Redline Cowboy

Its a 2004 GT. I haven't had any issues with it and I've had it about 3months.. 56K on the gauge. I haven't done any major modding but.. I did Remove the VFAD and capped the nipple on the TB. It seems to bog down when i come to a stop.. the tack bounces between 500 and 1500rpm.. when it starts it hoops up to 2000 and sits there for about 3mins then drops to normal idle at 750. Although I have seen a smooth powerband in the rpm range while accelerating. No issues while driving.. but.. it is pissing me off.. I have done the 20 pump on the brake to reset the PCM and the triple tap to quick set.. but nothing works.. my intake box still has its stock filter is this the problem.. Or what.. please help..

Mazurfer

When did you remove the VFAD......real recently? It's hard to determine exactly what time frame this all has occurred from your post.

If you really wanna do a good reset, then disconnect the battery for a good 15 minutes. After this you will have to reset the DCS/TCS and the car might run kinda rough and want to stall for about 2-3 drive cycles as it re-learns the fuel trims.

Again....I can't tell from your post if you are seeing this idle problem just due to the reset or whether or not it has gone on more than 3 drive cycles after the reset.

DCS/TCS reset =
Turn car on, but not start.
Turn wheel ALL the way to the right, then the left.
Turn car off.....wait a few seconds.
Start as normal and DCS/TCS lights should go off.

Redline Cowboy

[quote=Mazurfer;3374565]When did you remove the VFAD......real recently? It's hard to determine exactly what time frame this all has occurred from your post.

If you really wanna do a good reset, then disconnect the battery for a good 15 minutes. After this you will have to reset the DCS/TCS and the car might run kinda rough and want to stall for about 2-3 drive cycles as it re-learns the fuel trims.

Again....I can't tell from your post if you are seeing this idle problem just due to the reset or whether or not it has gone on more than 3 drive cycles after the reset. quote]

I removed the VFAD about a week 5days ago. and I haven't disconnected the battery yet but will..

The first start or if its been sitting for about three hours or more it revs up to 2k and then drops to about 750. once at 750 it gives a bounce between 1000 and 250.. just before stall.. even the battery light blinks and least onces.
Now if still warm the idle likes to drop and bounce for about 5 to 6 seconds then levels. when I come to a stop it does the bounce too.. and the funny thing is.. there is no engine light on..

0 issues once moving.. only if the clutch is in and the rpms go down. stopping and start up..

Redline Cowboy

I also have some cheap home built intake.. A big filter and piping.. specture junk.. I was bored.. If disconnecting the battery resets the PCM and makes it relearn the air fuel. then If I put that on.. will it re tune to that or should I leave it off and keep the stock box.?

bse50

Try with the stock intake...

mikekey

Did you also do the tripometer reset?

Flashwing

Yep, if you built a home made intake that is either the cause or certainly making the symptoms much worse. Even if the PCM can releard the fuel trims it will still cause some problems.

I can promise you that you're not getting any better performance with the intake you have and the stock intake will perform just fine for the car.

Jon316G

iTrader: (1)

This will not achieve anything.
The car doesn't care how many miles the trip meter records.

Agree 100%
I don't understand why people buy a car like an RX8 and then try to create home made intakes that will never perform better than the stock.

mikekey

Let me rephrase, there are two procedures to reset/clear the pcm. The first involves the trip reset button, the second involves pushing the brake pedal. If you did not reset both, it could cause rough idle. Just a thought. I did the VFAD removal 3 weeks ago, reset using both procedures, idles just fine. Also, just added K&N drop in a few days ago and that did seem to smooth out the idle even further.

Jon316G

iTrader: (1)

Wrong

Jon316G

iTrader: (1)

Let me explain further now that I'm done eating

Holding the odometer button only takes you into a diagnostic screen.
You can read about this in a thread I made:
https://www.rx8club.com/series-i-do-yourself-forum-73/diy-diagnostic-outputs-155947/

To understand the correct way to clear the KAM and NVRAM, read through this thread:
https://www.rx8club.com/series-i-trouble-shooting-95/real-way-clear-memory-169443/

mikekey

How so? A complete sentence with an explanation would be much more productive rather than "wrong"

Jon316G

iTrader: (1)

Already did... look at the post above yours

mikekey

Okay, glad for your explanation. Here is the thread that I read about this procedure. https://www.rx8club.com/series-i-tech-garage-22/ecu-clear-reset-27548/?pp=15. The guy had a problem with a procedure I am familiar with, whether worthless or not, I'm just trying to give him some ideas. Again, I did this and have no problems with idle. For what its worth.

