Cass007

iTrader: (34)

It wasn't the idle that was the issue, it was coming off a WOT run and then taking my foot off the gas completely that was causing a stumble, so the idle was bumped to prevent any stalling issue. I thought the hot start issue was universal with Utec and larger injectors .

Either way, that POS is out of my car now for good.

Blck350z

iTrader: (10)

Just have them wait till the "real" tuner gets back. I worked on my car for 1.5 months and Cass007... like he said ... he has been carless for almost a year!!! consider yourself lucky that they didn't blow the motor tinkering around and that it has only been 2 weeks. Just have them LEAVE the car sit there till the tuner gets back.

Also my Utec did have hotstart issues with RC550 injectors That goes w/out saying (get used to it if you're not changing anytime soon) and the idling issue... it should idle fine... i had my idle set to 750 rpm and my friend has his set to 1000....

lope483

there wasnt an AP, it was a diagnostic device...cant remember what he called it though

lope483

the problem is there isnt a "real VQ tuning shop" within 300 miles of me. and the only one id want to look at my car is Forged.

and i talked to Ryan at forged this afternoon. he said they have done a ton of installs with the APS kit and pump+injectors w/ UTEC and they almost never run into this issue. when they do its usually a vacuum leak or the intake air control valve.

it cant be a vacuum leak though cause they did a smoke leak test.

lope483

thats what ryan @ forged said but they did a smoke test.

lope483

they are used to tuning Termi mustangs so they arent super familiar with the UTEC. and they have only done one 350zTT install in the past so this is their first G35.

they are recommending a fuel return setup now. i said EVERYONE on the forums, as well as ryan when i talked ot him, said ou dont need one unless you are running serious hp, like 500+. they said they talked to Jermaine at turboXS and thats what HE told them to do.

lope483

they confirmed this morning that it was specifically a hot start issue. it fored right up and idled perfectly this morning when the engine was cold.

regardless, i have to wait for the shop owner/tuner to come back. he said he didnt want them ****ing with it anymore and he would finish tuning it when he got back. on freaking monday.

Chef-J

iTrader: (58)

https://my350z.com/forum/tuning/4504...re-please.html

So what, where you want us to post?

Chef-J

iTrader: (58)

At 400whp, you don't need RFS, but you are at "it's good to have". But you can walk away with it. RFS, atleast stage 0 will cost you pretty close to 600~700 dollars ( labor/part ) It's up to you.

str8dum1

iTrader: (11)

you def dont need a RFS to solve the problem that you are having....

hot start does not affect the idle though. Once started it should run perfectly.
Just wait til monday and see how that goes.

Do you have a boost/vac gauge? You should be seeing -10psi or -20mmHg at idle. Anything higher means you have a leak.

lope483

yea thats pretty much my plan. and yes i have a boost guage and its dead on. they did a smoke test too and nothing.

G3po

iTrader: (8)

Bumping the idle may be needed "if you ever upgrade to lumpy cams" and it masks some idling issues . But it does not help " off thottle" starting. Sometimes when you must tap the throttle to get the UTEC to get it's chit together in the first few seconds , you may also thow annoying mis-fire codes. With a minor reflash (ie via Osirus" you should not need to do this and idle and startup operation operation will be just like stock even with the DW 600ccs.

UTEC is not a paper-weight "per-se" but it has several annying behaviors.
The Haltech or UTec + Osirus provide far more seemless stock-like behavior.

TBH I was able to get a better idle with a unihip and 600s vs a UTEC. The main reason I ditched the UTEC is that it was extremely "notchy" at high RPM , when you drop in and out of boost. The CPU is not adequate to keep up with the rapid MAF ot MAP transitions. So it's kinda useless for road course use. Ask any reputable shop that has UTEC in Z/G experience for a similar scoop.

lope483

do i really need a UTEC PLUS Osiris? cant i just go with Osiris and ditch the UTEC?

str8dum1

iTrader: (11)

he means a simple reflash to correct for the bigger injectors. The UTEC can only scale MAF voltage so much and the stock ECU wants to fight that. Reflashing the ECU with Osirus to correct for the new injectors will make the UTEC transition perfectly between on and off boost. Most people just live with the UTEC. I think its just fine.

Of course, you can get a full dyno tune using Osirus and drop the UTEC completely.

lope483

what would you recommend? it just kills me to have to buy an Osiris tune when ive already spent the money for UTEC. i know i can always sell it, but its just a hassle.

from the comments on the boards however, it seems Osiris is just a much better platform anyway.

G3po

iTrader: (8)

Yes what I meant was a refolash. Osirus is just the "new" way to do it .It's easier to go back to stock and no need for shipping your ECU. Also note an Osirus reflash can get you a few things UTEC never can can: raised rev limiter, raised speed limiter, no hot or cold start issues etc.

Whether to ditch UTEC or not?. It depends on how you want to use the car , how **** you may be and ifyou have the funds. If UTEC and the PMAS had been available to me 2.5 years ago , I wouid have tried that route.

For me personally I was very disappointed with the UTECH and it's un-advertised features. PS . My tuner (ZCG) also hated the user interface. Note ZCG in SJ has done doezens of succesful APS installs. I note you live in Sactown. Be stealth, and avoid gettgin popped by the the po-po , I learned that the hard way.

lope483

so i got my car back yeasterday.

we ditched the UTEC and went with an Osiris reflash. the idle problem all but went away. it is a little lumpy still but no stalling and its a million times better. its getting better still with every mile i put on the car.

we dyno'd at 7.4psi and hit 397rwhp and 377rwtq. after we iron all the bugs out we're gonna bump it to 9psi for a high boost setting for "special occations"

i am absolutely thrilled with the car. im at work right now so i dont have pics or the dyno sheet but will get them when i can. this thing hauls ***.

the only thing i really dont like is the Z1 clutch. its a 6-puck and a single-mass flywheel and chatters like CRAZY. its also a ***** to start in 1st. but other than that its ok. ill be upgrading to a better streetable twin-disk setup in the future.

ill definitely be updating this thread later though. thanks again for all the support and advice.

G3po

iTrader: (8)

So are you now running the re-flash with the stock MAF or the PMAS?

Also if you bump the idle up 200rpm or so , the idle will be less bumpy and you clutch will be less annoying in stop-n-go. To get an idea of that imporvement jsut comare how it drives with the AC ov vs. off. AC on the ECU bumps the idle.