ECU problems please help - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

Tm240sx · 03-02-2017, 10:38 PM

Hello I have some technical questions about my 1991 hatch. Nothing was done prior to what i did (stock). I was digging around under the dash and noticed an alarm system. It did not work at all so i figured i would remove it, no factory wires were cut the alarm was tapped into factory wires. After removing it the car would not start. I ran the codes and there was literally nothing and after farther tests i realized the original ECM/ECU was fried. I bought a refurbished matching serial number computer from Orielly's and they said it was a plug and play so I plugged it in and reset the codes (read 55 because new ecu) so I started the car and it ran like trash. My stock Ka24de would not idle and ran really rough, I turned the car off and re-ran the codes and it gave a 34 (knock sensor) so After replacing the knock it still shot a code 34 and after farther research I found out that a bad o2 sensor can sometimes cause a code 34 to which i found a cut o2 wire and a bad sensor so i replaced it and rewired it. Started the car again and it still runs the same.
So my question is.......
1. would removing an alarm cause any of this or could it be a deeper problem?
2. Where in the stock ka24de wiring harness does the knock sensor connect?
3. Do i need to get a factory tune on the refurbished ecu or is it good?

03-02-2017, 10:38 PM	#1
Tm240sx Join Date: Mar 2017 Location: New Mexico Posts: 4 Trader Rating: (0) Feedback Score: 0 reviews	ECU problems please help Hello I have some technical questions about my 1991 hatch. Nothing was done prior to what i did (stock). I was digging around under the dash and noticed an alarm system. It did not work at all so i figured i would remove it, no factory wires were cut the alarm was tapped into factory wires. After removing it the car would not start. I ran the codes and there was literally nothing and after farther tests i realized the original ECM/ECU was fried. I bought a refurbished matching serial number computer from Orielly's and they said it was a plug and play so I plugged it in and reset the codes (read 55 because new ecu) so I started the car and it ran like trash. My stock Ka24de would not idle and ran really rough, I turned the car off and re-ran the codes and it gave a 34 (knock sensor) so After replacing the knock it still shot a code 34 and after farther research I found out that a bad o2 sensor can sometimes cause a code 34 to which i found a cut o2 wire and a bad sensor so i replaced it and rewired it. Started the car again and it still runs the same. So my question is....... 1. would removing an alarm cause any of this or could it be a deeper problem? 2. Where in the stock ka24de wiring harness does the knock sensor connect? 3. Do i need to get a factory tune on the refurbished ecu or is it good?