Sorry bro, he wasnt around. I believe hes not working in that dealer anymore :ugh2:

damn :(

I'm going to keep this updated and to the point because I don't want anyone to go through what I'm going through. It's been such a long process but here's what I can recall. Two main parties have looked at my car. One of which was nissan, and they haven't been helpful, so I don't know how much of what they say is valid. Also, my car has FI so something else I ran into was a vacuum leak which caused a significant cut in hp and I couldn't build boost. All occurrences are inconsistent and random. Only consistent thing was I could rely on my car to crap out on start up.

Assuming I had the vacuum leak:
Car shut off one day while driving and wouldn't start. Nissan said a hose on the fuel pump had come off and $600 they connected it.

Car went into limp mode. I went out of town and a week later I towed it to Nissan and it magically started up again. They cleared some codes and said nothing was wrong with it.

Fixed vacuum leak. If you're facing the hood, bottom right by the wastegate, there's a little plastic part that was crushed for me and so it was leaking air. Stillen said the $5 part isn't covered under warranty because they're known to get damaged (which makes no sense to me)

Vacuum leak fixed:
Car still doesn't know what to do when it starts. Idles are up and down. I start driving and the car spews black smoke out the pipes slowly inching around my neighborhood. A few minutes and a couple stop signs later the car starts taking off normally. At idle the car will still freak out some times even after warmed up.

Got my throttle bodies cleaned. Idle was a little wonky but then cleared up. I engaged reverse and it started acting weird a few seconds later. Waited a min, acted normal. Drove it home normal. Everything's been normal. I will continue to drive it around and see if anything else goes wrong.

Next step is getting an oil pressure gauge and a/f gauge to see if maybe it's a fuel issue.

For me, cleaned my throttle bodies at 30,000 miles, and no problem since. I'm at 41,000 miles right now. But if you're FI it could be more than just TB's. Hope you find the cause :tiphat:

Update: I've been about 95% problem free. If it chokes it's usually on a cold start. Beyond that it won't hold the choke, it'll just stutter once and get back. If the idle goes crazy it usually fixes itself after a few seconds of searching up and down and/or a couple revs

I also noticed, sitting in stop and go traffic, that if I let off more clutch than I give more gas on a take off it causes the car to enter that confused idle state. Will continue to update once oil pressure gauge goes in next week

Another update: Still no consistency. The weather cooled down and the car was behaiving quite well until today. Nothing drastic in the weather so it may have just been luck. Still no oil pressure gauge but I noticed upon start up the a/f gauge stays at 14.x when it works. A few seconds after start up, the gauge will drop to it's lowest, 10, and that's when I start having problems. After driving for a little bit it clears up. Turned the car on and off a few times and I think it only started normally once.

UPDATE: Oil pressure is normal. Our next focus is the fuel pump. I've also noticed when the car is down to 3-4 dots of gas left is when problems tend to be more predominant. Car also runs a bit rich sometimes in 6th gear

Keep the updates coming. If I can't figure out what's causing this issue in the next few months the G is going up for sale.

F Nissan right now so pissed off at this car

update: no conclusive results. It's clearly an airflow issue. potentially fuel pump, throttle body related, or even a bad map (doubtful).

On start up a/f gauge drops to 10 but car spits out black so I know it's rich. If I was as rich as my car I could have had this solved by now...

@Business Kat. It sounds like you're sucking air in from somewhere. Have you removed, cleaned, and re-sealed the TB's intake manifold, and lower manifolds?

I had an issue similar and the upper manifold actually was cracked and air was escaping/entering when it shouldn't be. This is past the sensors so they never picked up on it.

I ended up replacing that as well as my fuel pump, and have been problem free.

Update: I'm hoping it's finally solved. Bad fuel injector

My car started to sound like a busted old mustang/helicopter. A code finally popped up and we figured out that the fuel injector in cylinder 5 stopped working. Had it replaced, it's been 2 days now, and I haven't had any problems with it. I'm still getting 5psi boost vs 8 but I'm pretty sure it's from the same part that leaked before. I will definitely update again if this was the problem.

I'm going to be SO MAD AT STILLEN if this was the problem. First, they sent me the wrong map when I got the car and told me I'd have to wait 2 weeks before they could send me another one. Then, the small plastic part that was crushed and was causing my air leak "wasn't covered" by the warranty and they wanted me to pay $15 shipping for like a $5 part. AND NOW a faulty fuel injector???? I spent thousands trouble shooting and Stillen didn't help me through any of it. When people on the forum said stillen aint what they used to be I should have listened. Done venting - stay tuned for more updates

I hope with the new injector you can solve that problem man! :tup:

It's only had 2 episodes since the fuel injector was swapped and they were rather short. I think the bulk of the matter was a bad fuel injector from Stillen as well as another plastic piece that was crushed a few months back from their kit.

