Tune or install problem?

EVOHUNTER

I purchased a stillen v3 kit, it was installed. I used the stillen can tune until i was able to get a proper tune. After the tune - get power! getting great boost. Still have a hot start issue, which is easly fixed, but my main problem.
My idle - it'll dip low on the rpm, but this happens when my car drops my AFR to about 10.5 at idle. It jumps around and doesnt sit still. Should it idle at the same afr? everytime? Also coming up to a light do 40mph, take the car out of gear and coast to the light, my afr drops to 10 and will bog out inless i give it a shot of gas, then it jumps back to 14-15afr and idles fine. In colder weather, car runs great, does the idle thing once in a while.
So considering the stillen can tuned never idled bad, just had no power, im leaning towards the tune? Thanks in advance.

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Boosted Performance

This is all in the tuning. I assume you got it tuned at LS by Cam?

I had a 350z customer with my ST kit over last night for some vac. line repair, and his idle a/f was all over the place. From 13:1 up to 18:1 and surging. That is not right at all. It is just another example to support my theory on tuners in Alberta.

This car was tuned at LS by Cam.

EVOHUNTER

You are correct, LS did tune this car.
At first i thought a vaccum leak, I used my leak finder/smoke machine.
No vaccum leaks. It'll surge, but from 10-15.1 at idle.

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vividracing

If the only thing that changed was the tune, and now it's acting weird... I'd bet it's the tune.

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EVOHUNTER

the tuner is blaming it on a vaccum leak, I dont have a vaccum leak anywhere, exhaust mani, cats and exhaust are not leaking. All vaccum hoses are fine and fittings are fine.
I think ill have to bite the bullet, and wait for a better tuner.

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Boosted Performance

Heard that before....and it is never the kit/install (whatever brand it may be). If it was a vacuum leak it would be constant, and you would not have the constant change in a/f.

Now you see why I wanted Vince to come up here and tune all the UpRev cars. Too bad (for all the Uprev users) it did not work out.

kellyefields

I know exactly what is going on here. the problem is the placement of the intake filters and how close the MAF are to the filter. there is a little plate that comes with the kit that is supposed to block air/water or whatever from directly hitting the filters, if you are missing the plate like I was I would get the AF jumping all over the place and it would create a limp mode issue. Here is how you can tell if this is what is happening when tuning and you have the fan on in the front of the car for cooling turn the fan off and see if the air fuel settles down. then turn it back on it will jump all over the place. then put a piece of cardboard in front of the filters to block direct air and try it again and you will see the difference. My fix was to turn the intakes around to fit under the drivers headlight in that dead space so they could get air when needed but be shielded from direct air intake.

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MY 2009 SC BUILD.

EVOHUNTER

ill take a look into this, i know the plate is there..
ill try this fan technique, hopefully this works.
thanks man!

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kellyefields

This should help you get a good tune under your belt. what happens is especially when you are using a fan to cool during a tuning session it creates a ram air effect. when the car is not under load (ie giving it gas) the engine does not require a lot of air flow but the cooling fan basically force feeds the engine air causing the crazy numbers. Take the fan away you get a more accurate reading when not under load. So try shielding the air away from the filters and you should be ok. I just decided to take it to the next level and move the filters off to the side to prevent this effect. it allows the filters to get the air they need without blocking the air flow going throught the front of the car. I am not sure if Stillen realizes this problem but in some way I think they did and that is why there is that deflector on there but when you go to do a custome tune and are using a high output fan to cool it creates havoc and causes these problems. Mine consisted of the car when crusing at high speed the air is forced into the engine causing a limp mode of sorts and when I would fall under 2500rpm it would not allow me to go above that until I turn the car off for 30 seconds to reset the computer. It also caused multiple misfire codes and bank to rich codes to pop on mine since finding this out I have not had any of these problems since.

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MY 2009 SC BUILD.

EVOHUNTER

thats crazy man, i had the same problem, same codes.
My car did it few times last year, went into limp, all lights came on, shut the car off, then back on. and it ran fine.
I had some throttle body code.
So now since my car has been tuned that way, if i make that filter adjustment, like u did.
Is it going to run better or am i gonna need a new tune?

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kellyefields

it really depends on how the tuner did his tune. I would go to the tuner and explain to him what I have told you and he would be able to confirm if you need to be retuned or just tweeked a bit. I am glad I could help. I think I will do a sticky on this subject if I get the time.

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MY 2009 SC BUILD.

EVOHUNTER

i wish that went through!, we need someone who knows there way around the Z!

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