I'm working on fixing this really rough idle. I've had to do it slowly due to a serious lack
of funds.. I've gotten this old 3.1 to run somewhat better, but the idle is all over the place.

I've replaced: Plugs, wires, new o2 sensor, fuel system clean out. I've had the coil packs checked, and it's ok. I'm also currently running 93 oct gas w/ jet fuel (STP )
in the tank now.

She is running better, and the milage is back up. But when I stop at a light, the idle
gets pretty rough. It seems to start the rough idle when it is warm. I still haven't got
complete power back, though when she does get up to speed, she runs pretty well.

Could it be a sensor? Map? TB? Exhaust maybe? The one thing that I havr noticed
is that it it doesn't throw the check engine light on like it used to. It just happens
once in a while. Before, when I would speed up or slow down in traffic, it would throw
the CE light one.

I noticed my exhaust is hanging down a bit too.(Clamp must be going) I don;t think that
that would be the cause, but hopefully explain as much as possible will give you guys
an idea what it going on. Any ideas would help... <br>

my wagon's idle has been a bit erratic, though doesn't seem to be "all over the place" like yours. the initial issue was a leak between the upper and lower intake manifolds.
there was also a vacuum leak before the HVAC controls were connected, as well as the vacuum sphere thingy.
now that those items have been dealt with, it mostly just does a little hunt 'n' seek below 1k rpm.
the current guess is something to do with the IAC.

just one more thing for you to check, i guess, but it's all i've got for ya' at present...

<br>


Have you seen the turbo wagon?

14.069 @ 98.91mph

I think im experiencing the same prob. Mine idles so rough that the door panels squeak when idling.

For me, I think it is my timing is off. <br>

There is an "idle learn" procedure that should be done on the stock v6. It allows the ecm to figure out where the IAC should be at during normal driving. It's supposed to be done with a scantool, but I think I have a set of notes for the procedure without the scantool. I remember it was a PITA, but without it the idle was never right.

-->Slow

Idle Learn? Would I have to re-set the ECM to do that? I'll have to look into that. This
poor wagon has a bit over 130k, so at this point it could be anything. Though I find it interesting that many others have the same problem that I do.

My idle was really, really bad (like there was a pinball machine in there or something)
but with the 02 sensor, it helped a good bit.

Wierd part is the idle goes nuts when it warms up. that's what made me think that
it could have been a exhuast issue.... <br>

There are a few methods floating around, but this is the o­ne used by GM techs.

1. Reset ECM by pulling ECM fuse (underhood) for a few seconds.

2. With A/C turned off, start car and immediately put it in Drive
with your foot on the brake. If the car does not start initially,
keep trying WITHOUT putting your foot on the accelerator.

3. Let the car idle in gear for at least 5 and no more than 7 minutes.

4. Shut off the car for 10 seconds.

5. Start engine, place in drive and let idle for 5 minutes.

6. Shut off engine.

Idle is learned.

You could also look into a new IAC valve, could be a faulty EGR, how old is the catylitic converter? That could be plugged.. check under the car and see if it shows any sign of overheating.. ie glowing red hah

Thanks Hybird, I think I might try that..

As far as the cat, it is as old as the cav itself... ...


<br>

I had something similar happen to my car took it down to my friends shop ran it through the computer and it was my map sensor that was gone. <br>


"Sometimes ya just gotta go...."

Dave-

I sounds like you have the same problems, I am having with my 2.2L. I have replaced most of the parts that you have. I am going to get my coil packs and ICM checked tonight. I will let you know what I find out. I might also check into the MAP sensor didn't think of that.

I replaced my MAP sensor, the IAT sensor and my car still had a crappy idle.
Now it won't even start. It cranks but just won't start.
It also has a very weak spark...that's the coil pack right?

Dm of mD


<img src = http://home.earthlink.net/~mgdm13/_images/JKrew-MD.JPG>

89Sunbird wrote:I think im experiencing the same prob. Mine idles so rough that the door panels squeak when idling.

For me, I think it is my timing is off.

MINE does the same thing... and I not only think the timing is off, I'm pretty confident it is. but it's not too far off, maybe barely a notch at most, just enough to make it idle funny. but it's not a horrible idle like you describe, tho I do get all the same stuff. seems to be a common problem with our cars. But as for me, I can fully say I've had several timing issues in the past. I've had the timing re-set at least 3 times since I've owned the car.



Originality and Creativity surpasses Popularity

Unplug the EGR connector.

Spray around the intake with TB cleaner...see if the idles change



1991 3.1L V6 Sunbird LE
15.365@88.52
Full Interior...3-Speed Automatic.

Satisfied Customer of:
POWERSHOP PORTING SERVICE

my sisters beretta done the same thing and it was the torque converter lockout selenoid, when its idling good unplug it and it will run good, but if you unplug it with it ldling rough it will stay idling rough. went to a transmission shop and they told us to just unplug it cause it was so hard to change. and it has run great every since.

try out some fuel additives and see what that does....just my 2 cents.





Speed costs money, how fast do you want to go?