NA -> TII Swap Knock Sensor Wire Question
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Old Car Preservationist
Joined: Mar 2004
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From: tempe Az
NA -> TII Swap Knock Sensor Wire Question
I have been doing a TII swap, and I have a question about the knock sensor wire. The car is a 90 convertible and the motor is a j-spec S5 turbo. I am using an S5 NA harness. From the many sources I have read, I am supposed to use pin 2M for the knock sensor. On the NA harness, this pin supposedly has a black wire with a white stripe (b/w) attached to it. The NA harness I'm using has a yellow wire with a black stripe attached to pin 2M. The connector on the end of that wire is white and connects to a solenoid valve with a white sticker on it. I have detailed the process on a web site that I'm building. Here is a link to the incomplete site.
Mikes Convertible TII Project
This white solenoid valve connector does have a b/w wire connected to it, but it only seems to be a common ground for the knock sensor, the afm and... one other sensor... I don't recall which right off.
So what's the deal? Am I using the correct wire? Is my harness different from other people's harnesses?
Thanks,
Mikes Convertible TII Project
This white solenoid valve connector does have a b/w wire connected to it, but it only seems to be a common ground for the knock sensor, the afm and... one other sensor... I don't recall which right off.
So what's the deal? Am I using the correct wire? Is my harness different from other people's harnesses?
Thanks,
HAILERS
Joined: May 2001
Posts: 20,563
Likes: 27
From: FORT WORTH, TEXAS,USA
Most of the solenoids have one wire that is black/white. The black/whtie is 12vdc power for the solenoids. The other wire in each solenoid is sent a ground signal from the ECU to open/shut the solenoid at a given time.
Never put a black/white wire to ground on a RX7.
On a na car the 2m wire is a yellow/black wire that goes from the ECU to the VDI solenoids plug on the engine. You could extract that wire and connect it to the knock sensors wire. This is not the most desirable way though.
The knock sensor is supposed to be a shielded wire. The center conductor connects to the knock sensor on one end and the ECU's 2M on the other end. The shielded wire around that center conductor is supposed to be grounded at one end or the other of that cable. It matters not which end. You do that because the knock sensor itself puts out a very small voltage in milivolts that can be influenced by other wiring. The grounded shield prevents that interference.
In other words to ape what Mazda did on the turbo car, you would have to buy a shielded wire and piggy back it on the EM harness from the knock sensor itself to the pin 2M on the ECU plug.
My personal predjudice says it's not worth it. You have to make that decision yourself. DONE.
Never put a black/white wire to ground on a RX7.
On a na car the 2m wire is a yellow/black wire that goes from the ECU to the VDI solenoids plug on the engine. You could extract that wire and connect it to the knock sensors wire. This is not the most desirable way though.
The knock sensor is supposed to be a shielded wire. The center conductor connects to the knock sensor on one end and the ECU's 2M on the other end. The shielded wire around that center conductor is supposed to be grounded at one end or the other of that cable. It matters not which end. You do that because the knock sensor itself puts out a very small voltage in milivolts that can be influenced by other wiring. The grounded shield prevents that interference.
In other words to ape what Mazda did on the turbo car, you would have to buy a shielded wire and piggy back it on the EM harness from the knock sensor itself to the pin 2M on the ECU plug.
My personal predjudice says it's not worth it. You have to make that decision yourself. DONE.
Last edited by HAILERS; Aug 14, 2007 at 02:04 PM.
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