Chris

iTrader: (10)

yeah its hard to say it will do that on a street tuned car but I can def. see the value in this.

Chris

iTrader: (10)

Scott, why do you have to make me lol

9krpmrx8

iTrader: (46)

, you should hear that sucker suck some air. If it was outside the engine bay it would actually work pretty good I think.

Chris

iTrader: (10)

paper filters are preferred in my opinion. I due have a nice large K&N filter that fits on my ms intake but I feel like it just gums up the MAF. I also am shy of using the K&N on the turbo. If the car was more of a weekend joy ride I would most likely through the k&n on but until I actually suck it up and go and get another car I am going to stay very conservative

9krpmrx8

iTrader: (46)

Yeah I agree and will run a paper filter. I found a nice paper filter that fits a Chrysler Sebring V-6 that is the perfect replacement for the AEM filter. It's $10.00 at O'reilly's.

RotaryMachineRx

iTrader: (1)

Hahaha that GM filter....


I thought the AEM filter was a dry filter, no?
I do plan on doing the AEM(MS) upgrade or at least building my own with aluminum piping and some silicon couplers but I believe that will mess with Jeff's tunes so I don't want to switch it up on him now.... but I find the GReddy stock intake is pretty decent as far as temps go while the car is moving... once I hit a red light though you bet they jump right up (probably a different story in a warmer climate).

9krpmrx8

iTrader: (46)

I'm not sure on the AEM/MS filter type but i thought it was a normal K&N (owns AEM) but either way it doesn't filter well and the differences in flow are minimal.

olddragger

iTrader: (3)

Now thats a damn airfilter
od

Brettus

iTrader: (2)

That's a TEXAS air filter

Chris

iTrader: (10)

they are dry filters not K&N oil filters

RotaryMachineRx

iTrader: (1)

Woooo +1 for me..... Yeah I have been looking into getting something to replace my GReddy Airinx filter, but I pulled it apart the other day and the inside of it still looked pretty damn clean, but i know that thing can't be a great filter.

9krpmrx8

iTrader: (46)

Okay guys, need help!! I have asked a few educated members here and all had great input but I am getting no where after checking just about everything recommended.

Here is the deal.

All of the sudden over the last few weeks when my car is cold it idles like crap and almost wants to die, RPMS dip to 750RPM and occasionally I get either the random misfires code or the cylinder 2 misfire code. In the past I have gotten the flashing CEL a few times when doing runs as well but no CEL at that time. So I bought new BHR wires (BHR kit has 30k on it) figuring I screwed them up some during a plug change. I replaced them and found the L2 plug was not very tight. I installed the wires and replaced the plugs and it didn't help.

After a minute or two, the car warms up and the idle smooths out and it idles like normal at 880-950RPM. It seems to run fine but there still is some power loss intermittently. I did a 3rd gear pull against grungepups car (stock 07' GT 6 speed) and he pulled on me pretty easy and there is some hesitation from time to time in the 6,000 RPM range and then it picks up again. I know my car and I can just feel it's not pulling like usual.

Since is seems like the engine is being choked I was thinking an exhaust blockage now of some sort, and the exhaust shop I use thought so as well. See the video of the exhaust rattle below. Thinking the resonator in the BHR pipe failed, I had the BHR pipe removed and put the stock cat pipe (working fine when removed from a 07' RX8) back on the car. Then the car sat for a few hours, I went to pick it up, go out start it, and it does the same thing, rough idle, wants to die, etc. Smooths out after a few minutes when it's warmed up.

I inspect the BHR pipe and determine the fastener studs are rattling but the pipe and resonator appears to be in good condition and doesn’t rattle when tapped. And of course the car is idling poorly when cold with the stock cat pipe on so the BHR pipe is not the culprit.

Okay, so my next thought is that possible the mufflers in my Turbo XS catback are clogged or something. I waited a few hours and disconnected the rear section with the mufflers from the center section and start up the car. Same thing happens.

So, I put it all back together, uninstall the Cobb AP, do a battery disconnect, start it up, and same **** happens. So I go out for a drive after it's warmed up and she seems to be running fine, idles fine, pulls likes normal when accelerating, etc. https://www.rx8club.com/images/smilies/dunno.gif

I have 30k on a reman (vacuum at hot idle is 15-16), BHR kit with month old wires, plugs are a month old (verified wires are connected and tight), BHR fuel pump (fuel pressure gauge shows solid 60psi), intake is stock and OEM filter is new, no vacuum leaks (searched for hours testing anything I could, purge valve, SSV, etc.), cleaned MAF (also swapped with other RX-8 MAF), cleaned ESS, and just filled up with fresh 93 octane fuel. The only known issue really that was around before this started happening is my SSV actuator rattles at idle but vacuum test verify it still works.

