pikey7

My Datalogger is telling me The TPS is at 0.6v with no input from my right foot. Does this sound about right to you guys? The switch just clicks when I touch the throttle when under the bonnet, yet I have a bit of a varying idle. The multimeter is coming out in the morning to see if the unit is faulty, but I might as well start simple!

Cheers

Lorenfb

"The switch just clicks when I touch the throttle when under the bonnet, yet I have a bit of a varying idle."

Are you checking the idle switch or the REAL TPS (many on this forum mix them up)?
The idle switch is an input to the DME (pin 2) and is either closed ( 0 ohms) or open
above idle. The REAL TPS provides an input to the KLR and has an output of 0-5 volts.
It has three pins, 5 volt input, ground, & a variable output as a function of the throttle
position. The KLR pins are, 21, 22, & 23.

hmd

Mike,

This is my data logger graph of TPS at idle (I got TPS from pin 21 of the KLR).

Lorenfb

Just use a voltmeter and see that the voltage varies from your .40 volts to over
4.0 volts. Don't waste time with a data logger now while troubleshooting.

hosrom_951

Mike: Some electronics such as the MAFterburner only show ~0.70v on WOT from the TPS.

Luis de Prat

The TPS in my S2 clicked like that also, but replacing it solved a random hesitation problem I had been having for months! YMMV

Lorenfb

"This is my data logger graph of TPS at idle (I got TPS from pin 21 of the KLR)."

Pin 21 of the KLR is the voltage & it should be 5.0 volts.
Pin 22 is the one that varies, per my Porsche manuals.

"The TPS in my S2 clicked like that also, but replacing it solved a random hesitation problem I had been having for months!" YMMV

TPS elements don't clic. They're a potentiometer which is variable resistive device.
If it clicks, you got a problem.

hosrom_951

Loren: I believe he ment the adjustment of the TPS to the throttle position, basically, you hear a faint click when the throttle body is open, and another click when it closes. Not the actually TPS clicking internally

pikey7

HI Guys,

Thanks for the input.

The clicking I was reffering to is indeed the TPS itself. By operating the throttle under the bonnet, The switch is normally off, and with a slight touch on the throttle cam, it does indeed click. I remember when I replaced the unit about a year ago, that was the reccommendation from all the technical websites.

The voltage I'm referring to is logged by the Mafterburner, and comes in from Pin 22 on the KLR. Off hand, I can't remember what the values are on WOT, I'll have to check my logs, but IIRC we are talking around 4v.

All I'm worried about really is that even thought the switch is supposedly closing, a 0.6v at idle suggests the TPS itself is actually not functioning correctly. I was hoping that there may have been some maladjustment on my part, and therefore an easy fix, rather than having to spend, again, on another unit.

Cheers

special tool

"TPS elements don't clic. They're a potentiometer which is variable resistive device.
If it clicks, you got a problem."


Are you kidding?? Your website says you design DME systems and you don't know how a Porsche TPS functions??? That's a good one.

IF YOUR TPS DOESN'T CLICK WHEN YOU OPEN IT, IT MOST LIKELY IS SLIGHTLY OUT OF ADJUSTMENT WITH THE IDLE STOP SCREW ON YOUR THROTTLE BODY. You may bring it back into sync by loosening the 2 small phillips head screws on the side of the TPS and turning until this noise is heard at opening and closing of the throttle.

Lorenfb

"Are you kidding?? Your website says you design DME systems and you don't know how a Porsche TPS functions??? That's a good one." - special tool -

Again totally confused! You need help as others do. There's the throttle switches
and a TPS sensor. Get it right, please and don't confuse the forum as you're been
doing incorectly it appears for a long time.

Let's get in step with the real world about automotive electronics and call the system
elements by their proper designations.

As I said, TPSs DON"T click unless you're been mis-informed by some.

Luis de Prat

Hi Loren,

We appreciate your expertise. Specifically, when "we" say Throttle Position Switch or TPS, we are referring to the part pictured below. What do you call it?

When properly installed, a TPS (as pictured) will "click" by pulling on the throttle cable with the engine off.

I have found, however, that this "click" alone is not sufficient indication of it working properly. Replacing this part with a new one that also "clicked" solved a hesitation problem in my 944S2 which I had been chasing for months.

Again, thanks for your input.

special tool

#120 400 clicks when it opens and closes, wiseass.

I can take apart a 944 and put it hback together again in 1 day. You are a speculator who preys on the pride of people who ACTUALLY KNOW WHAT THE HELL THEY ARE DOING to leech out information so you can steal it.
I told you, I have your number.

Luis de Prat

Hi Jim, what's going on? 900 posts is hardly troll status.

I just don't understand the argument against the clicking -it's a widely known indication of a correctly adjusted TPS, like you say.

special tool

He/she is not responding because he has to go consult his books about Bosch part numbers because he has NO familiarity with them. This is the same reason that I just happen to know, off the top of my head, the part number for our TPS.