so recently i went ahead and got the APS tuner kit deal that Z1 was doing, which included the APS tuner TT kit, 660cc DW injectors, a UTEC, MAF, and APS exhaust. i also got a Z1 6-puck clutch and lightened flywheel combo and HKS EVC6 and Autometer Nexus guages. its taken about a week and a couple days so far, but this is where my tuning guys are.

they have everything installed and they were supposed to get a base tune on the dyno so i could pick it up and drive it till the shop owner (who is also the main tuner) gets back from vacation next monday and can give me a really good tune. unfortunately things werent going too well when i went to pick the car up yesterday after work.

i went in and they had it looked like they were trying to get the car to idle properly without dying. they said they had to diagnose a misfire earlier, which happened to be a bad plug. so for now they put the stock plugs in till the new ones could get in. they were sitting in it messing with the UTEC and accessport-looking diagnosing computer. im not familiar with the exact one they were using. but the idle was AWFUL. i could smell how rich the car was running. the main installer was revving the car from like 100-600ish rpms to get it to stay idling. if he didnt constantly keep revving it it would die. finally it was idling and the AFR was like 14-14.5. i asked why the hell it was doing that and they said it was because the UTEC doesnt have an easy way to go in and change injector size from the stock 380cc to 660cc and the stock ECU was tripping all over itself trying to figure it out. he said it wasnt that big a deal though they would just have to go in and pull fuel throughout the rev range. they said cause the UTEC is done through hyperterminal it would just be a pain and tedious.

the only thing that worries me is in my thread about my build in the FI forum a member said that the car should idle perfectly with very slight tweaking of the UTEC and i shouldnt be running into this issue at all and i definutely shouldnt have to pull fuel. anyone have any advice?

 

oh yeah, this is on an 04 6mt G coupe

 

all they had to do was change the 0% load column in the fueling table to around -10 and it should idle perfectly with an AFR of mid to high 14's

umm how did they tune the car at all if they didnt wanna use the hyperterminal. Thats the only way to tune the UTEC?? Are you sure they werent tryin to use a reflash instead of the UTEC? The UTEC has to be run with a laptop.

I'd be very nevous about anything they did to your car.

 

did they install a fuel return kit?

 

good to know.

and its not that they didnt WANT to use HT, its just that they said it was a PITA. and yeah, they had the laptop hooked up and HT open so they were for sure using the UTEC

 

no no fuel return. walbro 255lph fuel pump and 660cc DW injectors.

actually talked to them about an hour ago and they said they were working on a 4500rpm cutoff. said its pretty much shutting down above 4500rpm. also said the fuel curve was "fat" and they were fixing it.

 

I don't really get what's base tune on dyno They could simply download other turbo base map from turboxs.com
it is pretty much similar, put your car on dyno for base map is waste a time (IMO) you can not get on it anyway.

http://www.turboxs.com/utec350zupdate.htm

But I will never bring a car from a shop if it's not tune or ready. There is no point to bring it back home if you can not run your car like normal or no boost. It's your car tho.

Anyway, Str8dum1 knows about Utec.

 

ok so i just got back from the shop. MAJOR idling issues. it ran flawlessly on the dyno however. made 389hp 369tq @ 6.5psi. cant ****ing WAIT to get this car on the road.

but anyway, yeah so its got a MAJOR idling problem. like, it wont even turn over unless you give it a little gas, then itll just die if you dont feather the gas like right away. it dies when you come to a stop or just take your foot off the gas and let it idle. the AFR was hard to tell cause you have to keep feathering the throttle, but when it finally would settle down and idle, it was at like 400rpm and the AFR was like 14.7. my tech thinks it has to do with the drive-by-wire throttle. he thinks the car is getting enough fuel but not nearly enough air at idle because for some reason the throttle isnt opening up all the way. we tried setting the 0% load column to -10, all the way to -30 and it just got worse. any ideas?

 

wow -30 ?!?!? ur killing the maf

 

they didnt keep it that way. set it to -10. they were just trying to fix the issue

 

your probably gonna have a hard time getting that to idle on 660cc injectors with a high volume pump and no return kit, with a Utec as the only control. Most injectors are flowed at 43psi and factory 350z fuel pressure is 51 psi, so those 660's are actually like 715's at idle, and the utec can only do so much....

I would recommend an Osiris to supplement that Utec(if not just get rid of that utec), that way u can do the latency correction as well as the start fueling correction in the factory ECU to help alleviate the UTEC "hot start issues" everybody has

 

could i just go with Osiris and say **** the UTEC?

 

just an update....i talked to them this afternoon and they are recommending a fuel return setup. i talked to Ryan at Forged and he said you shouldnt need one unless youre making serious power, like 500+. thats generally when ive read all over these forums too. regardless what i do i have to wait till the tuner/owner comes back on monday cause he doesnt want them ****ing with it anymore. hes going to tune it fully when he gets back.

i was thinking about going with UpRev and Osiris and selling the UTEC but Ryan told me they do like 80% of their installs with UTEC and have like zero problems with it. either way this is a freaking headache.

 

Are they a uprev pro tuner??

 

they are in the process of getting the license. they have done like 5 tunes so far.

 

Were the swirl jet and regulator drilled when installed the walbro?

 

should they have been? i really dont know. i can ask them though.

 

See in the DIY section, there is a thread there on CJ-Motorsports to install the Walbro and if the swirl jet and regulator are not drilled excessive pressure of fuel is buildup at idle that may cause poor idle quality.
No implying that is the case but check it out.

 

we did this, and it helped a little but the lumpy idle was still there. i ended up saying eff the UTEC and going with Osiris. the stalling issue went completely away but now theres a somewhat lumpy idle. its not nearly as bad as with the UTEC though. it jusr cycles from 800-1000rpm. MUCH better though. its getting better with every mile i put on the car as well so i think we just have to let the ECU relearn and itll be fine.

thanks for all the feedback though. this was a real headache and now i can just enjoy the car.

 

just reading this thread is giving me doubts about utecs.. im scurred.