Is it EGR valve? intermittent rough idle

[fkmp5]

My 03.5 Protege5 mostly sits in my garage. It has 58,500 miles on it. About a month ago, I was driving home from some errands and at a stop light it had a very rough idle and at times felt like it was going to stall (but doesn't). When the light changes and I give it gas, it feels fine. At the next light, it goes back to it's erratic idle. I topped off the gas, put in fuel injector cleaner and reset the PCM. After it sat for a few days, I drove it around the neighborhood and it seemed fine. Another week or so goes by and I drove it again to a restaurant. It was driving and idling fine until I was about halfway there, then at the next stoplight the erratic idle was back. It never stalled, but felt like it was going to. I made it to the restaurant and ate, when I left to come home I started the car and it had the rough idle right from the start. It was that way for most of my trip home, however, when I hit a few red lights towards the end of my trip home it was back to idling normal. It has always driven fine (even when the rough idle is there), it never seems to buck or do anything odd when I'm giving it some gas.

Last year, boostdprotegelx (Damian) worked on it to remove the vtcs after I sucked in one of the screws. It has run fine since that work was done on it up until this crazy idle started a month ago. Spark plugs were also changed last year.

Please help with suggestions. Might it be the EGR valve? or if that went bad would it not be intermittent and always idle rough?

 

[P-Funk!]

Yep - first place i would look at is the EGR.
Try cleaning it first.
Spray brake cleaner through a staw into the throttle body opeing (square hole at 6 o'clock position visible when throttle plate is open). Let it set for a few minutes. Start the car.

If it doesn't work - replace the valve.

 

[fkmp5]

thanks! will give it a try. I did see a how-to on the egr valve on the forums.

 

[fkmp5]

okay, i used throttle body/carb cleaner and cleaned out the throttle body tonight and also took off the egr valve and cleaned it out, although it really didn't seem that gunked up. I think maybe Damian might have cleaned it last spring when he was working on the vtcs thing. I put it all back together and reset the PCM again then let it idle in my garage for about 15 minutes and of course it was running fine-- haven't driven it yet, but the weather is crap today, so i'm not going to take it out for fear of getting stuck somewhere in the rain. i'm going out of town this weekend, but when i get back i'll try to take it out for a spin and see what happens.

 

[Brian_K]

it could also be the IAC valve on your throttlebody

 

[Fresco]

or it could be none of the above, if you have a stock intake, check the accordion looking part of the intake i mean really look through it and check for cracks

 

[fkmp5]

Fresco: I have the injen intake, thank you for the suggestion. Brian: thanks for the idea, I'll check the IAC valve next and try to clean it up a bit.

 

[fkmp5]

Okay, I went out to clean it and I noticed there is a piece broken off of the IAC Valve.

Here is a pic of one I found online compared to mine. You can see where I drew the yellow arrow there is a piece missing, which looks like it would have a hose attached to it. What would the other end of that hose be attached to?





(btw on the pic of my IAC the black nub above it is missing a rubber hose-- I know, I slid it off to get a better picture-- it's not really missing).

 

[Fresco]

question you mentioned you had your vtcs removed, by any chance was the sensor removed as well?

 

[fkmp5]

I believe so, boostdprotegelx did it for me.

 

[Fresco]

whats broken off is the inlet for the antifreeze that runs through the throttle body

 

[fkmp5]

do you think that would cause problems or is it just supposed to warm the throttle body somehow

 

[Fresco]

do you think that would cause problems or is it just supposed to warm the throttle body somehow

its supposed to keep the throttle plate from sticking in cold weather, i bypassed mine and use that line for my coolant temp sender, take a quick look at the passneger side of your intake manifold, there should be 2 sensors that look exactly the same right above the mani

 

[fkmp5]

yeah, they are there and the electrical connectors are attached, but there are no hoses attached to them.

 

[Fresco]

hmmm im gonna say that may be your problem, it could also be a bad sensor, i assume you have no cel, maybe run a scanner and see if you have any codes that wont cause a cel, i had the same problem i replaced both of those sensors and never had a problem ever again, i believe the stored code was a p0660 or something like that something about manifold pressure bla h blah dont quiet remember the full details

 

[fkmp5]

thanks. you are correct, i have no CEL. i'll see if i can get it scanned, of course I unhooked the battery and reset everything, so I'll wait and make sure it does it again first. do you think i should have hoses hooked up to them or just replace them and leave them attached to nothing if I have the stored code? thanks again for your help and input.

 

[Fresco]

thanks. you are correct, i have no CEL. i'll see if i can get it scanned, of course I unhooked the battery and reset everything, so I'll wait and make sure it does it again first. do you think i should have hoses hooked up to them or just replace them and leave them attached to nothing if I have the stored code? thanks again for your help and input.

let me go take a quick pic of mine because i believe they are linked to the intake mani....brb

 

[bigpturgeon]

Just adding my 2 cents, have you replaced your coil packs recently? Because i have had the problem you speak of and replaced coil packs and all was well.

 

[fkmp5]

No, I have not done the coil packs.. thanks for the suggestion

 

[bigpturgeon]

I had the same problem one second it was fine the next it was bad changed my spark plugs, packs and wires and problem solved.