M Danger

Im trying to prepare my self to figure this out when i tear into it.

So the car has good vacuum, the turbo seems ok, the WG (tial) works fine, so much for checking the obvious.

What next?

I figure it either has to be one of those things that so simple you'd never bother to check, or the last/worse thing it could possibly be.

Rogue_Ant

What are you getting for boost?


Rogue

M Danger

max of about 10

Rogue_Ant

10 at redline...? What spring do you have in? Still using the CV? Does the boost peak then drop? What turbo?


Rogue

M Danger

it has and EBC, yes new CV, K29-8, Not sure i havent driven it yet, but i need to change the HG before i can test it out

SD Porsche Fan

Check your cat. Mine was plugged. Also check all vac lines. Here is a pretty good illustration. http://www.lindseyracing.com/Merchan...ry_Code=VACDIA

M Danger

No cat; 3" turbo back, all new vac lines (vac shows fine)

rberry951

I just thought of something, have you checked the function of the TPS? If the switch that tell it to go to WOT is not working, then it's just going to try to calculate load/rpm and adjust fuel/timing accordingly. With the car off just open the throttle body all the way and see if you hear/feel a click. And even if there is a click you might want to check the switch with an ohm meter to make sure it's actually working. And of course that the plug isn't full of dirt.

Regards,
Russell

M Danger

yeah im going to check that, I have 2 other TPS's i can swap out.

Nico

Does somebody know how to measure the WOT switch? And from wich contacts on the switch(1,2,3,4,5,6)?

rberry951

The switch has three contacts visible when you remove the plug. The middle one is ground, the one on the left if WOT switch and the one on the right is the idle switch. And I might even have that backward, but it doesn't matter. If you move the throttle off idle, you should hear it click and measure inifity between it and ground, with the throttle body in idle position this should read zero ohms. The WOT switch the same, not engaged infinity, engaged zero. A simple continuity tester will work well enough to tell you if one of the switches is bad. The trouble is when they get old the mechanical function of the switches tends to go when the engine gets hot, so a simple test like this on a cold engine may give results that are just fine, and then act up later. When I suspected my TPS, I replaced it without even testing it, they are pretty cheap.

Regards,
Russell

samluke

I have been fighting a similar problem for more than a year without success. My car peaks then falls back to 9/10psi. I can force the peak upwards by using restrictors etc, but it still falls back to 10psi. I run tock class so I can't change the boost control in anyway to bandaid the problem. I have tried everything, I have no cat, the wastegate is new and pressure tests perfectly, all exhast piping is open. I have changed and substituted all the control elements many times, ie DME, KLR, cycling valve, TPS, maf, knock sensor, temp sensors. I am out of ideas, its as though the car thinks there's knock but I can't understand why. The car runs fantastic its just off on power. Very, very frustrating. I have searched all the threads many times, and seen that others have had similar problems, but there never seems to be anyone fessing up to what they found, and what fixed the problem.

Nico

OK...
I seem to have this switch confused with the throttle position sensor (potentiometer), wich has 6 connectors.

Now where do I find this WOT switch? I can't find any comment about it in the Factory Workshop Manual???

rberry951

The 6 pin connector is on the AFM, right next to air box. The TPS is right on the throttle body.

For better reference to both check out clarks garage:

http://www.clarks-garage.com great stuff here...

Russell

F18Rep

This guy is mostly full of crap but some of his pics are good...B ;]