Boost/Acceleration Problems

[1986 944 Turbo]

Thanks Nize, like I said, the PO just had the frame laying there. Nynor, did you have the same boost/acceleration problems that I described when your knock sensor was bad?

[1986 944 Turbo]

Another question, do I have a knock sensor on my 86 turbo?

[nize]

all 951 cars have a knock sensor, even an 86 turbo.

[1986 944 Turbo]

I'm confused. Is it the little half dome shaped sensor like in the 944S or is it the KLR box? Long question short, with an error code of 2-2 what should I be checking? Thanks

[nize]

the knock sensor is sort of half-dome shaped and attached to the top of the motor block near one of the intakes.



the K/CP referenced in the manual is the knock & charge pressure unit, which is the KLR.

if all of the wires and connections check out fine, you'll probably have to replace the knock sensor itself, for $57.25;
http://www.pelicanparts.com/cgi-bin/ksearch/PEL_search.cgi?command=show_part_page&please_wait= N&make=POR&model=944M&section=FULinj&page=3&bookma rk=13&part_number=944-606-145-00-M14

i just noticed the manual says there's two of them. hmm, i wonder where the other one is.

[1986 944 Turbo]

Thanks Nize, your advice is much appreciated.

[Rogue_Ant]

There is only one knock sensor...


-Rogue

[1986 944 Turbo]

Nize: I have heard that this knock sensor is not needed. Porsche only used them to test the engine at the factory? Does this mean that the KLR is most likely causing my problem? Thanks again.

[nize]

Originally Posted by 1986 944 Turbo

Nize: I have heard that this knock sensor is not needed. Porsche only used them to test the engine at the factory? Does this mean that the KLR is most likely causing my problem? Thanks again.

who told you that? i can tell you that the knock sensor is most definitely needed if you want any reliability from the motor.

[1986 944 Turbo]

I was not getting any reading from the knock sensor when I checked the #11 and 13 terminals on the KLR plug. I removed the knock counter and put the ohm meter on the 2 pins coming out of the knock sensor. I did not get any reading. Does the knock sensor need to be on the block in order to get a reading? If not, then it looks like I need a knock sensor. Thanks

[nize]

i'm not sure if the knock sensor will give a reading when it's not detecting anything. i do remember seeing a knock sensor diagnosis how-to somewhere, but i can't seem to find it now. you might do a bit of searching around and see if you can find info on how to diagnose/test the knock sensor itself.

[Rogue_Ant]

Sounds like you have a bad knock sensor. You should be able to get an ohm reading.


-Rogue

[1986 944 Turbo]

Thanks Rogue. I will order one.

[1986 944 Turbo]

Rogue, I pulled the knock sensor off and put the ohm meter on the 2 pins on the sensor. Should I still have got a resistence reading? Just checking before I order one. Thanks

[Rogue_Ant]

Yes, you should have gotten a resistance. Most knock sensors are 500-1000ohms, IIRC. If you're getting an open circuit, the knock sensor is bad.


-Rogue

[1986 944 Turbo]

Thanks Rogue, everyones help on this forum is much appreciated.

[nynor]

did you pull the intake manifold? just curious....

[1986 944 Turbo]

Nynor, I did not. I was able to get to the sensor between the ports. Thats why I was asking about the ohm reading on the sensor itself. To make sure it was the sensor and not the wires. Like I said, I put an ohm meter on the 2 pins on the sensor, I did not get a reading so I am assuming it is the sensor and not the wires. I am also having the KLR checked as a precaution. Before this problem, I never even heard of a knock sensor. Thanks

[nynor]

i was able to do that, but it took me hours and i scraped the crap out of my hands. strong work.

[1986 944 Turbo]

Well I replaced the knock sensor and the KLR. I only drove the car about 4 miles last night but it seems to be working good. Hopefully I'll get to drive it more this weekend. Thanks for everyones help.