SCANCHECKTHIS

Ok, I have searched, I have only come up with a few answers for the issue. First of all lets start with its an 06 rx8 base model with 6speed. It has a greddy mass air flow sensor housing with a 3.5" cold air intake so we have a change from the cai to the maf of a half inch. Next is the car ran fine with both of the maf housing (stock and greddy). The car has 36000 miles and has had its fluids changed every 2500 miles, every 10000 has been a mild cleaning with seafoam, and a full carbon clean at 30000. The problem devolped within the last 1000 or so miles and is like a detonation sound, kinda marbles in a can sound at 4000 to 4500rpms. I just did the major 30000, checked to make sure the coolant had no system leaks at cold and at temp. changed spark plugs every 15000 miles, just changed the fuel filter at 30k. Oil is good colored and has been even been pumped out as much as possible to get as new as possible every 10k. the only thing I can figure is that the spark plug wires or coils have gone bad, as i changed back to the stock maf housing and air box assembly. It has a catless mid pipe, hks hi power exhaust and no check engine light since putting the resonator on the catless mid pipe. Thanks for any help
Daniel

dannobre

iTrader: (3)

How did you change the fuel filter? Your coils and plugs could be a problem at 30K
I'd start with the plugs

SCANCHECKTHIS

the entire fuel pump was changed as it went bad around 31k so that, i just did new spark plugs. i did get a reflash at 30k as my car was running great on the reflash it came with, after the reflash, it had hard starts, poor idle. It just seemed to go to hell after that flash. I do 99 percent of the work myself if I have the time. The first two services that i went in for, mazda of escondido left both leading plug wires off, so it ran on the trailing plugs and the second was at hoen mazda and the left the oil cap off. So I do all my own work and check my codes with my dealerships scan tool. I can't figure it out, its not recording any codes being thrown?

swoope

iTrader: (5)

check the shielding on what ever you have for a mid pipe. i had this happen a while back. at 3800 to 4200 it would make this odd raspy noise.. one tack weld later gone.

beers

SCANCHECKTHIS

you know I wish it was that, but its a full hesititation at 4000, chugs and pops and pings. I tried to describe it as best I could, will have new coils tomorrow morning and will know one step closer if that is the situation. I hope to figure this out, this has been the best car ever besides the lack luster fuel milage, but thats why I have a motorcycle.

swoope

iTrader: (5)

that is about the time for coils. i missed the hesitation part..

have you had any flashing cel.

btw, i have a set of the newer design stock coils that have less that 8k miles on them..

pm me if interested, and btw, you should put your location in your user info..

beers

Old Rotor

What octane fuel are you using? Have you changed air filter?

SCANCHECKTHIS

well I already ordered the coils, if I had known I would have totally gone for it.
Thanks Swoope and Dannobre, If this doesn't work, I will start checking the intake manifold for any stuck valves. I think that is the second thing to check tomorrow morning. And there are no vaccumm leaks, checked all the plumbing over the weekend a few times thinking I missed something. So if these two are fine, its off to a compression check and Not one single cel at all.

SCANCHECKTHIS

91 oct only, shell or chevron only

Mazurfer

Go with Dannobre here based on what you've said................plugs, followed by coils(my personal bet), and then maybe wires.

DOMINION

If you have new plugs but you flud it you will have faulty plugs. So when you chage the coils check the plugs. I would also change the spark plug wires too.
However, there is a plug on the T.B. and when you remove your stock air box to install a K&NVII or CAI you have to plug it IF you remove the VFAD. If not your car will hesitation then stall.

SCANCHECKTHIS

yeah, I have that nipple plugged off the t.b. coils just got in so we will see. Thank you guys so much, I will let you know what I find out exactly.

Razz1

After the coils............

Check the nipple. Just because it is on doesn't mean it's not cracked and leaking.

SCANCHECKTHIS

coils replaced, still a hesitation, put new vaccumm cap on nipple, nothing changed. So removed the upper intake manifold, lot of residue inside. cleaning it and going to mazda to have the compression checked.

Brettus

iTrader: (2)

perhaps the secondary shutter valve is sticking ?

dannobre

iTrader: (3)

If the nipple is leaking...it will throw a CEL after a bit for fuel trims

Jon316G

iTrader: (1)

+1
If you removed the intake manifold extension and saw "residue", it could be a stuck SSV valve.
Try to open/close the valve.
Either move the shaft connecting the actuator to the valve by hand or use a hand vacuum pump connected to the actuator.
I use a hand vacuum pump from a brake bleeding kit when I do mine.

dannobre

iTrader: (3)

There is an updated breather vent system that fixes this.......

SCANCHECKTHIS

Ok guys, you can all give yourselves a pat on the back, I thank you all. Secondary shutter valve was sticking until 4300, Now what has me concerned is that the ecu never logged any codes during the last week. So while at mazda today, there is an actual reason why to seafoam from the nipples instead of the spark plug holes or so says the tech I talked with. If you clean at the spark plug holes, it only cleans the combustion chamber and not any of intake tract, I thought the secondary valves were above the nipple points? Well this is why I only take care of the damn thing, I refuse to go any futher with modifications, and after this I don't really care to dive into the intake manifold again. Thanks all, for all help you have given and the suggestions made.

Brettus

iTrader: (2)

I don't think you can clean the intake tract that way .
If you have gummed up ssv then the vdi and Aux ports will probably need attention as well .
I would fit a catch can vented to atmosphere to prevent the same thing happening again .

DOMINION

Dibs! sell me your coils

SCANCHECKTHIS

now that is what I thought. I cleaned the whole intake tract yesterday by hand, relubed the secondary and aux valves. cleaned the tb, Drove it for 3 hours and decided it was the secondary. Catch can is my next item to buy.

9krpmrx8

iTrader: (46)

Huh.

04RX8man

93 Shell

horsemen

Would a stuck SSV cause errors or a CEL?

I ask because I am having similar issues.
Rx8 2004
hesitation around 3800 RPM
idle isnt horrible, drives fine up until 3800RPM
No CEL, not even a flicker since the hesitation started.

The only thing I can think of that may be related.. maybe not. I drove in some crazy rain about a month ago. my CEL came on for misfire. I had to deflood the car twice after it quit raining. after she sat in the garage for a day and dried up she has been running great since.

Ran great until about 2 weekends ago (bout a months time) Saturday the car ran perfectly. Sunday I fired her up and hesitation began.

Relaced the CAT already.
Plugs, coils, and wires replaced before the rain, but have not been replaced after.

Like i said no errors at all
So possible a stuck ssv?
the plugs look like they are in good shape, but may be worth replacing anyways?

Thanks for any help in advance
Dave