Mach929

iTrader: (3)

I took my injectors and fuel rail off and replaced a suspect seal and fuel rail spacer, still having same problem. It will idle fine for maybe 30 seconds after driving, then drop and will have a loping idle, also is somewhat noticeable at steady low rpm cruising say like around ~3000 rpm. At idle when it does this vacuum will rise to about -14-15 as opposed to -19-20 inch hg. Fueling seems to be fine but why won't my a/f gauge sweep at idle any more?(yes it's warmed up), maybe i should look into spark issues. Anyone have any other ideas. I'll also be doing a compression test tomorrow after work just to rule out internal problems.

bripab007

I don't see how it could possibly be internal problems if the car idles fine for 30 seconds then has the problem. Sounds more like a bad AFM or a vacuum leak.

brgracer

iTrader: (14)

I'd put in new plug wires just to take such a simple fix out of the way. Might want to just throw in your old injectors and rail, just to see if it goes away as well.

Mach929

iTrader: (3)

yeah i don't think i have internal issues but i have a compression gauge kit, doesn't hurt to check. Yeah i'll be doing plug and wire change too. and if i have to i'll swap in the old injectors(damn i hate doing these injectors, the car is too low and i have a bad back)

bripab007

My money's on vacuum leak or AFM. In fact, mine did a very similar thing back when I was running the stock crossover and the alternator chewed a hole in the resonator box.

Mach929

iTrader: (3)

well my vacuum gauge read normal until after sitting for 30 seconds. Also holds boost just fine. afm is possible too

magnamx-5

iTrader: (7)

AIC probably needs to be tuned check your shop manual it isnt hard to do but if it isn't set up right your idle will suck. If it iss blocked off like mine then idle can only occur once the o2 sensor gets lit. also if your afm isnt getting the full vacuum it could swing shut and cut fuel you could prop the door open abit to eliminate this as a culprit.

olderguy

iTrader: (19)

Stock AFM? Mine got that bad without even the emanage hooked up when I finally found the wiper wasn't making good contact.

bripab007

Yes, that's very similar to what mine did with the vacuum leak. Actually, I'd say it was more like 10-15 seconds of ok idle, then it would go to lopey, almost dying idle.

Mach929

iTrader: (3)

where was your leak i've tested all the connections i messed with my mityvac. All hold just fine. How is it that the vacuum leak doesn't occur until after a sitting for a few seconds?

bripab007

Well, I actually had two leaks, but neither of them would be your problem. One was a new hole in the resonator box and the other was a threaded hole in the compressor housing for the wastegate arm bracket bolts (moved the bracked and didn 't realize that the hole was drilled and tapped all the way through the housing).

Anyhow, my point was that I, too, was surprised that a vacuum leak would cause the car to only have a rough idle/problem after several seconds of "okay" running. Must have something to do with the car dropping into idle mode...perhaps it just becomes more evident when the ISC valve tries to create a steady idle and causes it to go haywire...I don't know.

steelrat

Mine does something similar. Cold start, fine.... then it will idle OK at a light for a while... then it will get a crap idle, and have the vac gauge reading go to crap.

There was a suggestion on m.net about adjusting the idle screw while having it jumpered with ten and grnd. I just haven't had the time to try it yet.

However, I seem to remember the last time I was doing something with ten and ground it was idling like complete crap. <G>

Will have to investigate further. If I get a chance... hopefully some time over the week-end I'll re-adjust the idle and see if it helps.

Oh and just so everybody knows... it was happening pre-new motor in spring, and also it was happening before the EM and 305's too... so I've just been living with it. <G> I think it just got worse with the 305's.

Remember though, with the SC my car is "supposed" to have idle dip... Just didn't think it would be that bad. <G>

Dave,

Mach929

iTrader: (3)

i already tried adjusting the idle, did nothing. My car was not doing this before in i swapped in my 305cc injectors. They were sent out to be cleaned and tested prior to installation, results came back great on all injectors. Using all new o-rings, insulators and grommets. Emanage setup with correction factor to idle 305cc injectors. I'm really confused about this one

bripab007

Okay, so it's gotta be something to do with the R&R of the injectors, right?

jayc72

iTrader: (14)

Change your correction back to 205/205 or 205/230. See if that helps. If not you might have torn or pinched an o-ring installing your injectors and that could be where your vacuum leak is coming from.

My money is on the correction, mine did something very similar.

Jay

Mach929

iTrader: (3)

i guess that's quick and easy to try, i don't know why i wouldn't want to use the emanage to correct for larger injectors

Mach929

iTrader: (3)

ok just did compression test. 203,195,194,198. A little higher than factory 192, but i don't think this is causing my problem. this is getting annoying

bripab007

So, reinstall your old injectors?

kung fu jesus

iTrader: (1)

bad AFM and/or O2 sensor.

Mach929

iTrader: (3)

emanage.

with the injector correction set to 205/305(how i had it set) the car idled like crap

with the correction set 305/205, even worse.

with the correction set back to stock 205/205 the car idles percfect with my 305cc injectors running a bit rich during cruise but smooth.

I wanted to play around with the settings some more like 205/230 and 205/270 to see the limit where i can keep good idle and lower cruise richness but i ******* broke my damn emanage cable somehow.

One question, i adjusted the screw closest to the green led on my autotune by accident, how i do set that one where it's supposed to be?

Another side note i got my boost controller in and cranked it up to 10psi, clutch slips like mad as soon as i hit 4000 rpm.