Gomez015

I know this is an old thread, but any update on what the problem was?

I installed this Z1 kit on my G37 2 weeks ago. I barely drove it after install until track day this past weekend. It was a CCW layout so not too many hard right turns and the starvation kit probably wasn't too necessary, but my fuel gauge would just drop to completely empty while racing, even when there was plenty of fuel in the car. This is so scary. But then the gauge would randomly start working again (not sure even the reading was even correct) and then go out again when it felt like it. Towards the end of the day when I was running around what I guessed to be a quarter tank, the tank read empty and never came back on. I can't be having no reading. The purpose of this kit was to be able to allow me to race under half a tank without fuel cutoff to save weight. But I can't optimize my fuel weight if I never know when I'm going to run out of gas. Getting towed off the track isn't cheap.

I opened up the tank the next day to check out what was going on. My Lever Arm Sensors had plenty of room to move freely, nothing blocking them. But I noticed that the passenger side (with main pump) was completely full of fuel while my drivers side was bone dry empty. I guess the kit was doing its job, but its causing too many more issues.

I called Z1 to ask what they knew about this. They said that they will often install this kit with a "relay or switch" but were unable to tell me any of the details about it. They also told me I probably shouldn't have the starvation pump running if its not pulling any fuel. But yeah, no solutions offered. So much for an "all in one kit" that needs unknown additional equipment to work properly.

Then I called Specialty Z because they just tuned my car after I installed this kit and my E85 conversion components. They said that if the lever arm on only 1 side of the tank reads a completely empty tank, even if the other is full, the computer will freak out and tell you the tank is empty. Makes sense. So far, more helpful than Z1. They also told me that when they install this kit, they don't wire it to the main fuel pump (contrary to Z1's instructions). Instead they wire the starvation pump all the way to the front of the car using a "Spal Relay kit" ($70). They said that with this kit, you can turn off the starvation pump when you're not racing so that the tank evens out and the pump isn't pulling air. I'm not much of a wiring guy, and the original wiring for the starvation kit was already a bit out of my comfort zone, so there's no way I want to mess with anything like this. Its just crazy to me that Z1's kit is dysfunctional like this with no mention of additional equipment necessary to work properly.

So I've provided the info that I found out. Do you guys know any other solutions besides wiring to the front of my car? Is the OEM metal tube that runs from 1 side of the tank to the other supposed to even out the tank when it sits overnight?