boostedforlife

iTrader: (3)

Hi guys, I am have some similar problems to cccharlore but with one major thing, the tuner checked/ logged all of the perimeters and he said the MAF looked fine so I wanted to see if anyone else may have had this specif issue.


Back Ground
My car was tuned and built no problems, everything ran good, but once I went boost( greddy 18g) on my 05 g35, I started to have some bogging/ hesitating issues.




The tuner was able to get the car to run great on the dyno, but on my road test run I noticed slight hesitation on throttle around 4-5k while building boost.
But thought nothing of it. When I got back to the shop and left the dyno car went in to limp mode and got CEL for throttle relay, The tuner disabled it and I was able to drive back to the bay area(tuner was in socal) and back to bay again, drove over 1500 miles and car ran, but still had the hesitation problem but was able to drive with no limp mode)



I drove the car from the dyno to a car show no problems.( after the first time)

The next night after I left the show it started to hesitate while hitting boost.
When ever I shut off the car it ran good for a few minutes then started to hesitate again.

I would let the car sit for a min or two to cool, I did like 2-3 pulls no issues then back in to this hesitation problem.( it had seemed once I turned the car off for 30 seconds to a minute, it would run good for 1-2 minutes after, then go back in to this issue)

I checked the plugs and re gapped them per tuners instructions and car ran the same.
He originally thought the plugs were fouling at the start of boost (2500-2700) and also at peak TQ (4k-4500) Where the hesistation is most noticable

but looks like that wasn't the issue.


I drove it back to home and as soon as I got to his shop I got the random cylinder misfire code.( not sure if it has anything to do with anything)

He checked the tune. and re logged everything, He said all of the values were consistent except for the throttle. From what I remember the voltage thing was going from 4.13 to 4.09 on WOT

As I drive the less throttle the better. So say 40% part throttle while hitting boost it doesn't hesitate.
60% hesitates a little
80% hesitates more
100% hesitates for a second or 2,

Each time once I hit full boost it over comes it and drives normal after the hesitation.


One thing to note it gets worst on more boost.

on stock 5lbs from spring its not as bad,
6.5 is worst.
and 7.5lbs it hesitates the most.


so the more throttle and more boost the more issues.

ALSO Going on a high load( up grape vine or bridges and mostly 4-6th gear) around 2500-2700 around maybe 65=75% throttle the car would jerk hard, was stuck at those rpms it wouldn't go any higher and I would hear back firing/ poping sound. Only way to get the car to keep on moving I have to get to like 10% throttle or change gears.


may be same symptom but since there isnt really any boost it doesnt over come it



I thought it was the throttle body( even though mine is only one year old) so I tested it with someone elses and the car had the same problem.
I did how ever get a new CEL, which was for throttle position sensor when I swapped to another known working throttle body.


My tunner says it may be the ECU, but it was working fine before the turbo tune.



I am in no way questioning the turns abilities, I just know that if I do have to buy a ecu i want to buy new, so I want to try to exhaust any other possibilities before doing so.


I called a few other shops and no one else has any clue, so I figured to turn to the forums



Thanks anything will help.


Car set up
Uprev Osiris
Ngr Type S BOV
HPX Maf( I Did just purchase a UPREV Gt maf, but didnt realize car needs retune, so once I get this problem fixed and go e85 I will switch to that MAF)
forged internals
s7 cams
port polished head
600cc dw injectors
walbro 255 pump
greddy 18g
3inch down pipes and exhaust
mrev2
spacer
1 step colder iridium plugs ngk
466 whp on dynapack 7.5 lbs.





Thanks!

ace32x

iTrader: (10)

what are you tuned with? osiris?
and also has the missfire code only come up the once?

SE5spd

iTrader: (17)

hes on an OSIRIS and it only happened once.

str8dum1

iTrader: (11)

its a tuning issue. you need to see a better tuner before changing anything else

herrschaft

I have recently had that problem too at 4400rpm. Except I noticed this in 4th gear on a dyno, it ran fine in 3rd though.

ace32x

iTrader: (10)

this ^

boostedforlife

iTrader: (3)

My is know as one of the best on the west coast. They have a great reputation.

He was nice enough to spend a few hrs on the street
To check it out.

Other than that there is only Gtm.......

boostedforlife

iTrader: (3)

We're you able to fix it?

Does that mean if it is the Tunning could use some
More timing?

herrschaft

Not yet. I plan on having it retuned within the next two months.

Bo's350Z

What type of blow off valve do you have? If it's adjustable try adjusting the spring rate maybe it might help out alittle.

boostedforlife

iTrader: (3)

I have a Ngr Type S.