Momma said if you don't have anything nice to say, don't say anything at all. BUT I want you guys to know that Stillen absolutely screwed me with all this. They sent me a wrong tune day 1 so I couldn't even drive it. I had to get it towed for a new tune. Then they said the plastic piece isn't covered under warranty after I had spent hundreds trying to figure out what the problem was. Once that piece was replaced their fuel injector died which, guess what, isn't part of the warranty.

Never using stillen for anything ever again.

Damn bro sorry to know your story.... Its really a PITA when you cant not solve issues like this by the easy way :shakes head:

Update: Car went into limp mode. Was fine after a restart but check engine was still on. Stalled once. Limp mode 3 more times. Made it to a mechanic who cleared the code P1239 and the car is normal again. I have to drive ~100 miles tomorrow so we'll see what happens. HOPE I DON'T MISS MY APPOINTMENTS #overit #thxstillen #nevermodacar #saveupforamaserati #oragtr #justdontmod

Update: Code was the tps. Did some research and apparently the tps sensor stillen provides with their kits have a little bit of a reputation for going bad. Unplugged it, checked the cable, it had power flowing, plugged it back, cleared codes, didn't go back into limp mode. But now we're back at square one where on startup is has a panic attack and then acts normal. Sometimes while driving it'll go super lean as well but usually letting off the gas and letting the car reset for a second cures it.

Ya'll were right. It may be too early to call it but I think we solved it!!

Stillen makes a very high quality throttle position sensor extension that comes with their kit. The technology in this sensor is incredible. It's able to absorb heat and far beyond any cable I've ever come across.

Sarcasm aside, the sensor overheats and will start with false voltage readings and ultimately will cause the car to go into limp mode. This is why idle RPMs go wonky, random cuts in power will occur, and why the cars will go into limp mode.

Someone at Uprev had the same problems as me so they were able to fix it pretty easily. I can't believe this $40 cable and a $5 plastic elbow join cost me thousands in damages and repairs. Stillen told me the plastic peice wasn't covered under the warranty and when I contacted them about the TPS they said the warranty was only good for a year. Can't express how dissatisfied I am with Stillen.

I'll update again but I already can tell there's a massive difference driving it.

So a bodgy throttle body harness extender was the cause?

Hey guys, unfortunately posting back in this thread as i have "the same" issue with hesitation between 2.5-3.5k rpms again, except this time cleaning throttle bodies has not worked. I also cleaned the maf sensors, air filters are clean, reset ecu, checked and "reset" brake switch, checked for intake leaks, using same 93oct fuel as always, oil temp is good and in operating temps when this happens, recently changed engine oil and its topped up and drove the car a few days before this and all was good. In other word, im frickin' stomped!

Rain has been pouring here in PR the last few days but i havent taken the car out much, plus no flooding in my area.

Taking it tomorrow to the dealer to see whats going on. :confused:

Update: took the Z to the dealer and as expected, they dont know what the hell is wrong with it :shakes head:

I told them what i had done so far as inspecting, cleaning, etc.

They asked for two more days to see if they can find the problem, lets see what happens :ugh2:

So i called nissan dealer today to check on the status of my car and turns out neither the service advisor or technician are working today :shakes head:

The service advisor said that they would need until wednesdays to work on my car, but it turns out its just because they were OFF today. I ask to speak with the service manager and he says that its because they cannot assign a different technician to work on my car if one has already started, which makes sense, but when i ask the manager why didnt the advisor tell me this so i could pick up my car and not miss work today and bring it back on wednesday, all hell breaks loose and the manager gets pissed off saying what difference does it make since i already knew they would need the car until wednesday :eekdance:

I then again explain that i missed work when i could have picked up my car and go to work today, and obviously tell him i dont like his tone of voice :gtfo2:

From there its all downhill and i get piiiiiiiissed. All in all, cant wait to pick up my car and file a complaint on his :icon23:

Not sure if im being a bit of a d!ck with expecting the advisor to be more clear about why they needed more time, but the service manager should have not behaved the way he did and talk to a customer like that. I was upset but in no way disrespecting him until he started yapping away like he did when i questioned him. Already got the nissan customer affairs phone number cause im calling and reporting him :mad:

Thanks for listening, guys ;)

Update: dealer called and told me that the problem are the throtle bodies and they need to be replaced. $2,200 for both TBs, plus labor and taxes :eekdance:

Fortunately, i have extended warranty but now i have to wait for the approval saying they will cover it. Im pretty frustrated right now and a bit dissapointed that a 3 year old car needs to have TB's replaced. I know this sort of stuff happens, but this is a yearly problem. Ill wait for the warranty response, but right now i feel i dont want to keep the Z after this. :shakes head:

IMO - This is a known problem in the Z34 and it is documented and has been reported several times over. You shouldn't need to pay a dime for them to be replaced since it was some sort of manufacturing defect.

