JohnK944T

I have been playing around with the diagnostic port on my '86 951. I have been getting a 3-3 code that indicates a defective pressure sensor in the K/CP Control Unit.

What is the K/CP??

What would be the performance issue with a bad pressure sensor in this unit?

-jk

special tool

knock / charging pressure aka klr. Find that air problem yet?
Bye the way, does your factory boost guage register "1" with key in on position and engine stopped?
4-1 in conjunction with 3-3 can be a tps wiring problem, check that harness and make sure it is well connected.

JohnK944T

K/CP = KLR, perfect, I am guessing expensive too. The Boost gage does read 1 bar with key on and engine off. I have not found an air leak yet and when I do you'll be the first to hear..

I am a little suspicious of the potentiometer in the TPS. I have a new one coming, but also plan to check and see if the resistance changes linearly during the full cycle of the throttle.

I read that you can spray carb cleaner on the hoses. If idle changes you found your leak. Didn't sound like the best method..

I have checked the easy hoses all looks good.

-jk

special tool

Don't limit your seach to a boost leak. Consider also vacuum problems and exhaust problems - these are insidious faults and can really benefit from having a partner to help you look. Also double check your 12 volt maf supply as superjet said.