AF's out of whack again
 

I'm perplexed at a problem I'm having with my tune. I recently installed a W/M setup and installed a 2.87 pulley on my SC. I took it and had it re-tuned (I have a UTEC) and the tuner set me up to have AF around 11 to 11.5 at boost. The car ran great I hit 411 hp and 338 Tq, AF's looked good and the car ran strong and was hick up free.

Now a week or two later at around 5k RPM's my AF's are going off the chart rich, it Max's my AF gauge at 10. Of course the car bogs down and falls on its face.

This has happened to me before and it was due to a faulty map sensor that was causing the UTEC to flood the motor with fuel due to it receiving a signal at times registering as much as 38 pounds of boost at 1800 RPM's. So the difference is then it would go rich at various RPM's now its limited to the upper rpm range.

So I'm guessing it's again related to the UTEC, but I'm wondering if it could also have something to do with the factory ECU trying to compensate for ? and cause issues.

I've been thinking about two things

1. Getting the ecu re flashed and keeping the UTEC.

2. Ditch the UTEC and get a new EMS, in which I'm leaning to wards a HKS Fcon V Pro, beings I have a HKS pro dealer very close to home who can install and tune it for me.

I want the car to be right, a re flash which probably won't do much is $600 or a V pro installed and tune is 3K. Big difference, I know a lot of guys are having good luck with the UTEC and if I could get my car to run right and stay right with the UTEC I'd be OK with that. But I also don't want to spend 3K for a V pro and find out it's something else. I know this is kind of a long post but I'd appreciate some advice from everyone. Thanks.

PS Heres a link to my most recent upgrade and tune, there may be something of value in there for anyone intrested in more details to help me. https://my350z.com/forum/forced-induction/368011-finally-surpassed-400-hp.html Thanks again.

If you're only shooting for low to mid 400's you can just use the stock ECU. No need for a piggyback. New MAF sensor and Osiris, you can bring the car here since we're the closest shop to you (still working on getting more mid-west and east coast Pro Tuners). You'll regain stock like driveability and civility and with Cipher you can check your stock sensors at any time.

Obviously we can't do a "flash" for FI cars, but we can tune the car here and you can always send us logs if you need anything adjusted when you get back home. Even with a drive down here, tuning time, software, MAF and anything else you might want/need done we'd be less expensive than the HKS and you'd retain all the stock sensors and controls for reliability.

Just an option. :icon44:

^^^ Curious what aftermarket MAF you're using to replace the factory MAF unit with?

We're having the stock ones modified. It's the same thing as what the Mustang guys have been doing forever and a day. The stock Nissan is practically identical to the Mustang as a matter of fact, which is why we learned about it and worked with them to make the Nissan ones.

We'll have them listed on our new site once we finish the redesign.


Also if you're serious about using the Fcon, I'd talk to the guys at http://www.tuningconcepts.com, Justin is brilliant.

Sounds pretty good, I'll do some reading up on your product. The reason I was looking at the HKS is because I have a dealer 30 min. from home. I've done the long haul for tuning before and it sucks. I also get stuck in the mind set of more is better and I know that isn't alway true. So thanks for you input and I'll check it out.

More is always better :icon8:

Only if it stays more, not: more, more more, BOOM!

Very cool. I may need one soon~ :-)

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