Idle problem getting worse!! Helllp!!!
 

Well, My problem with idle continues to worsen. Basically the car runs fine until sitting at idle for more than about 15 seconds, seeming telepathically linked, stuttering as soon as I wonder if it will:confused:, then getting progressively worse at high temps, and very bad when at idle with the AC running. Needless to say, it's been over 100 degrees regularly here in Sac lately, and anyone in the car can feel it, especially under AC load, including a friend riding in the car for the first time last week, turning to me and saying "that doesn't feel right??!!".
At first it seemed that if I slipped it into "N" it would stop, but now it's basically doing it all the time. When it's happening, in "N" I can bring the revs up, but it feels like it's stumbling, as if it's got a vacuum leak. Puzzling to say the least.
Cooling fans run normally, coming up immediately with AC activation, and as previously stated, the car runs great otherwise.

Reviewing symptoms in the FSM, the Bypass Air Control Valve sounds like a possibility. Anyone with any experience with this problem? Looks like I would have to remove the "collector" or "upper intake manifold" to expose and clean the connector contacts and clean and/or replace this valve. Opinions and suggestions please!!

Glenn

As a first step, you might want to just clean out the interior of the throttle body with some carb cleaner. This often fixes poor idle problems. I think there's a "How-To" for this in the "How-To" locker.

You may also consider these possibilities:

1) Check the plastic duct from the MAF Sensor to the intake. Examine for cracks, etc. Also, the plastic housing to the T/B.

2) Check all hoses connecting to the plastic bits of the air intake.

3) Check the boots on all the coil packs -- sometimes a worn or cracked boot will cause an idling problem.

I suggest these, because, from the description, the problems could be temp related. As the car warms up, something expands. Also, make sure the T/B et al are securely bolted down. One member had a similar problem which was caused, simply because the manifold was not securely bolted down.

Just some thoughts.

Thank you Gentlemen. I'll take a close look at your suggested areas. My mech already mentioned checking all the manifold bolts, and I've done that. Cleaned the TB back in Feb, but worth another look. Priced the BACV at $190, at Dave's price :eek: , so think I'll try eliminating simple stuff like air leaks first!! If that doesn't turn anything up I can pull the collector and take a close look at the valve and connections b4 considering replacement. Thanks again!

Glenn

You don't have to remove the collector to clean the IACV. Just the Throttle body, The valve is underneath it.

Harvey.;)

Thanks Mate!!
 

Thanks Harvey. I was going to take a closer look at the diagram before trying that, but you've most likely saved me some extra time and frustration. :)
Just discussing it with my Subie mech while picking up the wife's Legacy, and he thinks it's most likely electrical. Coil ? If it would only do it with some regularity it'd be a bit easier to nail down.

Glenn

Re: Thanks Mate!!
 

That's why I suggested it might be a spark plug boot. If a coil were going bad, I'd think the problem would be more consistent. If the rubber on the boot were cracked, after a warm-up, it would expand and allow the spark to jump. Trouble is, I don't think you can get the boot on its own (though, in a thread somewhere, someone had found some spark plug wires with boots that would work if you use the ones from the distributor side). Or, perhaps some of our suby mechs from a dealership could find a hidden part number (like for the window clip) for the boots.

Good point Randy. I just replaced one coil/wire with one from his parts car. Think I'm gonna try to get this "thing" happening as regularly as I can while sitting in the garage, running the AC, etc and try to pin it down to one cylinder by pulling one injector plug at a time. Once I know if it's one cylinder or a more general problem, like vacuum leak or dirty/failing BACV a more detailed search can proceed. Thanks for all the input gents! It's much appreciated.

Glenn

Randy aka Aredubjay Wins the Prize!
 

Finally, with the "stutter" happening fairly regularly, my Subie Guy diagnosed the problem as 2 coil-boots failing. Apparently, with the AC running, at idle there was enough load on the motor to cause it to worsen, and he could hear them snapping from under the car when running. After replacing one of questionable age/condition previously I just bit the bullet and replaced the set. Let me say the driver's side was a beotch, even with the battery out!!! The coils weren't so bad, but the connectors were a bear to reach, and release, with room for only one hand and needing 2!!

She runs like a new car!!! Purrs along like a big happy feline, and I'm one happy camper, minus $502, of course. Now I can do my Stage1 install, and start saving for some Koni's!:cool:

Glenn

My mech. said it was the coils and wanted me to replace them all ($1400). I was able to hear a "snapping" sound as well. But I'm happy for right now because getting the car back from the dealer they left my fog lights on and my car completely died. When I got it jumped, the problem went away. I guess the computer reset and it runs better for now.

So if you don't have the money right now, try disconnecting the battery.