Tom M'Guinn

The KLR has a WOT 'switch' that is triggered when the TPS opens enough. When the switch is triggered, it tells the DME to run off its WOT maps. I think the m-tune logger displays the status of that switch, but it's very easy to test either way. The signal is one of the pins in the diagnostic port under the hood, so very easy to get to and monitor on a multimeter. If yours is not triggering, it good be the KLR (bad solder joints maybe), the TPS or the harness... Worth testing anyway.

JacRyann

Along with Tom's info, here's some additional tidbits to clear things up:

- there is NO WOT switch in the TPS. If you test its output and it goes up to about 4v at WOT, it's fine.

- stock 951 FPR is 2.5-bar (944S uses 3.5-bar FPR). Fuel-pressure should be about 37-38psi at idle with vacuum disconnected. Around 30psi connected

- to determine status of WOT signal from KLR to DME, connect an LED. Give it +12v on one side through a 200k resistor and connect anode to KLR WOT line (grounds when active)

Test and measure parts and confirm they are indeed bad before replacing. Or else you'll have a giant pile of spares you won't need for a decade, if ever.

Cyberpunky

Thanks guys. Clarks say to mearsure resistance across pins 22 and 23 of KLR to test TPS. I knew there was a switch and was thinking it was wot but was the idle I was thinking of. I think the KLR may not be telling dme to use wot maps. If I make up an LED as per Jac's suggestion, what wire am I am checking on ?

Will google DME inputs and see if I can find it. Might end up mounting the LED to the ones for my Vitesse knock LEDs, as would look cool to see when you hit WOT everytime

Cyberpunky

OK found pin 3 on DME is WOT input from KLR and pin 18 on KLR is output.

SamGrant951

I was having voltage drop at the pump and my car would go lean / not boost - replaced the wiring and noted I had a battery with a bad cell. I kept it on a trickle charger so even though it started / seemed fine was causing some goofy issues. It was 9 years old, didn't even realize it. Just an easy thing to check that I overlooked for a long time.

Tom M'Guinn

That's right, but no need to dig into the harness at all to test the WOT signal. Pin 18 of the KLR is wired directly to the diagnostic port in the engine bay (the round black port a few inches wide, with a cap over it).

Check the voltage between pins B and C -- i.e., pin by itself at the 6 o'clock position, and the pin in the 1 o'clock position. It should show 5 volts on light throttle and show ground (0 volts) when the WOT "switch" is active. It wouldn't be the first thing that comes to mind for a lean-boosting car, but it's on the list and one of the easier things to test.

JacRyann

Another indirect way to determining WOT map usage is to monitor the factory O2 sensor, either with LED gauge or voltmeter. When DME switches to WOT map, O2 sensor stops dithering and holds a steady voltage.

Cyberpunky

Thanks guys that info has helped a lot. Had no voltage at all at test port so we checked TPS harness and 2 wires were broken. Now have 4.9 volts at test port. Progress

Cyberpunky

Will know more in 2 days but after reading test point 9 in DME KLR test plan manual, I am left thinking that Porsche's "replace KLR" as the suggested solution, may be correct, due to the results of the tests

Tom M'Guinn

What were the results?

Cyberpunky

My understanding is that it showed 4.9volts even on Wot

azbanks

Updates?