hotlanta_87

My 350z recently won't rev higher than 5200rpm. I've tried adjusting the computer rev limiter built into the stock car and it's not making a difference. I've set that limiter high and I've set it low in a reasonable band. Prior to the last time I took my car into the shop it was getting to the redline limit just fine. I don't know if the shop messed with it or if there's something I can do to troubleshoot it. Any ideas?

stuartc323

might want to get it check at a dealership.

pro_350z

iTrader: (3)

That computer rev limiter that you messed with just adjusts when the little red rev light comes on. It doesn't actually raise or lower your rev limit.

DavesZ#3

iTrader: (26)

^^^ this. You haven't reached the rev limiter until the gas is cut and the power drops for a instant then goes back up again and bounce off again.

icer5160

iTrader: (4)

1) Have you taken it to a shop?

2) Did you have an uprev tune or any kind of ECU tune done?

3) If the ECU was tuned/flashed, there could be multiple profiles setup. You might have gotten stuck on a low rev limit profile. I know it's possible to do this with the uprev tune and some owners actually prefer having a low rev limit profile to prevent valets from going nuts in their car! It's also nice to have if a buddy or family member gets ahold of your keys while you're out of town/incapacitated!

hotlanta_87

I took it to a shop that is very familiar with Zs. I did not ask them to touch anything to do with the computer. They fixed a couple exhaust problems last time it was in, so I would hope they didnt need to check anything. I think my best option is to go back to that shop and ask some direct questions. I could put the pedal to the floor and it would not rev higher than the 5200rpm, it would just bounce and ping right at that amount. Probably can't do anything myself. Ugh..

stlslv350z

iTrader: (1)

when you talk about rev. are u talking about the car as of in N or in gear?
If its in N. I don't think you can rev any higher.

hotlanta_87

my car was in gear. i think i've got it figured out now. my car is turboed and used to have a lot of exhaust leaks. it was tuned with those leaks. now that the leaks are gone, the turbo is more efficient and now forcing more air into the engine than designed for with the current tune. so i need to reprogram all of that and/or get into the fuel system. i dont know what this problem is called, but at least it makes sense.

hotlanta_87

i just heard of an 'uprev' tune. how could i figure out what i have, if any at all? if have one, how can you change profiles?

icer5160

iTrader: (4)

Hey Hotlanta,

All the details can be found at their website:
http://uprev.com/

I believe you use a combination of the cruise control buttons on the steering wheel to switch between profiles. Then a light in your gauge cluster will blink a number of times to indicate the profile number you've selected. Last year I had an uprev Osiris tune done on my 2006 Z by Rob over at Z Car Garage. The car runs fantastic with the tune he did, but unfortunately since I have a base model, I don't have cruise control and therefore cannot switch between profiles even though my ECU can store up to 5.

But the best way to find out if uprev was used to tune your ECU, would be to ask the tuners who installed the twin turbo. If you had exhaust leaks and you shored them up, then a re-tune is a must have with a TT. If you can't figure out what was done and by whom, then I would just have your ECU completely re-flashed and tuned.

Good luck getting this problem sorted out!

icer5160

iTrader: (4)

Here's a link to the Uprev Osiris documentation:

http://uprev.com/UpdateFiles/softwar...er%20Guide.pdf

Step 4 shows how switching between profiles or "maps" is done.