Hey guys,



The problem is this, when I first left Trifecta and went HPT and loaded my stock tune, it sounded like my car was gonna die, it would rev up then settle and almost stall, then rev up again and this would repeat itself until it warmed up. Then it would drive fine.

After I progressed in tuning this issue was no longer an issue, but now I have this slight rumble when I idle as my AFRs fluctuate from 13.5 to about 15.3 regularly but staying around 14.3-14.8 primarily. As it leaves 14 my car will increase in pitch or decrease in pitch coming out the exhaust. So think MMMMmmmmmMMMMmmmmmMMMmmmmmMMMmmmm or RooaaarrrRoooaarrrrRoooaaarrr etc. Varying every second or so.

Also when I drive I'll let go of the throttle and be in neutral, sometimes my car will settle at 1500 RPMs until I come to a complete stop. This also happens sometimes when I am at a stop completely it'll just out of no where start climbing RPMs until about 1500 and just sit there for a second or so.

I went out and bought a new Evap Purge Solenoid and installed it, thinking it was the problem, but the problem is still there.

Could it be my MAF sensors or MAP Sensors? Perhaps my Evap Vent Solenoid? A Vac leak? (Keep in mind Colorado never gets to -20 in vac)

I've had my oil catch can for quite some time now and there's no signs of oil on the level fill indicator. Could this be the problem?

I performed a boost leak check and I don't have any leaks.

My car drives fine, WOT feels great, I do get a little black smoke when I go WOT though, I'm sure this is normal though. I still achieve all 25lbs of boost when I do go WOT.

Thanks for the help

http://www.youtube.com/watch?v=x3uAR...66AUAAAAAAAAAA

 

How we supposed to hear the car with the loud music?

 

I know, when I got home last night, I didn't even think about it, I just started recording. I was so focused on what I was doing I didn't even really notice the music lol.

I don't know if my phone (SGS2 from Tmobile) will pick up the exhaust rumble or not. I'll try and take a video of my boost gauge going from about 18 to 16 then back to 18 in vacuum

 

Post some pics of how you have the catch can installed and what line was used.

 

Do a boost leak test. Small boost leaks will do that to your idle.

 

x2 on small leaks. i got tuned with boost leaks, fixed em and my afr does that sometimes. needs retune (mine does)

 

He said he did a boost leak test.

 

ah didnt catch that.

whens the last time you cleaned your MAF? seafoamed your car?

 

Boost leak checks won't catch the leaking BPV unless it's done pre-turbo. Check the o-ring on the Forge cap. Someone else had that issue.

 

I didn't actually do it myself, I don't have the tools, but I had it done and they said it's holding 24 psi. He said he didn't wanna keep doing it because all he's doing is adding air in my crank case.

So theres a chance he didn't do a good job.







Here's my catch can



Okay doing this right now.


Never cleaned my MAF before. And I haven't used seafoam, just had Jiffy Lube do their fuel injector cleaner a couple times.

 

nevermind the funky AF's...whats that song called???? haha jk but seriously..who?

and my car is doing the same thing. another thing might be a change from winter gas to summer gas...fuel trims might be alittle off. i tried unplugging my evap sensor and it didnt help....so sub'd

 

Here is the thing.. There can be 1000000000 Things causeing this, heat soak first off can cause this, second thing is a bad sensor, or somthing close to it ( dirty maps, dirty 02, etc) The only times i see the rpm fluctuation issue at idle was with those statements above.. Frogstofall had a similiar issue but his was actually on my side and his ( a corrupt file) Yes it happens. But ill elaborate a little bit more..


A 02 sensor reads the carbon atoms and ect and verifys the afr by the carbon and oxygen in the air flowing. Simply put, there is more to it,, just easier put lol.. So if there is a slight leak (exaust or after maf) it can cause many issues. A bad 02 sensor can cause hesitational issues, along with speratic afrs, and wot lean... Map sensors can do the same thing... What you need to do is (send me a log with this speratic idle) if possible, because the log you sent to me last the trims skewed to +10% in a split second and went fine after that .. As if the purge opened up and dropped fuel in.. or some other way. It doesnt happen all the time (which leads me to a sensor issue) I just cleaned my maf and my idle is 10 times better.


Ure coast idle is fine, your commanded actual idle is fine, (its doing what the ecm is telling it to)..

 

i might send you a log sometime this week of my idle James...cuz mine is doing pretty much exactly what you explained...weird afrs, and wot lean. and its a brand new sensor...my second one. so i must have a leak somewhere or a different bad sensor

 

What's a lean Afr? I'm asking because I'm commanding 12.2-12.3 wot

 

in the 15's...but it bounces around

but i think i just have a bad sensor somewhere because it kinda hangs around there regardless. but it bounces around like the OP's

 

Yeah there' is no way its 15s unless a bad sensor. before you buy anything send me a log. Frossb and also you mike

 

Here ya go...

ren & stimpy "its log" song/commercial - YouTube