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http://www.youtube.com/watch?v=HBXZv...er_profilepage

Hey everyone,

I've had my Evo VIII for a little over a year now and I started getting this weird idle about a few months ago... ok here is the story

One day i fell asleep listening to music with the key ignition on the "on" possition. The car wasn't running and the battery died. I jumped the car with jumper cables and I pulled a "crank sensor code." I didn't think to much of it because the car was running fine. I cleared that code and I have not seen it since. About a month down the road the car was running PERFECT! UNTIL!!!! I pulled a "CEL code" I figured it was just my tune so I got a retune and the car still had the problem. The tuner didn't edit my map so the the CEL wouldn't come one, but i still dont think the CEL code was my idle problem. My friend suggested putting a high flow 3' cat and a spacer for the rear o2. So i installed them! I cleared the CEL code and I still haven't seen it. The cars idle was nice and smooth for about 2 months with no problem. After this weekend the CRAPPY idle came back. Now I REALLLLYYY don't know what the problem is because I have no check engine light (no OBD2 codes).

I tried the good ol' "reset the ecu" trick. (When you disconnect the battery for a few minutes and put it back on) WELLLLL.... IT WORKED! I was so excited to see that that was all it was!

But wait, its not that easy.... THE ROUGH IDLE CAME BACK TO HAUNT ME AGAIN!!! I'm getting very aggravated and I wanted to see if anyone else has ever had this problem!

Also one more thing. As you can see in the video the idle at around 900RPM, but sometimes it feel like idling at 400-450RPM after a nice drive on the highway. And sometimes it idles a 1050ish RPM.

Please, any feedback is well appreciated! I just want to know what my next step should be!

MOD LIST: Evo 9 turbo and diverter valve, light crank pully, 3 1/2'' FMIC, LICP, 3" TBE, 255 pump, halman boost controller.

 

your idle sounds fine to me. sounds like you have cams done to it.. you sure you dont have bigger cams?

 

Sounds like you have some cams in the car. It sounds normal to me.

 

LOL! I know it sounds like I have bigger cams, but I don't. This idle is not normal for a car that has stock cams. Its smooth when its running correct.

STILL LOOKING FOR CORRECT ANSWER!

Thanks for the feed back jnebs and evoracingstar!!!

 

*edit* didnt see your other post... Are you sure the previous owner didnt put cams in? Thats still my guess. GL figuring it out

 

im having a idle problem to my car sounds just like yours and i do not have bigger cams. does it do it when your car is cold?

 

could it be misfiring? you check the spark plugs?

 

I just saw your post too dac001.

No, its cold idle is smooth and can be 1500RPM or 1900RPM, whatever my car feels like doing LOL!

Its got a mind of its own, that's for sure.

 

It has spark on all 4!

 

Stock cams and a cam lope means your idling lean.

Find out why and fix problem solved.

Could be a vacuum leak, faulty o2, plenty of crap.

 

Check your crank sensor ohms.

 

what are the afr's at idle?

 

Vacuum leak. Check all your hoses for a leak. Or it could be intake manifold gasket.

 

Check the EGR vac hose. That thing tends be a common issue.

The effects though are not always the same with each car. My idle was rough and that was the problem.

 

car sounds great, stop bragging