s14 ka24de knock sensor woes

[fuco8210]

I have searched extensively on this...
I picked up a 95 zenki that had the motor replaced with one from a kouki and was throwing codes 32 and 34.. It looks like he used the zenki obd1 intake manifold even though the throttle body has the extra plug for autos which isnt hooked up. (not sure if they all have the extra plug?)
The real problem seems to be the knock sensor.. He cut the shielded wire and this is what it looked like when i got it. http://i20.photobucket.com/albums/b243/fuco8210/IMG_20100615_113346.jpg
I replaced the knock sensor, wired everything up and taped it all the best i could. I hooked up a multimeter to the wires and was getting 5v unplugged and 2.48 at idle which is good from what I understand.

The car is not even driveable with the ks hooked up. It runs ok down the street and then starts pulling so much timing it will crawl and barely move. Can anyone shed some insight because i have to drive with it unhooked and it still doesnt run great or get as good of mileage as it should. Thanks everyone.

[Homer_Simpson]

I would replace the shielded wire.

I had a similar problem before and it was due to me splicing right in the middle of the shielded section. I fixed it by replacing the wire with a continuous shield wire form the sensor all the way to the ECU.

That's some shitty wiring right there. I would go through the whole harness to see what else the previous owner half-assed on.

[fuco8210]

So does the wire split and ground by the ecu? or does the wires stay shielded into the ecu pin?

[Homer_Simpson]

So does the wire split and ground by the ecu? or does the wires stay shielded into the ecu pin?

IIRC it is split from the shielded wire and then spliced into a bunch of other grounds right before the connector. I can't recall what is is like on the S14 ECU since I did the wiring for an S13 blacktop.

[fuco8210]

Update.. I took a trip to the junk yard and there wasn't any s14's there so i cut the harness from an s13 and pulled out the wire along with the knock sensor sub-harness.

When I got home I ran the wires ,cut the ks (white) wire a few inches from the ecu pin and spliced the new wire onto it... This is where i become baffled; with the ignition on i am getting 5 volts from the ks wire BUT as soon as i splice the new wire from the s13 onto it the voltage drops to 0!! I can even splice it back onto the original wire and get 5 volts in the engine bay but as soon as i hook up the s13 wire it immediately drops to 0.. Can anyone shed some light on why this is happening?

[fuco8210]

So i figured out the new wire loses power once it is grounded by the ecu. It gives me the right readings of 4.8v ign on and 2.48v at idle but as soon as i ground it i get 0v. I finally found a zenki worth keeping and its going to drive me to an early grave. Any ideas?

[pakman1013]

This is pretty hilarious cuz i have the same problem. I had my mechanic change the sensor a few weeks back but the problem arose just a week later. i have no idea what to do.. :[

[fuco8210]

I still haven't figured it out.. I'm thinking it might be something else too because its running lean and starting to get worse.. and i have the knock sensor unplugged

[fuco8210]

Fuel pressure is 37psi at idle 42ish psi at wot so its got good fuel pressure. Still running lean though, backfiring through the intake and my 02 and plugs are white. I am going to check timing tomorrow. It should not be leaning out just because of the knock sensor.

[jbmintz]

if it was falsely sensing knock, it would put it onto the knock map right? Causing it to run ridiculously rich