This might be a stupid question, but does ECU case itself have to be bolted down and grounded to the chassis?


Background:
I have a 96 ecu in the stock location and everything runs fine except for check engine lights due to evap.


I bought a 95 ecu off a running car (for evap delete) and just to test it, I just plugged it up and left it on the carpet. The car started and idled perfect, but drove pretty rough(afr was jumping back and forth between 10 and 16, plus shaking in the shifter and steering wheel while accelerating). It also had a hard time revving past 4500 rpm (not like its bouncing off the limiter, more like the car just loses power). I plugged the 96 ecu back and everything was back to normal.


I'm thinking the ecu case has to be grounded, and it would make sense knowing how Nissan has stupid grounds (like between the transmission and block). i just want to confirm before I dismount my factory ecu for the 95 ecu.

PS: no bent pins on the ecu or corrosion.

 

One of the org members, Pmohr, has a how-to video for making the ECU blink the check engine codes. In that video, he states that he has his ECU on an extension cable because he doesn't run with the ECU under the dash. I think this implies that you don't need the case of the ECU grounded. However, you could always use a jumper wire to ground the case while you have the ECU hanging out.

 

Got the ECU working fine. It was my EMU patch harness...

 

does anyone else start laughing at the word "grounded" now??????