i`v just installed my mod ^, and thats what happend with me :
1) RAAAASP (i`ll be stright with you guys ,,,i like it some how)
2) when i start my car the RPM drops down so much (and
it did shuts off twice)
3) there is stang sound in idel (fft fft fft)
4) butt-dyno ...i think i`v lost torque but to
but the sound is SO SICK i`ll post a clip today (hope i get the time)

any one face the same **** ?!! or any idea

 

I thought you aren't supposed to get any/much rasp with HFCs?

 

reset the ecu?

 

You can rasp with HFCs too.

 

Yep. It all depends on the exhaust + HFC combo. This is why many guys have spent thousands of $$$ trying different setups to find that right sound w/o getting that embarrassing rasp.

 

Sounds like you may have a leak at the manifold/HFC flange. Check your pipes for leaks.

 

Darkness,

Your description suggests a leak, but you may have something else going on that is causing the stalling. I've run open test pipes before and it ran perfectly fine.

Did you do anything else to your engine at the time?

What ever it is, it has to be something pretty significant to cause stalling. Are you getting any CEL's?

 

^+1
HFC + exhaust combos, ive tried 4 or 5 setups. None of them affect idle at all. I bet its a leak somewhere in the air tract caused when someone installed the hfc

 

And ^+1 to Plumpzz.

Stalling can be a problem encountered when something isn't done right on a plenum spacer installation. IE - Leaving a PCV hose unplugged at the bottom of the air intake tube will easily cause it.

It may be something as simple as that.

 

as far as i know , all i did is remove cats > install HFC ,i didn`t do anything with my engine ,i`m thinking that my car need to be at full service this could be something pretty significant to cause stalling ( and no CEL`s)
when i finished the installation i start the car there was no leek down under , i can hear the (fft fft fft) from the muffler only .
and for reseting the ECU , i`v unplugged my battery for more than 24 hours ,isn`t that how its done ??

 

To remove the cats you must first remove the air intake tube and unplug the PCV hose.

Is it still stalling?

 

i didn`t remove any thing to remove the cat`s
i did it the hard why i think .
let me check if by accedent removed any thing
do i need tunning ? my car befor i install any thing on dayno gave me ONLY 212 whp my friends z 232 whp ,i realy think my car is missing something

 

Tuning won't help a stalling issue but it certainly can help the power numbers.

 

will i`m sorry to say i`v had it , i`v looked every where
1) nothing wrong with the installation i didn`t do any thing had to do with the plenum .
2) i think there is a very low sound near the HFC (tst tst tst ) is that a leak ? and is this much of a leak can make the stall ??
3) and i checked low & so dark (i think that indicate need to do service at the shop ) again can this make the stall
4) NO CEL , and i did the ECU resetting procedure : nothing happened as far as i know i did it right ,when i was working in the car the the battery was unplugged More than 24 hours
tomorrow is my last time to check my z my self
please any suggestions

 

My car did that for awhile. It needed a fuel injection cleaning, which included the plenum and throttle body.

 

Well it certaintly sounds like you have an exhaust leak.
Fix that and we'll take it one step at a time.

 

i think i`ll do that ,thanx and i hope that your car did fine after that !!

i`ll do that also befor i do that ^ ,,,
i think i said that too much ,,,,sorry for that

Hydrazine thanx for your follow up with me that did encouraged me to order MD iso thermal spacer from you , i`ll send you PM

 

huh?

 

Yeah. To remove the nuts on the studs of the driver side catalytic converter you need access from the top.

Remove the air tube, and reach down to the nuts with a 2 foot long extention with a 14mm swivel socket.

At least that's the way I do it.

 

It seems a lot of 350z's idle very low, and low idle + disturbance in air flow system = stalling (sometimes). If you can't find another solution to the stalling problem, you should raise the idle with Cipher or some other method (Nissan dealer CONSULT tool etc)

Another thing to help prevent stalling is:

clean the MAF sensor in the intake tube using a spray MAF cleaner

clean the throttle body (I've heard carburetor cleaner works well)

clean/replace the air filter