stock12

First of all, I'm not pointing any fingers. CJ Motorsports (phunk) has provided excellent support and I have no reason to believe that fault for this issue lies with the part, and if it did, I get the impression that they wouldn't hesitate to make it right. Similarly, the mechanic is a well-reviewed, regional Nissan specialist which isn't a stranger to enthusiast-oriented 370Z mods. This mechanic has provided excellent support so far and has been extremely accommodating by working late, replacing suspect parts at no extra cost, etc. I might have installed it myself, but I had a slew of mods (RRP, CMAK, oil cooler, oil pressure gauge) that I wanted installed sooner than later. Despite the excellent service from both parties, something is clearly not right and I haven't seen this issue described anywhere else on the Internet.

The fuel pump upgrade was installed with some complications. Unfortunately, I don't have as many details as I'd like but here's what I know:
- Some additional hardware and plumbing bits were required to install the RRP
- A fuse was blown at some point during installation
- After completing installation, the engine ran well but the MIL ("Service Engine Soon") was illuminated with P0181 Fuel Temperature Circuit "A" Range/Performance and P0183 Fuel Level Sensor "A" Circuit High
- I ran out of gas on a bit less than 1/4 tank, so I can confirm that the fuel gauge wasn't quite accurate

I was a bit disappointed as the reason I went with the RRP over the more affordable Z1 Motorsports Fuel Anti-Starvation kit was to keep an accurate fuel level gauge, and reliability for both track and street driving. I understood that no MIL should result from either kit, however, and CJ Motorsports confirmed this. However, it was late at night by the time I could pick up the car, which is out-of-town for me, and so I drove home to research. CJM provided some valuable insights and the mechanic agreed to look at it at no extra cost.

During the second visit to the mechanic, the resistance of the fuel temperature gauge was found to be out of spec and replaced. Again, I wasn't present for the work, but here's what I know:
- One of the connections on the circuit was moved over to an adjacent, unused terminal on the connector
- No MIL on the drive home. "Permanent" DCTs were cleared and all emissions monitors were READY, indicating that the car had completed enough cycles to test the systems and found no faults

Unfortunately, the dreaded P0181 returned a week later. I usually don't drive my car during the week, so it seemed that it ran correctly for a day or so of driving, and then stopped running correctly the next time I drove. As far as I can tell, based on the fuel level gauge, the known fuel capacity of the 370Z, and how much gas I put in the tank to fill it, the fuel level gauge has been accurate. P0183 hasn't returned.

I'm confident that the problem is isolated to the fuel temperature sensor because I don't have any fuel delivery problems, and the fuel level gauge is accurate. It seems odd to me that after the second visit, the code cleared itself on the way home (a good mix of city and highway driving with a couple of stops for gas, restroom, etc.) but returned so quickly. I wonder if a wire came loose from the connector. Or, perhaps the sensor was partially damaged somehow when connected to the problematic (?) terminal on the connector, and it took some time to manifest into a malfunction.

In any event, I have a third appointment and we are waiting for another fuel temperature sensor to be delivered from Nissan. Perhaps this one will solve the problem once and for all (third time's the charm!) but I'm prepared to have a look myself if there are any further problems. After all, nobody cares about your car as much as you do, and the weather is getting nice enough to comfortably work in the driveway.

I don't have a specific goal for posting this. I'm already receiving extra support from both phunk and the mechanic and I'm waiting for my third appointment. I guess I'm just adding this to the great databank we have here, in case some other poor soul has a similar issue in the future. I'll keep you guys posted on the resolution process, and if anyone perchance has experienced this issue or similar and has something valuable to add, I'm all ears!