EvoOtto

iTrader: (2)

This condition happens very infrequently but I would love to know if anyone has experienced this before and if I should be concerned with it. The car idles fine and then all of a sudden the A/F ratios drop to 16-17 to 1 and the car stumbles quite a bit. Tapping the gas in most cases will fix the problem but this does concern me. The car drives fine and if I put it in drive and use the car as normal when this happens there are no issues. Any thoughts?

richardjh

I had this when the PCV hose at rear had come (been left) off.

There is a hose between the intake pipe (between air cleaner and turbocharger) to the crankcase (top right, rear, near oill filler cap).

Make sure that is not your problem. And check all other hoses while you're in there...

Rich

03chi-town0Z

iTrader: (7)

Any recent changes to the car?

neogeo64

iTrader: (3)

The idea of hoses coming off scares the hell out of me as this is my first car with a turbo.
Should everyone buy different type of clamps and replace the stock one's even if they have an all stock setup?

Slyy

iTrader: (2)

seems weird. My a/f cruises around 14-16 at idle and sometimes it went to 17; but no studder.

What is our a/f suppose to be at idle? i thought 14-17 was okay?

i know at WOT we're suppose to be at 10.5-11.5

baggelis

my afr at idle is the same as when cruising 14-15.5 if you re hitting 16s and 17s you may have an exhaust leak.

Slyy

iTrader: (2)

Yea, i have the same. While at idle and cruising im' at 14-15.5

Just seen it hit 17 at odd times; but only once.

EvoOtto

iTrader: (2)

I had installed an I/C about 2+ months ago but this issue happened much later on. Boost is still running up around 22.8-23 psi. Hoses all looked good. No signs of issues under the hood.

Currently I have TP, 2.6, Evo X BOV, muffler mod, and I/C

dubkeith

The stumble at idle could easily be the a/c cycling on and off. 16-17:1 a/f at idle on a stock ecu doesn't sound abnormal when hot.

Veronica

iTrader: (2)

Have you checked the fuel flow regulator (IIRC?) vacuum line (under the intake box (search for pix)).

Because if the hose comes off it leans mixture and a vacuum leak would cause an idle stumble.

zebra4

Did you ever figure this out? My car does the exact same thing... A/F raises to around 16.5-17, rpms drop and it idles rough until it richens up again.... All of my hoses are connected i have checked and double checked.

EvoOtto

iTrader: (2)

I haven't figured it out yet. It doesn't do it much anymore. I have a new condition now. It may or may not be related. My boost is fluctuating throughout the rpm range. I swapped out the DV and that did not fix it. Next thing I'm going to do this weekend is check for leaks. Fingers crossed. I have had so little time it makes it hard to do anything to my car so I just drive it without getting into boost. I need to get my baby fixed!!! I'll post my findings.

TOralliart

iTrader: (8)

I see this happen to me once in awhile also. Tap on the gas pedal fixes it but its just weird.

03chi-town0Z

iTrader: (7)

Well, it's time for me to join the club. Just started happening the other day. Only difference with me is that when I come to a stop, afr goes rich (11-12) and is VERY slow to correct back to stoich. Sometimes overcompensates to 16-17 and takes awhile to stabilize. Two or three times, though, instead of leaning, it goes rich further (9-10) and the rpms dip and car stumbles HARD. Stalled out on me once...

Only happens at idle and/or when coming to a stop. Vacuum is consistant ~20in hg on the boost gauge throughout the whole process.

Fuel trims are exactly where they should be during cruise (stoich) and at wot (mid-11ish)

Will update upon further diagnosis.

sstevojr

iTrader: (7)

I managed to get this resolved on my car. The big things to do are:
1) Increase your idle to 900rpm (906 is what I use in EcuFlash)
2) Set your timing to 14* in the idle region
3) Make sure you have NO MIVEC in the idle region (+10IN/0EX)
4) Possibly rescale you MAF/MAP depending on mods. IIRC you have a pretty sweet CBRD intake, so I'd reckon you should rescale