FYI - I have had zero issues since having my replaced about a year and half ago and I've put about 25k miles on it since then (I think). Which, if I recall correctly, is more miles than when I first started noticing issues when she was brand new.

Any how, good luck getting things figured out. I personally know how much of a PITA this whole ordeal can be and I really hope your extended warranty will cover the parts if Nissan won't cover it as a known defect.

My Z is supercharged, I don't know what yours is but I finally got mine to work properly. They had to replace a throttle body on mine but the cause of it was the throttle position sensor that plugged into it. I had gotten all kinds of codes and problems and FINALLY it threw out tps after everything else had died.

We replaced the crappy tps extension stillen provided and insulated a new one as well as replacing the throttle body. The guys at uprev said that it was just the part that the tps connects to but you can't just replace that so they had to do the whole thing. Don't know if I got shafted on that but my car finally works! I want to make a sticky about this because this problem was a nightmare and I don't want anyone else to go through it.

Hope the throttle bodies fix your problem.

yup... a $40 cable from Stillen. They also sent me a bodgy plastic elbow joint, a $5 part that they told me wasn't covered by warranty, and the map for the wrong vehicle when I got the kit. Thousands of dollars I'll never see again. Gj stillen

Lack of Power - Limp Mode - Shut Offs - SOLVED

Read through the whole thread for details but here's the gist of it.

Car: 2013 370z with stillen supercharger. Installed and tuned in CA. Moved to Texas. Problems started.

Problems: Car hesitated under 3k rpm and then would take off just fine. Random limp modes. Random codes involving throttle body, air flow, etc. Car would sputter at idle. Couldn't find correct idle at idle. Misfires. Stalls. You name it.

Solution: After taking it to a mechanic time and time again to fix whatever problems would happen we finally found the source. Throttle bodies if you catch it too late, otherwise it's the throttle position sensor. When you get Stillens kit they send you an extension cable. This cable is conveniently placed in an area exposed to heat. Here is said sensor:
http://i66.tinypic.com/2h5qgpe.jpg

In my case, so they told me, the sensor would over heat and cause all these problems. Sometimes it would totally shut the car down as a safety mechanism. Also, in my case, we had to replace the throttle body because the little thing the tps plugs into, that's attached to the throttle body, needed to be replaced as it was more or less fried. But they don't make that individual part so we had to replace the whole thing.

Here is the new insulated cable:
http://i63.tinypic.com/rr5sba.jpg
As you can see it's much heftier than than before.

Here is the little connector thingy that got fried. Or maybe they upsold me:
http://i67.tinypic.com/2aje63q.jpg

And here is another angle of where the cable plugs into the thingy on the throttle body:
http://i68.tinypic.com/2na5vo7.jpg

And here is a shot of the whole thing because why not:
http://i65.tinypic.com/2rykhef.jpg

For my duration with this problem all problems were random and inconclusive. A restart fixed it half the time. One time I waited 2 days and it turn on. Finally had it towed to nissan where the car started right up perfectly fine. Someone with a non supercharged Z please post if this helps because I know you guys have the same problem too and If the remedy is the same then we've found the cure. All in all I'm glad it was solved and I can sell the car knowing the next guy won't have to deal with this nonsense.

Thank you all for your support through this and I hope all you guys with this problem out there get it solved as well.

Figured I would chime into this as something similar happened to me tonight.

Jumped onto interstate and attempt to merge over into fast lane, apply some gas and my Z just stutters. Felt like I hit a rev-limiter or went into limp mode for no apparent reason. Oil temps are 195, no SES light present. My initial thought was I had a vacuum leak. The only thing I've done recently was dropped in a new set of Black Hex R2C filters. I get home on an open stretch of road and go WOT with no problem.

Car has 106k miles. Spark plugs recently replaced.

Same thing happened to me with the Stillen SC TB extension cable.:shakes head: My shop was able to diagnose and repair the faulty pin/connection and so far it's been ok since. :driving:

Thanks to all for writing. Have not written much since i have no update. taking the Z to another dealer on monday for a second opinion just to be sure the first dealer wasnt trying to eff me over because of the problem i had with the service manager. If it turns out to be the TBs, i found reasonable priced hitachi ones on amazon or i might go with synolimits ported TBs.

