Supercharger Starting/Idle problem
 

Well, flame suit on first...

Yes Stillen kit is hated by people in here due to their design flaws and maxed out power etc...

Well I got the kit and I've been happy with it... sort of

Trying to improve the Stillen kit, I did the followings

1. Custom water to air intercooler (Thanks to ANMVQ for the part info)
- Due to Stillen's heat exchanger's size being too small

2. Custom tune
- Stillen tune was running wayyyy too rich and was not friendly to my mods (Greddy Ti-C with silencer, Berk HFC)

3. CSF Radiator
- Wasn't done to improve the Stillen kit but I put it here just so that everyone knows that it's there.


Now here is the problem

When starting the car cold, it has no problem starting. Starts strong

However when warm, 3-4 times out of 10 times, it would do something like this. (Skip to 00:35)

The start sounds weak and sometimes the car struggles to start the motor. It also cranks a bit more than usual sometimes. When it stalls the Rev sweep does not happen

Now I got the habit of giving a little gas while starting the car just to make sure it doesn't stall on me :icon14:

It could be the tune, but i've been there 2-3 times to check on my starting issue and after they make small adjustments it starts fine when I'm there. :bowrofl:

Now the idling issue.

With a little research, most of the SC kits suffer a small idling problem even with a custom tune. It looks something like this. (Skip to 00:39)

Now mine used to do that these days and I stopped caring since the RPM would just bounce up itself. It was driving me nuts for the first few weeks. However last night, when I was stopped at a redlight, it stalled. I then realized my car stalled and tried to start my car right away. It took quite an effort for the motor to start my car and I had to give gas to properly start my car :ugh2:

Few theories on top of my friends after having a little chat with buddies. We were looking for a solution to 2 problems "starting/idling"

1. Spark plugs?
- Maybe 1 step colder might help the car starting problem...
- GTM Motorsports*::*IGNITION SYSTEM*::*NGK Iridium Spark Plugs - VQ One Step Colder

2. Tune?
- Custom tune may take several adjustments to make it right.
- Oh btw, my A/F ratio is usually at 14.4 at idle. Can anyone with stillen kit chime in?

3. Leak?
- I doubt it is... but who knows :stirthepot:

4. AC?
- I believe AC does not disturb anything.... but I did a little testing driving with AC on and AC off. When AC off, the idle is a little more gentle and smoother than AC on. When my car stalled, I had my AC on. :icon23:

Any inputs guys? I would really appreciate any help

:tiphat:

And.... I just saw this. I may have to go check my car from my tuner.

http://www.the370z.com/forced-induct...gine-fail.html

If it makes you feel any better whatsoever, before trading my Z it did that. I just had an intake and exhaust.... I know it's nowhere near the same setup, but my rpms would do the exact same thing. The car would shudder also.

Hey man ! You are very welcome. Have the answer for this too. LOL Mine did this a few times also. Its the HOT start and idle set on the tune. My First issue was mine wouldnt start after it was warm, Too much fuel( hot and cold starts where set the same?)
I had one step colder plugs too, along with bigger injectors, My tuner ironed that out if 20 mins :)


An to be really honest. I LOVED my Stillen kit, Wish I could have kept is, The 457WHP is made was MORE Than enough for me.

Yeah, if the hot start settings are dumping in the cold start enrichment, you'll idle like crap. I would hope the OP's tuner would have known that. Oh well, it should be an easy fix. As far as spark plugs, a lot of us are running the OEM GTR plugs with no issues.

No wonder I smell fuel after a couple rough starts. I thought the injectors were leaky and flooding the cylinders. Well, I was hoping GTM would send me an updated tune after giving them my logs. It has been over a year, and I never heard back. I'm still running the out of box tune. This is something I've been dealing with for the past 1.5 years since owning the kit, and I also give it some extra gas so it snaps out of it.

[OFFTOPIC]Ditto on OEM GT-R plugs. I'm thinking about HKS for my next set. BTW, are the gap specs the same as stock? [/OFFTOPIC]

Paul at Baker had to harass him pretty good for my updated tune. When it gets a little cooler I'll just take it to Kosmic and get it dialed in all the way.

Jason and Paul said the HKS plugs weren't better enough than the GTR plugs to warrant the extra cost, but that's all I know about it.

I would get that done sooner than later. You do not want to wash out the cylinders. :/

Me or Digi? I've gotten an updated tune from Sam, i just think there's more left on the table as well as some part throttle stuff that could be better.

I am having a similar idel drop issue, getting a full new tune done by Kozmic in Houston tomorrow finally. They are aware of this issue and have told them this is basically 90% what I need fixed.

I just had an issue with my Stillen kit, but not the same. First the engine light came on after running hard for about 5min. Also would always idle with a constant 300-400 RPM swing. I took it back to Stillen to get fixed and it was one of the throttle bodies sticking. So they replaced it under warranty and ran great.

Then I started having a hard time starting the car. It would always start, but take a few cranks to fire up. And then kinda sputter to get going. So I took it back to them and it was a small pin hole in the fuel pump fitting. Keeping it from holding fuel pressure. They replaced the hose and all has been good since.