My bov is before the maf, it should show a fluxcation in the voltage if it was affecting it right? It showed constant

djamps

iTrader: (1)

Would be nice to see some logs of this problem. Otherwise we are all just pissing in the dark.

boostedforlife

iTrader: (3)

Heres a links to the logs,

The tuner gave me a richer part throttle map to also test,and I loged that as well,

I tryed to let off the gas after the boggin to idol so it was easier to stand out.


http://www.mediafire.com/?x7zbcg2mbnim7af

djamps

iTrader: (1)

Thanks for the logs, it's definately a tune issue. On tip-in you're spiking extremely lean then afterwards it's dumping fuel like no tomorrow along with silly low timing (3 - 10 deg at WOT). I also see some serious knock retard because of the lean spike and subsequent overfuelling.. mine did the same thing until it was tuned correctly. My honest opinion is get your car out of there and if possible tuning time refunded (take the license to another tuner who has extensive VQ+turbo+uprev experience, for your area GTM comes to mind). You should also swap your MAF out with a HPX or GT MAF before retuning. And don't think you can just tell your current tuner to increase timing with that rough of a fuel map, the ECU will be fighting it (bogging) worse than it is now.

boostedforlife

iTrader: (3)

Thanks for the advice,

I came across a new problem, car died on me the other day, I believe I traced it down to a bad relay, will know on wednesday. Car just wouldnt start at all. Died on my ona freeway off ramp then had to be towed back home.

I got cods for the vtc, all of the sensors were good, but the power coming from the harness was not in spec.

I currently have a hpx, but cant wait to put the uprev gt in, will do that forsure.
not sure if it makes a difference my car is 11:1. yea I know ill probably get flamed, but my engine died and I never planned on boosting it. So at the time the choice of Daily on a 8.8 or 11:1 I took the latter

so the car maxed at the 7.5 lbs of boost before it couldnt take any more due to comp. my next step after this is fixed is either a new short block or e85( dont want to push more than 550 whp or 600 on this dyno)

how would one go about telling the tunner that their tune is wrong?

Eno

iTrader: (1)

If I didn't know what I was talking about (which is a situation I'm confronted with often when it comes to FI) I might start with the logs you provided and match them up with what djamps posted and start from there. I might also be inclined to send the logs over to gtm and see if they concur. That would give you some reinforcements to call the existing tuner out and maybe get some of your money back.

With that being said last time I tried to get a shop to own up for their mistakes it didn't work out to well for me no matter how many ways I proved the point.

boostedforlife

iTrader: (3)

For now I spoke with uprev direct and they do believe it is the ecu, they said the tunner I went to in probably their best tuner hands down. I asked uprev to review the logs again for a 3rd time and they said they still recommend to try the ecu.

I will do more investigation and see what goes on.


I do understand it is hard to fight with a tunner, if they say its right they usually wont change their mind.

str8dum1

iTrader: (11)

if the tune is not right, then how can they say it is.
its not hard to fight with a tuner at all when you have the logs showing they did a horrible job

Eno

iTrader: (1)

At the same time if I go to overclock a computer and the motherboard is faulty I could be made to look like a fool too. The log shows what the car is doing- not what it is told to do, right?

So if uprev is stepping up for the tuner- maybe it is the ecu just throwing the inputs?

boostedforlife

iTrader: (3)

Im bumping this up as the car turn a turn for the worst, It was down for the last 4 months.

To sum it up, Car dies on freeway, wouldnt start. worked on the car and found some strong weird battery drain( im talking went from 12v to 8v with in 30 seconds) car was having weird signals. throwing a bunch of random codes, but when the voltages were tested on the parts it showing to still be in working order.

Kept messing with it and checking everything no luck.

had it shipped back to socal and by chance the shop found out that the Ground pin on the harness of the ecu wasnt seated all the way along with the near by throttle body pins.

So once that was fixed the car now runs again, and would solve the throttle body codes..


Car has about 500 miles on it, and I just came back to socal to drive it my self. This bogging/ jerking on WOT boost is slightly better( but I havent drivent it for over 5 months so not sure if my memory is good)

but still does it.

I called GTM, they said they wont tune my car since a greddy tt isnt something they work on. and my other tuner here says its not the tune.


what else can I do? There are only 2 known people in california that can tune uprev, if everyone still believes its the tune.


Or if not I do have the tuner verson, are there any tips for me to make some changes my self to see if it helps?

after being down for over 4 months, its nice that the car drives again but still sucks donky ***** that it isnt driving right. I was hoping to hit the track next month but that may not happen.

any new tips is really appreciated. Thank you