So the other weekend I installed a new AMS TBE and now my idle appears to sound extremely rough... Exactly as shown in the video below:

http://www.youtube.com/watch?v=IgzkhjzlOk4

This video accurately depicts the long "lope", not sure if thats the right term, that I'm hearing at idle... Yes I know this is a X and I have an VIII but the sound at idle is identical.

Is this normal?

I've scoured other EvoM threads on issues with rough idle and found a few items to check:

Checked IC piping connections
Checked vac hose connections
Checked to ensure no exhaust leaks
Checked and replaced plugs gapped 0.023
Cleaned MAF
Out of ideas...

Two items not checked from the other threads is compression and boost leaks.

My current setup consists of the following:
AMS TBE w/ test pipe and O2 fix, K&N Filter w/stock MAF, Walbro Fuel Pump, 80k miles on the clock

My car has not been tuned.

Thanks in advance for any input.

SOLUTION:
Timing belt was mistensioned when installed causing the belt on the intake cam to slip two teeth. Belt reinstalled and tensioned correctly. Car idles like a change and I no longer get alot of engine movement at idle.

 

Bump for the morning crew...

 

boost leak test

 

+1 on the boost leak test. did one on mine. i had the same issue. turn out had a rock in my brand new ams intercooler. ahhhhhh!

 

Dumb question, but like a rock went through it?

 

exhaust leak- ex mani/ turbo, 02, downpipe?

 

did you check the egr hose under the throttle body area?

 

I've been thinking about this all week. How would a boost leak affect my idle? At that low of RPM I would think it would be a non-issue.


Don't think it's an exhaust leak cause when I get under the car while its running I don't hear any leaks and I can't see any soot on any of the joints but Ill double check.

I saw this mentioned many times. Ill try to crawl under the car with a flashlight and see what I can find.

 

I'm having the exact same issue with my IX. The idle sounds identical to that. Everything seems fine while I'm driving but when I come to a stop it idles like that almost to the point of stalling sometimes. Every now and then it idles just fine but that is happening less and less. There has been no check engine light or any other warning lights come on. I tried changing the plugs but got the same thing. Any ideas as to what it may be will be greatly appreciated.

Well now that I posted this now I just got a SES light on

 

There is your problem.

l8r)

 

Working on getting some tuning time with our local tuner. Ill post if it fixes the problem.

As for the other items I've found no boost leaks or any type of exhaust leak.

 

There's some conspiracy going on or something. I have the exact same problem. Is there any ideas out there? I've checked everything as well. I got rough idle plus backfiring

 

Those are normal symptoms for a car without a tune. Get the car tuned.

 

Did you get tuned after installing the exhaust?

 

I have a rough idle and i have been tuned. When i come to a stop it drops to like 400 and then bounces back to normal?! any idea?