If you can try to read the code with a reader and then you will know where to start looking. Also you might try to turn the car to the "ON" position for a few seconds without your foot on the clutch. Then turn the car off. Then you can try to start it. Hope you get the issue resolved soon and get your Z back on the road. Keep us posted with the results.

Glad you cought your fuel issue, They didnt listen to me and motor blew up becasue of that. :/

I'm kinda lucky because if I ever have an issue I can go straight to Stillen and drop off my car. They did the install and gotta take care of it.

Sorry man LOL Digi. :tiphat:

I know mine has the idle issue and then will throw a P0174 (bank 2 too lean) and then just idles at 1k.

I don't have any idle issues, afr 14.3-14.9 idle speed 800-825

Good luck with your problem.

I tried, sent logs, and I never heard back from them. I think I stopped getting any support from GTM since the Hallman Pro RX installation at the dealer.

My car was with Baker for over a month, and I was expecting for a tune. All I got was the out of box tune when I picked up the car. I don't think they had time to get it dyno tuned.

So I'm assuming the initial white smoke I see once in awhile when daily driving is excess fuel since the test pipe installation? :ugh2:

The nearest tuner is Modifed by KC (MKC). Next would be some place in Dallas like JoTech. [shrugs]

Well sorry about the non support from GTM( not suprised) Just my .02 tho..

But I would really take it to ge tuned and fix that issue, they may be other things going on. You do not want to end up like I did. An my tuner was really adamint about me getting to him when I was having the start up issues. Washing the cylinders is a serious concern. White smoke anytime is not good,

The white smoke doesn't happen often, and it's usually when I get moving after a cold start. Some reading points out to to condensation. Other than that, my oil and water reservoir is good. Next oil change is coming up next week so I'll see if there's any fuel smell in the oil. I've only had the test pipes installed for about 3 months.

I had the hot start issue well before the MBC installation, and I pressed on trying to get updates from GTM. No response. It has been 34k miles since the installation, and I dealt with this almost everyday. Starting to feel the rough idle lately as well, so I might do a compression test the next time the spark plugs get pulled. So I'll try to do some sanity checks before getting it tuned since the goal of switching to a 3" exhaust setup is a bit distant.

That's most likely the issue.

Just dropped my Z off, will see the results if they can fix it today. :tup:

Thanks for the responses guys ! I really appreciated.

I will keep you guys posted once I go see my tuner next week :)

Guess I'll have to make a 10 hour trip to visit you guys again eh? The EX is totally out of the picture, so I'm all for some responsible drinking in Htown while getting my car tuned haahah.

Hope you get your issues resolved. I will need to make sure my tuner works out the hot/cold idle and start issues before I pick up the car. Let's see how he does with 850cc injectors.

My Sentra has hot start issues, turns out its a faulty fuel pressure regulator. After you car warms up and then starts to cool, pressure drops and you have to crank it, stop and re-crank to start it up. Works every time but it's annoying.

Let us know when it gets fixed.

The car now has 70,000KM and that Stillen Sc kit may be stressing the engine with old spark plugs. My car is going to for a tune check up sometime this week.

I have some questions for experts in this community :)

1. Spark Plugs: What system, or brand do you guys use for FI application? Anything one step colder than OEM ones?

2. What's the a/f ratio range when the idle is unstable. For me, it was 13.5-15.2 surging up and down while RPM needle struggled to keep the car running. When stable idle, it usually sits at 14.4-14.7

3. Do you think SRM affects the idle RPM speed? I remember my tuner saying he set the RPM to 800 to 850 ish but I sometimes see stable 700-750 :/

VERY CONFUSED

Plugs one step colder,GTR plugs work well
AFR should be 14.3-14.9 thats what mine is
Idle speed on mine is 800 b/c it is a 6sp

The idle surging up and down is b/c your tuner must tune the MAF @ idle instead of using the fuel comp table.

Thanks for quick response !

My car thought it would be funny to throw a random engine light :(

I check to see what code it is and if it is BS I shut it off with Uprev.:tup:

Dont have the reader here with me it idles high. 1000-1050.

Heading down to a shop first thing in the morning

Plus 1 for the GTR plugs I ran those worked very well for me, Sorry cant comment on the idle issue, I didnt get a chance to install mt AF gauge.

From what you guys are telling me, I might as well continue using the GT-R plugs. :tup:

What about those who are pushing in the realm of 525 whp and beyond (just in case I decide to join the 600whp club one day)?

Yea, I could find out about my tuners GTR, 585WHP and see if he still running is stock plugs, But I would bet he is.. :/

DING!
Got a good chunk of my re-tune done, need to change my plugs to finish some WOT tables, but we fixed all my problems. No more idle issues, SRM plays nice now when downshifting, and did some fan speed adjustments to help cooling (don't know if it has done anything).

BTW, does this tune resolve the slight engine blip on up shifts when it's cold?

Like a large blip up on the RPM range or small?
Will try to look tomorrow when I get a cold start.

An you drive the car cold, UG:ughdance:.. I always wait for it warm up a little.

I have not been able to get rid of it.

No, not to that extent. It still blips on upshifts even after it warmed up a little. I think once it starts warming up and the idle oil pressure starts dropping, the throttle blips go away.

It might be a safety measure in the car when it is cold or the engine is cold enough it does this to protect it from any harm that could occur.