Lets see what happens... :confused:

Finally got my car back on friday, turns out fuel lines were broken :mad:

Apparently, the paint shop that worked on my car a few months ago broke the lines while lifting the car when they removed the door and fender :shakes head:

Obviously, i have no hard evidence of this, however i do have a good relation with the owner of the shop, so ill be talking with him this week to explain what happened. :ugh2:

Anyways, just wanted to update you guys on this, since it seems that fuel issues also cause the same behavior in our cars as with air intake related issues.

I've got the same throttle hesitation issue after stopping at the lights for a few minutes and taking off in 1st gear. I will also try to clean the throttle bodies and hopefully fix the issue. Thank you all for posting your issues and the fixes you had. This is why I love this forum. Everyone is happy to share their experiences and happy to help.

:tup: thats what were here for!

For me, besides this last problem, its either been dirty TBs or crappy 91oct gas. Also check/clean maf sensors, carefully, they get dirty after a while, especially if you have K&N oiled air filter like me :tiphat:

2nd time in the shop for this GOT VIDEO THIS TIME
 

okay guys this is the 2nd time in the last week my car is in the shop for the same thing. Last time I was in there they told me they cleaned off the throttle body position sensors since they could not find a particular code stating the problem and since I had no video proof I took that and went on my way. This issue always starts out the same, ill get in the car start it everything seems normal I take off try to accelerate in 2nd nothing at all. ill finally get up to speed to go into 4th and then ill try to downshift to 3rd and when blipping the throttle I got no response AT ALL. repeatedly over a 10 minute period so I made 3 videos of it to document the problems and show Nissan exactly what's going on. They have provided me with a rental car for the day while they figure it out. This has been an on and off again issue for the past 5000 miles or so on my car, which is a 2014 base model 370z with about 36k miles, with Stillen HFC, Nismo S-Tune Y pipe, and AAM Short tails I have video I will post up once it gets uploaded to my google one drive. If anyone watching the video has had identical problems please comment or post.

Video as promised
 

here is the link to the video of this god awful problem please comment/reply if you have been through this situation. I'm not sure but I believe Capstone law is filing a class action suit for this issue as well as the CSC failure which I have already been through once on this car as well so any comments or reply's will be useful for them

https://drive.google.com/file/d/0B9P...ew?usp=sharing

Has your car gone into mode at all?

Just out of curiosity, is this issue isolated to manual cars only? Becouse from the previous posts none of the cars list an automatic car under the type of cars they drive.

Just like P' Z, MikeUCFL, juld0zer, carlitos, kangstar, Digltonium, Kabestro, mike12002us. They all seem to have manual transmission cars.

I wouldn't have thought so.

What is the part number for the cable, and where can I find the insulated one? Thanks!! :driving:

I always thought it was throttle related because i had a bug in my throttle map that would only randomly cause the severe lag where the revs increase extremely slowly. My guess is that the TPS or the throttle body itself would age or gunk up slightly. ECU figures commanded vs actual position isnt right so it goes into limp. After all, these cars emerged around the time of the Toyota floor mat scandal.

The thing that puts me off your overheated TPS theory although you have proof that i don't question is that from factory the throttle bodies are connected to the engine's coolant circuit to warm and stabilise their temperature. Largely to prevent icing but perhaps also to keep them from overheating. In their default location they are subject to coolant temps around 90*c and above, and also convective heat from the headers/cats beneath.

The Stillen kit places the throttle bodies on the hot side of the intercooler. I cant remember if the coolant plumbing is retained? So maybe the coolant really is there to keep them cool?

Personally, i think yours might be an isolated case where something failed and melted the wiring.

It's easy to upgrade this cable - wrap it in exhaust wrap and then some foil tape on top. Alternatively you can buy heat insulation sleeves for ignition leads which will do the job too.

Just had something similar happen for the first time today:

2014 7AT 41k miles, FI exhaust + K&N drop ins. Cold start, everything seemed fine until about 5 minutes later the car would not go above 4k rpms. Basically no power, a PRIUS would be faster!!! No CEL either.

Now at home with a loaner awaiting the bad news...

So I gather they will try the following:

1) Blame the k/n filters, clean the MAF sensors, coin-toss if it goes away
2) Problem will return, then they will clean the throttle bodies and/or replace.

I have the extended gold warranty or whatever the hell it's called.

Never once had a single problem with the car up until today