6ocyclehum

Wondering if anyone on here has ever bought a rebuilt KLR or had theirs rebuilt. If so, I'm trying to find out what part was used to replace the pressure sensor that the air line from the intake connects to in the KLR. The original is a Motorola part, and I haven't been able to find it. The rebuilders are using something to replace this, has anyone opened up a rebuilt KLR and seen this part?
Pressure sensors are currently made for HVAC systems and other things.

Mitch

lee101315

I remember reading a thread a while back about opening up a KLR and installing a MAP sensor that read higher than 1 bar... If you can find that guy he would be able to help you

6ocyclehum

Thanks for the lead, but I've searched back a year with everything KLR related in the post and not found it. Do you remember anything else I could search for to find this?

Bri Bro

There is also a hybrid IC on the pressure transducer board. I would guess it is a custom bridge circuit. The daughter board is soldered onto the main board. I has only a couple of leads so replacing it shouldn't be hard.

I also remember the post about updating the preasure sensor, had picture and lots of details. I think it was on the 944T board

Found it...https://rennlist.com/forums/showthre...t=sensor+board

6ocyclehum

Wow, thanks! I removed the pressure sensor board, and it looked OK. Resoldered it in, no change. Have no idea how to test individual parts on it, so I'm going to try the pressure sensor first.
I sent an email to the guy that wrote the thread about updating the sensor, to see if he knew where to find a stock one. Thanks again!

Cory9584

What does the map sensor on the klr do other than operate the useless factory boost gauge?

anders44

the stock map sensor in klr is 250kpah iirc

6ocyclehum

Fault Code 3-3 from the Porsche Turbo Service Manual:
"Pressure sensor in K/CP control unit defective" - "Replace control unit".
I believe the original KLR Motorola pressure sensor reads 0-100 kpa, which would be 0-14.5 lbs of pressure.
If this sensor is defective, and cannot sense the pressure, it will send the KLR into "limp/safety" mode, reducing boost to 1.2 bar and retards timing.
I have never found any info on the original Motorola part number, but they made MPX2100 series that reads 0-100Kpa, that I think might work.
Anyone know any electronics places that might have these? I've searched all over the web but only can find data sheets. This is sort of an "obsolete" part, but people are rebuilding these somehow.....

Bri Bro

The problem with the KMPX2100 is the output voltage, you would have to add a scaling op amp to boost the output voltage to were the KLR wants it. If I can find my old KLR board, I could test the daughter board for pressure vs output voltage. I shouldn't be too hard to get something that works.

6ocyclehum

Most are showing 40mv. Which of these would work best, or at all?
http://datasheet.digchip.com/311/311...66-MPX2100.pdf

Bri Bro

There lies the problem, the voltage output of the current daughter board is in volts, not milli volts. The sensors listed would have to have a op amp added to adjust the gain. I am sure that is what the hybrid IC is doing on the original design.

6ocyclehum

Found one that puts out 5 volts:
http://www.freescale.com/files/senso...et/MPX5100.pdf
but it has 5 pins and I'm not sure how available it is.