Ahhh, if it were only that easy. Just went out to have a look and, ashamedly, can't quite narrow down which line to clamp. I'm thinking it's the 5/16 ID rubber hose that connects to a small cylinder with an electrical connection under the intake (cycling valve?). This hose leads down to the top of what I believe to be the wastegate at the passenger side lower rear of the engine in the exhaust circuit.

I know, no pics, but does this sound right?

Thanks much!

 

From 944online.com:



You will find cycling valve under intake manifold..


Nice car BTW

 

Thanks! Appreciate the confirmation.

I'm off to clamp and drive! Results to follow...

 

If your vacuum lines are the original, change them all out anyways. You'll be doing it sooner or later. Plus, that will either solve your problem or eliminate vacuum, lines as the culprit.

 

Agreed. Planned on replacing them all anyway. It was the first thing I did to my 944 in pursuit of another issue.

RESULTS OF TEST: Clamped the line between the cycling valve and the waste gate and took her out for a drive. Drive was cautious, but still saw up to 4K on the tach. Boost gauge saw very little, if any change. In fact, if there was any change at all, boost gauge indicated lower boost as we never saw 1 bar.

What might this indicate as the next step in my pursuit?

Thanks again. Learning the ropes of the Turbo is proving Rennlist membership invaluable.

 

I bet your wastegate is stuck open... but I could be wrong!

Let me know if you want a used OEM one off my 87, I am upgrading.. it is still on teh pipe right now, and I will be out of town will next weekend, but can pull it once I am back!

 

It may be the wastgate, but before you start crawling around under your car, I would pressure test the system. Some boost/vac leaks are not apparent until on boost. Check this link https://rennlist.com/forums/944-turb...ke-system.html

...and welcome to 951 ownership, you'll appreciate the turbo at elevation...well, once we get it working.


Taylor

 

I'd start with fixing the leaks....you're bound to have some, but they would be massive if you aren't building ANY boost with the WG clamped. If that doesn't help, the WG would be my next item.
Unfortunately, this is the admission price to 951 ownership. At least for many of us.

Taylor is right, though. Once you feel 15lbs of boost, you won't mind doing all of the other maintenance items!

 

Is there any place that sells adapters for tial wg?

 

http://www.speedforceracing.com/index.php?ukey=home

Taylor

 

Thanks all for the inputs. I (kind of) knew what I was getting into with this car. Knew it needed enough tinkering to keep me from getting bored for a while, anyway.

Checked the Arnnworx site but didn't see the intake system pressurization fitting offered anywhere. Does anyone know if he ever produced and offered it, or was it just a suggested make-it-yourself-if-you-need-it kind of thing?

At any rate, in the process of sourcing a good used wastegate to fix my issue or rule it out as a culprit. Full vacuum line replacement still on the near-term to-do list.

Thanks again for the inputs and words of support!

 

once the weather warms up we should gofor a drive

 

Welcome to the Club of 951 impulse buyers.

 

Thanks!

 

He used to offer it, but I haven't seen it offered since he changed his site around 3 months ago. It's pretty easy if you go to Home Depot/Lowes with the rubber boot, find a PVC end cap with a 1/2" NTP threaded into it already, then you can put a quick disconnect barb in the threaded hole and wrap some electrical tape around the OD of the PVC to help with sealing. Dial your compressor down to 10psi (shop air pressure would be a bad thing), hook it up to the quick disconnect, and start listening or spraying soapy water and look for leaks. Known problem areas: J-Boot, Turbo to IC pipe coupler, IC pipe to IC coupler, IC pipe to TB coupler, TB seals, fittings in the manifold, seals between the intake manifold and head and fuel injector seals.