Rough Idle???

[deejayspinz]

Ok, having a prob while idling. The SOB seems like it wants to stall. If you have every popped your intake and suffocated the airway, this is what its like. When the car is warm, and the idle drops to ~500 (normal), then the car wants to stall as the idle drops to near ~250, it goes back up to 750, then back and forth. It hasn't stalled, but gotten close to it. I checked the intake and there are no blocks (BTW - the intake is still stock). Been thru 2 tanks of gas and no change. Nothing on the car has changed except the oil (myself). The only diff is I used a FRAM oil filter instead of the stock Mazda one... I can't see how this could be the prob though. Unless of course, the filter is cloggged... Naaaaa.... I am due into the dealer on Wed, but wanted to know if anyone else has had this...
Add this to a warped brake rotor, and I am starting to feel like I am in lemon territory here... Mazda - make a beleiver outta me!

[Silvermp5]

This is a shot in the dark but maybe on of your spark plug is gone bad.

Check those.

[YP5 Toronto]

The same exact things happens with me...been like this for the past month. My car is a year old though....so I'm not sure. Plus I have an intake.....and exhaust, so we both don't have an exact model of how this issue came to be. Let us know what you find out.

[ALS-protege]

Not sure if this is related or not...But here goes anyways...

I too was having an idle problem with mine where it would feel like the car was gonna stall...
I brought it back to the dalership to check it out...What they did was just adjusted the idle to rev a tad higher...
Seems to be ok now...except when the AC kicks in or sometimes when it rains...

[markque]

Where do you fill up your tank? How low do you let it go before refueling? Are you aware that some gas is dirty or at least full of sulphur? Sometimes there is sediment in the bottom of the tank but usually not with newer vehicles.
Some people are really fussy about not letting their tank get below half - best to avoid sucking dirt into the injectors.
My car is over a year old. I also had a K&N filter before the AEM. I'm also using a non-Mazda oil filter. None of the changes affected idle.
This story is a long shot: many years ago, a former coworker went to school in Toronto. His older car was like new when he left town but it didn't even last a year. He discovered the "discount" gas station he was using had "watered-down gas", which ruined his car. Now I don't believe water and gas particularly mix well but I haven't had a gas and water cocktail lately. Nonetheless, he somehow discovered that station was using inferior gas, as others were also affected, so it's a possibility. (I'm sure it's no longer in business.)
Good luck - hopefully Mazda can help out on Wed.
BTW, one warped rotor and an idle problem doesn't constitute a lemon. Officially, a lemon is designated when the dealership cannot repair the same recurring problem after three attempts. So unless this is your fourth rotor, you got a LONG way to go before entering Lemonville! And I have a hard time believing any Jap car, let alone Mazda, would produce a lemon. We're not talking Chrylser, Ford, or GM here...

Mark http://msg.toprotege.com/iB_html/non-cgi/emoticons/smile.gif

[firefly]

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote </td></tr><tr><td id="QUOTE">And I have a hard time believing any Jap car, let alone Mazda, would produce a lemon.[/QUOTE]<span id='postcolor'>

Not exactly...the Civic I had before the P5 is a lemon. The possibility of getting a lemon is less for Japanese car but they're out there.

Your idle/stalling problem sound very similar to the Civic I had...except that mine actually stalled out. Everything was stock on that car and I've tried different gas...still no help. Dealer replaced MAF sensor, idle control valve, ECU, throttle position sensor but that didn't fix it. As far as I know even Honda doesn't know why their engine stalls out at random (a lot of ppl on the Civic board have the same problem).

[KDawgONE]

I had a similar problem on my gen2 Pro. It seemed to get worse as it approached oil change time. It alos stalled out sometimes when I &quot;glided&quot; in neutral. Mazda of Canada has no idea why this happens but my dealer installed this Mitsubishi PVC filter thing and it helped. M of C told them to take it off cause itll get worse but once removed, my idleing problem came back so it is once again on again and running fine. It shouldnt have any bearing at all, but, once I installed my breather filter on my valve cover, that seem to help. I also recently had my ECU replaced but, the idle stopped before it was replaced. Ed B. (minRX7) also had a similar problem and suggested replacing the coolant sensor. This should've had no bearing whatsoever, but, it made the biggest difference for both he and myself...

[deejayspinz]

I also have a 99 Protege, and for a bit it did the same thing. Turns out that Mazda had (and still may have) a recall on the ignition coil for that model yr. I am going in tomolow as my engine light just came on this eve. Anyone know engine light codes? Does the P5 have a flashing green light diag on the ECU? My Prelude did.

[firefly]

O...I forgot to mention that when you gas up, don't try to put more in when the pump stops. Do that and see what happens after a couple fillups.

[hondakilla]

Your idle should be at 600-700 rpms as per your manual so if its lower then that its not running right.

I've had O2 sensors make my idle rough in the past...have you used race fuel? Too much octane booster? Both can burn out our O2 sensors but if you haven't then it seems to early for them to burn out.

[deejayspinz]

Rough Idle - Update. Took the car into dealer today. It was the EGR valve. Supposedly was clogged or jammed.... Works fine now... They did not replace it, only cleaned it. We'll see how long it lasts until next time....

Dave

[ChopstickHero]

i sound so newbie, but what's an EGR valve?

[Gen1GT]

Exhaust Gas Recirculation Valve

[ChopstickHero]

ahhh... i see. thought that thing was called PCV? Positive Crankcase Ventilation valve?

[Gen1GT]

two different things...