hey guys,

got a 91 n/a, I have replaced plugs, EFI harness, timing belt and 3 injectors just recently. The car is not misfiring, idles perefectly smooth, however when i rev the car and lean into it, it just feels course and vibrates pretty bad. Accelaration and pickup seem fine, but not stellar. Not sure what could be causing this, any ideas???? I was wondering if it could be one of the other injectors.

Also, I have just recently re-routed the knock sensor. The code was cleared, now I wondering, could this vibration all still be cause I didnt locate the knock sensor in the original spot. HAS ANYONE HAD A KNOCK SENSOR FAIL, AND CAN DESCRIBE TO ME WHAT IT SOUNDED LIKE BEFORE AND AFTER YOU RELOCATED IT? I've had it into the nissan dealership 4 times for this and they say its running fine, but 4 months ago the car revved smooth and silky without the slightest hint of vibration or harshness.

Comments welcome!!!

 

possibly a coil pack?

 

I will be watching this thread closely. I have a z31 turbo but mine runs almost EXACTLY the same way. Mine used to run silky smooth, but one day it started running like that. Checked ecu codes, came up with 34 and 42. I changed the knock sensor, cleared codes, and it still runs the same. I want mine to run butter smooth again.

 

I had a same thing on my car it runs kinda bad and rough but it picks up fine
I went to go get my car checked out and everything was fine. Connections good sparks good and coils good but it turns out that my Power Transistor Unit (PTU) was part of the factory recall back in the early 90s model. The previous owner never got it done I'm the second owner. And I took my Z to the local Nissan dealer and that ran my VIN number and it shows that it the recall was never done soo they went ahead and gave my an appointment and had it replaced with a newer style PTU and now my car runs like a champ

 

OHM injectors and test PTU. If you have already replaced 3, chances are the others are going out as well.