P0181 after Road Race Pump

[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!

[osbornsm]

Doesn't that feel better now?

[BettyZ]

Osbornsm bucking for a side hustle as the forum therapist.

[SouthArk370Z]

The blown fuse and bad temp readings may be related. May have sent too much current through the sensor and/or burned some insulation off of a wire.
Finding an intermittent problem can be a royal PITA. Good luck.

[Elmo370z]

I haven’t had any issues related to that with my rrp. I have over 12,000 miles on my unit. Fuel gauge misreading could be related with your mechanic not bending the baffle back far enough on the drivers side or he dropped the level sensor they are very sensitive. Blowing fuses has to be a wiring issues, why was the connections moved over? Did the mechanic ground the rrp properly and where did he wire the power supply for the rrp? Since you didn’t do the work or present when it was done it’s kind of hard to diagnose the issue.

[stock12]

Thanks for the support, osbornsm! lol. It is quite disheartening after spending thousands on parts and labour to drive home with a MIL but the support from both phunk (who replied within minutes on my late-night email) and my mechanic (who has put in hours of extra labour at no additional charge) is very reassuring.

To the rest of you, I'll keep these suggestions in mind if/when I take a look at the fuel pump myself. I expect that the fuel pump itself is grounded correctly because there are no fuel starvation issues.

[RN SHARK]

It has to be an install issue. I installed my own RRP and top hat and have very limited wiring skills. Ask Phunk, as I emailed him about simple crimping questions that he must’ve laughed at. I have had no issues with mine except for a little pump whine when it is hot out and it is working hard on track.

[Mejia_370Z]

Where did you find a fuel temp sensor? Can’t find one that says it’s for a 370z.

[Elmo370z]

Originally Posted by RN SHARK

It has to be an install issue. I installed my own RRP and top hat and have very limited wiring skills. Ask Phunk, as I emailed him about simple crimping questions that he must’ve laughed at. I have had no issues with mine except for a little pump whine when it is hot out and it is working hard on track.

Mechanic probably installed it in the fuse panel box incorrectly. Should of ran in it to the battery.

[2011 Nismo#91]

Originally Posted by Elmo370z

Mechanic probably installed it in the fuse panel box incorrectly. Should of ran in it to the battery.

This was the source of my problems with the installation of this kit. The only additional things that were needed were related to the power supply to the kit otherwise everything was included, odd that extra hardware and plumbing was needed on yours. I had to in the end run a dedicated wire all the way to the battery for this kit (tried to utilize the sub power wire but that lead to blown fuses and burnt insulation, it needs a substantial amount of current.

[Elmo370z]

Originally Posted by 2011 Nismo#91

This was the source of my problems with the installation of this kit. The only additional things that were needed were related to the power supply to the kit otherwise everything was included, odd that extra hardware and plumbing was needed on yours. I had to in the end run a dedicated wire all the way to the battery for this kit (tried to utilize the sub power wire but that lead to blown fuses and burnt insulation, it needs a substantial amount of current.

I didn’t need anything additional. The kit provided everything I needed to get it up and running. I may have worded my
Previous statement wrong. I didn’t mess with tapping into the fuse box, I just ran the wire to the battery

[stock12]

I forgot to update this before, but for posterity, the third mechanic appointment fixed the problem, which was a wire coming loose after driving around for a bit. Thus, the order of events was:

1. During initial installation, a fuse and a fuel temperature sensor were blown. RRP eventually seemed to be installed correctly. MIL resulted.

2. Temperature sensor was replaced, but a wire was not securely fastened. MIL was cleared.

3. Insecure wire came loose after some driving around. MIL returned.

4. Wire was securely attached. MIL has been clear for thousands of kms.