fejjj

Did you check to make sure your Cat is not clogged like I mentioned?

Austin09

Would I have to take the WG pipe off to check? I will have to do that at the weekend since I drive the car every day.

use2windsurf

I was reading about the difference between the turbos on Clarks garage (GETTING MY FIRST 951 THIS WEEKEND!!) and I when I read the part below, I remembered this post and thought I would pass it along

From Clarks Garage
The cycling valve is controlled by the KLR Unit (Knock Regulator Unit). The KLR receives signals both directly and from the DME Control Unit to determine how the cycling valve should be controlled. The chips in the KLR have a boost limit which comes preset from the factory. When the actual boost reaches the computers preset limit, the KLR sends a signal to the cycling valve to close which allows exhaust pressure to open the wastegate. If the cycling valve fails, loses power, or a problem occurs in the KLR unit, the cycling valve will fail fully closed. In this mode boost is limited to approximately 1.2 bar. This is essentially the boost at which the force of the exhaust pressure will overcome the wastegate diaphragm spring pressure.

Austin09

Thanks for posting that. I went through the diagnostic for the CV last week (I think) but clamping off the hose to the WG and seeing if it boosts past 1.2. It didn't.

I find that test a little confusing as the WG is surely sprung shut, and shut means exhaust gasses don't go to the turbo?

I think my WG is stuck open as the x over pipe gets hot straight away, or its electrical.

Since the car was standing and had some work done on it with the bonnet and badge panel removed, this kind of makes sense.
Any idea what else I should test? Blink test has thrown no fault codes.

CBR944

After going through something a little similar with my 952, look first at the obvious things - are the big intercooler hoses (from turbo to intercooler to intake) all secure? Especially check the one at the turbo - it's a little hard to get to with everything in place, but you should be able to test if it's on tightly by tugging it away from the turbo where it joins the hard pipe. If there aren't any obvious big leaks then check the turbo itself. Might wasn't making strange noises either but the vanes were toast - some sort of crud must have entered the intake somewhere. You have to take the air filter and air flow meter assembly and the j-boot to get to it. Worth checking before you start pulling the wastegate.

NM'87 951

If you read the pasted information in the other post, you see that the exhaust gas pushes the spring open naturally at 1.2 bar, which is where you are stuck. I'm not sure how having the hood (bonnet) off would do anything to your WG, aside from perhaps pull the hose off one end or another. If you wanna pull the WG and rebuild, or get a stocker from someone for cheap or borrowed, you may be able to swap and check? You could do the same for KLR and/or the DME if you want. Borrowing a known working from someone will let you eliminate those other things from the Clarks garage checklist.

Keep us up to date and take pictures... helps and makes this more interesting

NM'87 951

Check the cycling valve connections. If they are corroded or broken off, the car will only register 0.2bar (1.2bar absolute) and will give no error codes

from clarks 944 Turbo FAQ page. Reading it will put you down the right path as it covers more than just checking your wastegate.

Then I went to youtube and found out how to check my catalytic converter.

Good luck!

Austin09

Hi again. Still not solved but I've been running down a few of the diagnostics. What does this seem to indicate:

1/ no faults on block test after drive. Led lights up on ignition but nothing when I start the car or after a drive

2/ vacuum test (as per video on first page) shows either pipe or gw doesn't hold vacuum. What does this mean?

3/ clamping and or disconnecting WG to cycling valve pipe and driving has same issue. See test drive video.

4/ the exhaust pipe to the turbo gets warms up, but now at as quickly as the exhaust, so perhaps the WG is closed?

5/ car boosted perfectly to 1.75 pre body shop now it's not working.

I've bought a spare WG and the exhaust section connecting to it in case, from the states. Things here in the UK are silly money.

Austin09

It looks like I can't change the CV without taking the inlet manifold off, which looks like a bit of a nightmare.
Perhaps I just start changing the least costly parts since my diagnostics are points to electrical issue, but no fault code. Perhaps the CV solenoid is bad?

jeffrsmith

"Easter Egging" even the least expensive parts is one of the most expensive methods of troubleshooting.

NM'87 951

The intake manifold is really not that hard to take off. A few bolts that hold on brackets for the oil dipstick and the cruise control cable and the fuel rail are really it. Taking off the intake and intercooler piping is just undoing clamps and wiggling stuff out. The project can seem daunting, and if you use the car daily then perhaps wait till you have a weekend off.

I know someone said you can check your CV by disconnecting the electrical connection and testing the CV. I don't remember the exact procedure or what readings you would need to see, but I think a functioning CV will 'click' when the two leads are charged. There are threads and such for a better method of how to check the electrics on your CV and you wouldn't have to take the manifold off for that.

If you do get to taking the manifold off, it is rather easy. Just be really really careful about your bolts (use anti sieze on the threads) and make sure you have extra washers and a intake manifold gasket handy for when you reassemble.

Keep up the hunt!! Took me the better part of 3 months to find and fix enough 'little' things to solve my boost and vacuum issues. Things are much better now, so trust there is a solution... you may just need to ride the bus a few days while you take her apart a bit.

Austin09

Can anyone help me with my vacuum testing?
I'm trying to determine if there is a vacuum leak anywhere in the system - the lines look fine, but some of the connectors may be loose.
If I connect my pump to the elbow connectors on the bow off valve, or from under the throttle body, or from the Y connector on the fuel regulator, I'm getting immediate leak of the vacuum. Should these lines hold vacuum for some time?
There is also a hose going to one of the intercooler pipes, should this hold any vacuum?

I've also just noticed the hose onto the WG is a bit loose, the hose can move a little, so I'll nip that up tomorrow when I jack it up.

Austin09

I've been trying to fault test and eliminate parts of the system I can get to and test. In addition to the above, i've gone through every single vacuum line today and all hold pressure fine.
The jubilee on top the WG could do with nipping up but I can't reach that without a ramp.

So where I'm at - PLEASE feel free to correct if i'm misunderstanding the system here.

1/ I think I can rule out the CV and WG pipe. I disconnected this pipe and did a test drive. Still the same. The CV should increase pressure on top of the WG to limit boost. Disconnecting stops this happening.

2/ In case I'm in a computer controlled limited mode, I did a blink test with a DIY led. Ignition on, light is on, start the car, no codes. After test drive no codes. Pull knock sensor or maf, you get a code. So can rule out sensor issues (unless KLR is knackered)

3/ WG isn't stuck open, as the xover pipe isn't getting that hot under idle.

4/ Took of the blow off valve today. All fine, just dirty. Cleaned it and reinstalled.

Where do I go next? I don't have a ramp so haven't been able to take off WG and inspect exhaust system or WG. I did check for leaking exhaust gases, there is some leak, but the same as before it went to the body shop.

According to all the forums and websites my problem is now limited to
1/ Sticking WG
2/ Mechanical turbo issue
3/ KLR issue
4/ Exhaust gases leaking
5/ Oil level in cooling system

I really need this fixed ASAP. I'll have to rent a ramp and try fitting a s/h waste gate unless anyone has any other ideas.

Austin09

So that this thread is useful for other owners in the future - please see attached a useful fault diagnosis test.

I believe I'm at the stage now or take the WG off and inspect, or take off the inlet manifold.

CBR944

Pulling the air filter assembly, the AFM and the J boot is a lot easier than changing over the wastegate. I'd do that first for at least a visual check of the turbo before you do the wastegate. After all, there's not much that the bodyshop could have done to affect wastegate operation, but if they had the intercooler off, there's a chance that crud could have got into the intake system (or intercooler pipe, then through BOV to the intake), destroying your turbo...