I know this has been discussed a ton and I've searched. I am having idle issues that is becoming unbearable to me. It's almost embarrassing when stopped in public.

The car idles fine until it gets up to operating temperature and then begans to act up. The RPMs begin the bounce and the exhaust begins to pop. At some point it seems that it will stall out, however hasn't done that yet. I can temporarily fix this by messing with the A/C.






The car is protuned and was doing it before and after the tune. The spark plugs have been recently changed with OEM plugs. I've swapped the blue relays and the issue persists.

im at a loss

 

Could be a range of things, but I'd start looking at the below list.

1. Vacuum leak
2. Injector issue causing lean scenario (do you have a wideband?)
3. Throttle body issue (take your lower intercooler pipe off of the throttle body and see if anything looks wonky)
4. Dirty MAF sensor
5. Restriction in the exhaust. (Are you running a cat?)
6. Dirty fuel sock
7. Dirty/Clogged PCV valve

Take a look at those items and report back.

 

i have cleaned the MAF sensor and the issue persists and the exhaust is free flowing (no cat or res).

I don't have a wideband. The injectors in the car are FIC 900 I believe. I don't have any kind of CEL though.

The tuner wasnt able to find the issue when I had it tuned this past august.

i will check the other stuff you mentioned and report back. Thanks for the advice!

 

Today I checked and cleaned the egr valve, looked at the throttle body and checked all the hoses for leak and it all appeared fine.

 

Sounds like a misfire to be.
Id start off by pulling the spark plugs for inspection. You can add pictures if your unsure on what to look for.

Another possibilty would be unmetered air i.e boost leak or vaccum leak.

Have it scanned for codes also. There may be some pending codes that will help point you in a better direction.

 

the spark plugs were changed less than 2k miles ago with OEM plugs and was doing the same thing with the old plugs. It's not throwing any codes.

how do I check for boost leak or vaccum leak?

 

Need to buy a boost leak tester or make one from home depot parts.

Pretty much you pressureize the turbo system through the turbo compressor and listen for air leaks or spray soapy water.

Also if plugs were replaced already id do a compression test. To me it sounds like a misfire in the videos

 

This what the gauges look like in Torque and there is one code pending, although I don't know if it's related to this issue.

 

My friend had a similar issue, turned out to be a stretched timing chain which is a fairly common issue.

 

I'm still gambling on a vacuum leak somewhere. I'd definitely look into getting a wideband if you can. If one of the injectors was getting stuck or something you wouldn't know.

 

yeah but it doesn't do it until the engine is warmed up.
That's my guess too. I plan on getting a wideband once I fix this issue. I'm probably going to take it to a shop after the holidays.

 

Any update on this? I've noticed my car will be sitting fine at a stoplight then sort of stumble, but not bad enough to cause popping or anything too unusual.. just kinda as if i've turned on the AC and the car stumbles for a second. Seems weird.

 

Also, I see yours looks to be ziptied, but for the search functions sake if someone looks at this thread in hopes of resolving their own issue: https://www.evolutionm.net/forums/ev...s-do-asap.html

 

unfortunatly no. I'll probably have to wait until after the holidays and take it to a shop.

 

Have you recently messed with your break booster? I had the exact same issue after I changed out my cmc. The problem was the o ring inside the break booster was tangled which caused a vacuum leak for me.