2G No ground on Map, CAM, and crank sensor issue

[lapointebrett]

I switched to an Evo 8 ECU for tuning purposes because that's what my tuner prefers. I got the new ECU in and made sure all sensors were reading correctly before bringing it to the tuner. I verified that I had spark and fuel going to the cylinders as well as IAT and MAP sensor readings because I switched to speed density before swapping to the new ECU.

After making sure everything was working properly I trailered my car to the tuner because he's in the next city over. After getting to the tuner my MAP sensor stopped working for unknown reasons but car still would run very poorly when spraying extra starting fluid to get it going. Had to take it back home to get new MAP sensor installed and tried to get it started again to make sure MAP sensor was working. MAP sensor wasn't reading so after using a multimeter I realized there was no continuity for ground on the MAP sensor.

Just to get it reading since it was the only issue before I hotwired a ground wire to the negative terminal on the battery and the MAP sensor started reading on the logs but still no start. I rented a noid light and went to check to make sure I had injector pulse and for some reason now there's no injector pulse as well as no spark.

After checking for ground continuity on the cam and crank sensor it turns out there's no ground either one of those sensors either. I've double checked all my grounds in the engine bay and everything seems good. I don't understand what could have happened to make me lose ground on the MAP, cam, and crank sensor especially since I know I had spark and fuel when I was with the tuner. Somehow in the time from being with the tuner and getting the car home I've lost ground on all 3 sensors.

Any ideas on what the issue could be?

This is really causing a roadblock for me as I am not the most knowledgeable when it comes to wiring and I'm so close to finally having my car finished and running properly. Any advice or tips would greatly be appreciated, I just want to get this figured out so I can drive my car again.

 

[Drewpy Dawg]

Check the wiring for continuity between the ground pin on the sensor plugs and the sensor ground pin at the ECU or whatever chassis point they ground to. The injectors don’t connect directly to ground, the ECU pulls them to ground, so it sounds like a ground problem in or near the ECU.