kiddx9

Hello. I have been trying to find the knock sensor that is suppose to be on the passenger side of the block, but just can't find the darn thing. My 87 turbo started running rich and the ecu gave 12 code. In my efforts I can't find the sensor or the connector or the wire leading to the sensor. Need help please. Thanks in advance.

86tcoupe

under the main intake on he cyl block wall ... big job.. kinda

that code maybe a symptom of the knock , not the problem .
it gets a bit tricky on cars before live data (OBD1 &2)

kiddx9

Thanks for the reply. Yeah I figured it'd be kind of a big job since I can't even get eyes on the darn thing. The ecu code gives me the knock sensor and o2 sensor together. From reading the FSM like a mad man, t looks like those two are on the same harness, so I am praying its just the connection that has erosion or unplugged. Once it cools down a bit (hot here in SoCal) I'll attempt to trace the o2 sensor wire.

My 86t runs great, I just bought the 87t where it's been sitting since 2007. gas tank has been cleaned, fuel pump serviced, from not starting at all up to this point has been progress. Hopefully I'm right about the connectors not connected or erosion that can be cleaned *fingers crossed*

rogerz

those codes are usually pretty useless in my experience. Maybe when new and guys had parts to throw at it in the dealership they had some validity but with 30 year old cars which have been hacked by a lot of people???

NismoPick

I'm confused... all my documentation says that code 12 is for the MAF... why are you looking for the knock / detonation sensor and not focusing on the MAF?

kiddx9

Sorry I just caught my typo. The ECU gave codes: 12,33,34,42 and 43. I already replaced the MAF so that's ok now. I plan on replacing the throttle sensor and fuel temp sensor as well, those are all easy and right on top of the motor. Just need to find and trace the O2 sensor wire to see why its giving me 33 and 34

NismoPick

Instead of throwing new parts at it, why not perform the tests on those sensors as shown in the FSM? Unless you like spending $$$ for no reason.

It really sounds like a ground or wiring problem with that many codes.

kiddx9

I had those extra from my 86T, trust me I try to do everything least expensive, which means yes do the tests I was just lucky to still have those good parts

I decided to take her to the shop so I can at least have a better platform. I found the O2 sensor and cleaned up the connector, I got her started and idling okish but when I attempted to take her around the block the automatic transmission wouldn't shift out of 1st, and the motor would bog if I gave her more gas than a little. I don't have the room to do a tranny flush, that's when I decided it's best to have the Japanese specialty shop diagnose everything for me.