then disconnecting the air supply. Of course, this set up leaves me with female quick connects on the car and the air hose. Hence, the double male joiner.

Will pressurize tomorrow and listen for leaks. I'm sure I'll have some, but severity aside, am I looking at possible CV issues now?

Thanks much, and more to follow tomorrow!