Jon316G

iTrader: (1)

No problems... that is a common misunderstanding and I wish that old post would be updated.

Redline Cowboy

ok.. to clear everything up.. the homemade intake is not being used.. mainly cause i didn't like the fact that it has a loss of power in the lower rpm and it just plain didnt like it.. so with the VFAD mod and it capped off at the TB.. I have the stock intake box in place.. just to clear it up I am not using the homebuilt.

Update..
Idle has cleared on its own.. about about a week of rough running it fixed its self.. But.. The start up is still pretty weak.. takes about 4 seconds of attemting to turn over before it starts. and thats with a little bit of starter grinding sound.. I'm thinking it could be the starter.. but Idk.. I have read in other posts that the starter in the car is weak and underpowered for the RX8.. If this is the case what is the rate the dealer will charge for this to be fixed or replaced.. cause I am half tempted to take it in.. a little worried about the VFAD mod being seen and them not wanting to work on it.. But.. then I can say that it was like that before right.. or should I replace the VFAD and go through the whole removal and rough idle all over again..

BTW.. thanks ya'll for the bit of help.. i was going to disconnect the battery today.. but since it isn't idling funked up anymore I see no need..

Positive feed back fellas.. No more fighting.. Lol..

mikekey

Hey Redline, start up on mine is a little weak too (07 w/ 38000), especially on cold mornings. Always cranks, just seems to struggle a bit. I am going to step out on a limb here even with the fear of being scolded (j/k Jon316G) and say that if I were to take my 8 to the dealer, I would not go through trouble of putting it back in. Now please correct me if I am wrong but from what I have gathered on this site, the VFAD was put into the 8 for the sole purpose of noise reduction. I see no reason any logical dealership (if there is such a thing) would take issue with its removal. If that were the case, almost all 8's with aftermarket intakes would be disqualified (as all but 1 or 2 disconnect the VFAD, at a minimum) and there would be a lot of unhappy Mazda customers.

Glad to hear your problem has been corrected.

Jon316G

iTrader: (1)

No scolding today Mike
I probably wouldn't bother putting the VFAD back on either, but keep in mind some dealers are worse than others in that they look for anything to blame so they don't have to warranty work the car.

How old is your battery.
You have an '04 which has the weaker starter.
If you don't have the upgraded starter, I highly recommend it.

mikekey

Jon316g, off topic a little but whats your opinion on dropping the RB REVi Ram Air Duct on a stock box with a K&N drop-in, worth the extra $ or just leave it alone?

Jon316G

iTrader: (1)

If you have the itch to upgrade your intake, I would say that is one of the best options next to an AEM intake IMO.
But realize that no matter which method you choose, don't expect a noticeable gain in performance... only a gain in sound.

Redline Cowboy

well i have no clue about battery.. i was looking at getting an optama or what ever.. and the starter .. hmm.. thats pricey..

mikekey

Thanks, not sure I want it any louder. I was thinking that adding the duct might actually quite it down in the cab a little. Regardless, I rather spend money on performance, not sound. Guess springs will be next.

Jon316G

iTrader: (1)

I have an Optima and the upgraded starter on my '04... MAJOR difference.
Well worth the money.

jzamarripa

I had a similar problem this past weekend. The car would shut off when I would press the clutch and put it in neutral, no sputter though. Then the car would not turn on at all. I bought a new battery and it stayed the same. I removed the airbox, throttle body, and the upper black plastic piece and cleaned the weird valve in the tubes going into the rotor housing with seafoam deep creep. After I put everything together the car started right up and is running with a smooth idle and no more shutting off. You should look into it.

Jon316G

iTrader: (1)

^oh boy... while its good advise to consider, we should eliminate the common occurrences with his symptom before going as far as a stuck SSV causing this.
Plus... a stuck SSV wouldn't cause starting issues, but can cause your idles to act weird (even stall the car).