Charles thought that I may have an exhaust leak at the header. That made sense since not too long ago I put the racing beat block off plate at the header to replace the air pump hose. Well, this morning I checked all the header bolts and the Racing Beat block off plate and all were tight.

I started the car, same thing happens. I feel all around the header for exhaust leaks and look for discoloring and other signs of exhaust leaks and see nothing and when laying under the car you cannot hear any obvious exhaust leaks and I saw no cracks in the manifold. There could be a small crack under the heat shield that i cannot see but i could not hear the usual tick of an exhaust leak.

So, I check the ground on the BHR kit, it's good. I check the firing order of the wires, they are installed right (figured as much since it idles fine when warmed up). So, I decide to pull the rear L2 plug and this is what I see:

The plug was wet, didn't smell like fuel and didn't smell like coolant. But what else could it be?

http://www.flickr.com/photos/9krpmrx8/5897685186/http://www.flickr.com/photos/9krpmrx8/5897118091/http://www.flickr.com/photos/9krpmrx8/5897117953/

Here is a video, you can hear the rough idle and it smooth out.


BHR pipe, not sure what the rattle was since with the pipe off there is no rattle or signs of resonator failure.

9krpmrx8

iTrader: (46)

My next step is to test the ignition with a timing light. After that I guess it's compression test time but once this is a cold start problem, not a hot start problem and now it takes longer to start when cold but when it's hot it starts no problem.

TeamRX8

iTrader: (25)

What plugs are those?

hoss -05

iTrader: (4)

WOW Scott that plug is messed up! It looks as it has maybe has not been firing? How dose T2 look?

Man we really should have gone in on the compression tester. You and I both know of the quality of our local mazda remans. Keep me updated.

9krpmrx8

iTrader: (46)

Hmmmmmm, just pulled it again RE6C NGK IR, just looked at some old ones pulled from another 8 and they are RE7C.

I'm gonna pull T2 now.


Edit. Looks like the RE6C plug was introduced in 2006 to combat hot start problems.

TeamRX8

iTrader: (25)

Those are the hot leading plugs recommended for cold climate operation. You are doing canyon runs with those and triple digit ambient temps ....

If the wet plug is not fuel then it has to be from the cooling system.

dannobre

iTrader: (3)

That can't be firing properly....might want to check the coil

...swap the leading for trailing connectors and see if it idles better......

I wouldn't run the 6 range plugs down thee in the summer,,,they were to help the cold climate guys from fouling in around town driving

The Yukon coils are way better than stock.....but I have seen them fail

bse50

You also changed your wires not long ago right? Check if you didn't break the terminal!

wcs

iTrader: (2)

Those plugs look like they are mostly wet on the threads .....
Just throwing this out there ....

Is there any chance your Oil Filter is leaking and the oil is running down in to the spark plug holes (or Oil pressure sender or Oil temp, sandwhich adapter leaking)?

Just idea's

olddragger

iTrader: (3)

no smoke in exhaust? No kind?

1st thought: possible seal gone bad.
But no additional oil use--no smoke?
2nd thought :water seal--but no smoke and no coolant lost?
3nd :Then--maybe front o2 sensor?

RotaryMachineRx

iTrader: (1)

Might as well start with the cheapest/easiest thing to check

kma5783

iTrader: (7)

Good Point, What do your AFR's look like while all this is going on? Running Rich?

9krpmrx8

iTrader: (46)

Thanks guys.

AFR's and STFT, LTFT, etc. look good (as far as I can tell) except when this is happening. The engine load is about 50 or so though and usually it is only at about 25 at idle. The load does drop to normal as the idle smooths out.

There is no oil leakage of any kind and no coolant loss. Every once in a while at initial start up there is a tad bit of white smoke for a second but that has always been the case for as long as I have had a midpipe (since engine was put in).

I did replace the BHR wires recently and also rechecked the firing order and checked to make sure the wires were secure today and everything was good. I will test the coils in the AM with a timing light and report my findings.

olddragger

iTrader: (3)

If you have white smoke in the summertime--that maybe a small coolant leak on cold start?
The leak may seal itself after the engine warms due to metal expansion?
In the summertime you shouldnt have any condensation smoke on start up---winter temps-- yep maybe?
But a coolant leak that small shouldnt make the engine run like what yours is doing ?
Smart to check the coils/ignition, but I dont understand why it changes after the engine warms up?

Did you say your vacuum is only 15/16? Is that cold or hot--does it change?

Glad (in a way) I am not the only one with gremlins!