Hissing noise after turning off car

[Coop]

Hi, so I am recently installed 1320 headers, overpipe, front pipe, and drove it, and the overpipe was rubbing on the frame so I fixed that and now whenever I turn off my car I hear a hissing from the airbox, like air is blowing the wrong way...
Is one of my header gaskets leaking or something?

Video to what im talking about:

-Coop

Edit:
I am also running Stage 2+ E85 tune on the OFT.

[FRSBRZGT86FAN]

Originally Posted by Coop

Hi, so I recently installed 1320 headers, overpipe, front pipe, and drove it, and the overpipe was rubbing on the frame so I fixed that and now whenever I turn off my car I hear a hissing from the airbox, like air is blowing the wrong way...
Is one of my header gaskets leaking or something?

Video to what im talking about:

-Coop

Sounds like you're throttle body is opening and closing.


You wouldn't happen to have a tune yet would you? Also that airbox lets you hear things you wouldn't normally hear

[Coop]

I do have a tune. the stage 2+ e85 on the oft. would that make a difference?

[humfrz]

Originally Posted by FRSBRZGT86FAN

Sounds like you're throttle body is opening and closing.


You wouldn't happen to have a tune yet would you? Also that airbox lets you hear things you wouldn't normally hear

That very well may be it, right there.

I wouldn't worry about it.

Unless it backfires, blows the air cleaner off and starts a fire -

(jest ah messen wich ya)




humfrz

[FRSBRZGT86FAN]

Originally Posted by Coop

I do have a tune. the stage 2+ e85 on the oft. would that make a difference?

Yea it could be injector pulsing or a self check thing, datalog the car on the Stage 2 93 octane tune and post the logs here on datazap. Flash the Stage 2 93 octane tune, and drive around for a day or so then datalog after the car has had a chance to acclimate. Do some pulls and make sure you make sure its recording these parameters for the log:

MAF Voltage: Voltage of the MAF sensor. There is a table that converts this voltage to g/s that the ECU then uses. This table may need to be configured to your sensor.
VVT intake: The angle of the cams of the intake VVT system
VVT exhaust: The angle of the cams of the exhaust VVT system
Ignition advance: Do you mean ignition timing? The angle before top dead centre (BTDC) that the sparks ignites in the cylinder. Too much advance and you'll get knock, but generally the more advanced you go then this increases power.
KC learned value: The ECU has a base ignition table, and an advance table. The KCL value is how much timing the ECU is adding onto the base value from the advance table. If the KCL values = the advance table then the ECU isn't pulling timing and all is happy.
STFT: This is what the ECU adds/removes from the fueling as an instant response to the target AFRs while in closed loop.
LTFT: Multiple occurrences of STFT will result in LTFTs being applied. Both LT/STFT are done on load based so you don't get a consistent reading across the full rev range or from different pedal positions. You ideally don't want massive swings in LTFT, STFTs aren't necessarily an issue.
Adv multiplier: The easiest way to describe this is the multiplier of the ignition advance table: Base ignition timing + (Ignition advance timing x IAM) = Ignition timing. FYI, Ignition advance timing x IAM = KCL. This will vary depending on knock detection. It will drop if consistent knock events are detected. It won't however necessarily drop upon every detection of knock.

Throttle percentage etc.


http://www.ft86club.com/forums/showt...01#post1842501


When you post them we can read the logs and see if you have an exhaust leak or other issues

[xwd]

I'm using a different throttle body setup on my car and I get something similar after shutting off the car and I would guess it's related to the throttle body. I haven't been able to have someone else drive the car yet so I can try to diagnose it but hoping to do that this weekend.

[Coop]

Let me know if you figure out what is causing it

[strat61caster]

Sounds totally normal to me, I agree with throttle body actuator, probably just doing an end of drive calibration and reset.

Might also be fuel system depressurizing, you'll hear a similar noise before starting the car.