Hey all,

Hoping you can save me from the dealership!

My idle starts normal, then slowly drops when the car is idleing (like at a stop light)

It usually ends up at 585 - 600 rpm when sitting, and has stalled out a couple time when I braked for a light.

I've cleaned the air filter/ the MAF/ the throttle body.

Air Intake side of throttle body was pretty clean but intake manifold side was pretty dirty. I also noticed oil on the gaskets and there was a lot of carbon build up in the maifold opening. (does this mean anything?)

fuel system was cleaned recently (at minit lube) and I always run premium gas.
Spark plugs just changed to NGK iridiums - all plug holes were spottless except one has very little amount of oil blow back.

I tried to find any vaccuum leaks...but everything looks tight? I do hear a hissing (more like a small steel ball rolling around constantly) comming from the passenger side front (where the first spark plug is)

Any thoughts??

Thanks!

 

Did this problem start up after your visit to the minit lube? Or after you cleaned the throttle body?


Sounds like you may need to do the Throttle Valve Closed Postiton Learning and Idle Air Volume Learning procedures if you bumped the butterfly plate in the TB. I believe you can find the directions for these at www.motordyneengineering.com.

 

This has been going on for a while...
First i was getting a "misfire" code and the was having the engine sputter, so i changed the spark plugs... it helped a bit but didn't solve anything.

I've done the idle air relearns and TB sensor positions a dozen times now too with no luck...

 

I'm at a loss then. I was going to blame the minit lube but it sounds like this was happening well before taking it to them. You haven't thrown any codes from this issue? Might be time to bite the bullet and head to the dealer.

 

sounds like a vacuum leak.

 

Ya, i think will have to take it in...maybe next pay cheque
I'm gonna go with vacuum leak too.

 

Bingo

Best thing to test a vacuum leak is get a can of brake parts cleaner..

and spray the vacuum hoses (slightly) and if the engine rev's up on its own you have a leak in that particular area.

 

+1 vacuum leak.

 

**Weird Finding** (or not)
When the A/C is on the engine idles a bit higher so everything is okay, but as soon as you turn it off it acts up again.

Even with the a/c on the car still idles a bit weird... i feel a lot of vibration from the engine.

 

Either a shot motor mount, low idle, or vacuum leak.

 

Have you found the problem?

 

It sounds kind of like my issue. Low idle and i always felt like i had more power weirdly when the a.c was on of all times until i was running in the higher rpms. Hmmm.

 

not yet. I'm going to tinker a bit (use some brake cleaner to check for vacuum leaks), but realistically i'll be getting it to a shop soon. It just seems you have to do all the diagnosing yourself so shops don't pull the wool over your eyes.

 

Hey All,
Just an update. The mechanic ran all sorts of diagnostics on the car and came up with this..
My intake temperature is too high. Apparently my injen intake filter sits right where the radiator is (when I have in in the short ram set up). The intake air temperature that is being drawn in is actually hotter that the ambient air.
Hopefully the wording is right on this : The MAF reads the volume of air comming in, but it is less dense because it is hot. The ecu leans out the A/F mixture to compensate causing the engine to sputter / sometimes cut out/stall.

I have just switched back to CAI, and all looks good so far. I am just worried about water getting into the intake system.

 

^^ sounds like BS to me. the ECU is designed/programmed to compensate for IAT, and if it's not doing it correctly you've got other issues...

I see IAT's through the roof with my twin turbos (during long periods of idle). Even with my JWT intake which was basically sucking air out of an oven (err heat shield LOL)

I never had a single issue like this, at all...