Dal Heger

I'm sorry, I still say read the blink codes. I can't see it being the cycling valve. He only has 112k km on the car the cycling valve should be just fine. The cycling valve is working, it does boost properly sometimes leading me to believe that there is something else wrong - it is going into limp mode. If it was a failing cycling valve it wouldn't matter if he rebooted the system, it would come on and off randomly as he was driving the car. The cycling valve is too simple to just stop working, then start again with a restart.

That being said, I'd love to find a cycling valve that works the same way, but is made of metal. I hate those freaking plastic nipples that always threaten to break off.

I stand by my diagnosis, it's not the cycling valve. Maybe I'm wrong.

Dal.

black944 turbo

That is why I say the KLR.

Rock

Wont the car run in limp mode on knock? So maybe the car is knocking sometimes and causing it to run in limp mode. Could this be a shatty knock sensor or am I way off.

Dal Heger

Rock, you're right on. It won't go into safe mode until it reads a certain number of knock events in a certain time.

Who knows? I don't have the car in front of me. It's tough to diagnose on the internet.

Dal.

Rock

Dal you were the one that told me that the cars go into limp mode on knock.

Luis de Prat

I have a stock Porsche 993 BOV on the car which was replaced about 2 years ago.

How do I test the KLR?

tommye

Luis, check here for blink code instructions:

http://members.rennlist.com/951_race...linkCodes.html

Your problem can have many sources.....
- I would not rule out the CV, although other things are probably more likely.
- I suggest you check, clean and use contact spray on the ThrottlePositionSensor and AirFlowMonitor connectors - this is quite easy. There are of course many other electrical connectors to check as well....

Cheers,
Tommy

IPSC

My car (89 951 with 113100 on the clock ) did this same thing while it still had the restrictor valve in the Banjo bolt. When I went to an MBC and bypassed the cycling valve it stopped so maybe the cycling valve suggestion is right on?

IPSC

Rock

Argh I LOVE turbo cabriolets. Theyre so beautiful. Luis, your car could have no motor, and you could ride flintstones style everywhere, it would still be beautiful.

Dal Heger

Well yes, of course that will work, BUT you have just removed the only "check engine light" this car has. The only way that you'll know something is wrong with the car (lean condition - knock, failed fuel injector, etc.) is that the KLR will (using the CV) limit the boost to 1.2 bar absolute, limp home mode. I had a friend who put a hole through his piston because of a failed injector on 1 cylinder. He was getting great boost (manual boost controller) with no other issues right up to the point that the car became a mosquito fogger.

I personally would not bypass the cycling valve. If you think that you can hear knock at high rpms (where it is most likely to happen and cause damage) then good for you. I'm not willing to take that chance.

Fix the problem, don't put a band-aid to mask it.

Just my opinion. I'd rather fix the cause of the problems, whatever they are.

Dal.

IPSC

The Manual boost control bypassing the cycling valve is not a band aid fix.I am running a TIAL 38mm in single port mode it is necesary to do it that way or at least that is what the Tial people explained to me.

IPSC

black944 turbo

I agree with you Dal if your car is stock. If it is chipped then it is much better to run an MBC.

IPSC

I gotta start puttin my mods in the sig line or something, mine is far from stock. It has a MAF with chips and a K27 among other goddies that I am constantly messing with. But, my strange overboost go into limp mode thing went away when I went to the MBC.

IPSC

Dal Heger

Right, the "strange overboost go into limp mode" will go away with a manual controller because you're taking the CV which controls boost and tells you you're in limp mode out of the system. Did this start happening when you went to the K27? Did you get chips for the K27? I'm just interested.

The Tial (single port) shouldn't have made a difference because all the CV does is provide pressure to the system (just like a manual boost controller) under the control of the KLR. The KLR uses closed loop feedback to control the pressure via the CV, it should have adjusted the pressure as it needed. Was the line to the wastegate in good shape or even connected to the cv? Those little plastic nipples love to break off over time and many heat cycles.

Oh well, to each their own. I'm currently not willing to remove that safety feature. I'd love to be able to set up a check engine light for these cars though!

Dal.

Luis de Prat

OK, I'm going to give reading the blink codes a whirl before pulling the intake manifold. Any suggestions for making a LED tester?