2000 rpm on cold engine ?

[Megell]

Hi everyone. I'm hoping you can help me with an idle problem that has been increasingly getting worse. First thing in the morning starting the car, it revs immediatly to 2000 rpm and a few moments later down to 1700/1800. A tap on the throttle pedals sometimes brings it down to around 1500.

After driving and warmed up it still seem rather slow returning to idle after stopping at lights etc; Sometimes the idle seems to stick up around 1500 for no reason and takes several moments to come down. Sometimes it doesn't come down until I pop the hood to check it out and when I get out to check the engine, It always comes back down to 700 rpm before I get the hood open.

I don't like this high rev in the morning on a cold engine, especially when it's zero outside in the winter.

Car is 91 ej22t, w/5speed. 179999 miles as of this morning. Car runs perfectly otherwise. New plugs, clutch and service recently. 29.5 mpg on last fillup.

Is this a possible IAC valve? If so what can I do personally to help. Have tools, but not much experience with Subarus.

Any help much appreciated.

Mike

[Megell]

Thanks Nipper, I started having this high Idle issue the last part of this winter, but the first start in the morning was only around 1400 rpm or so. This is the first of July and it's reving up to 2000. It never used to do that. Most of my experience with FI cars has been a slighter high rev initially after starting and then idle down as it warms. I'm seeing a definate increase in early AM starting revs and am concerned about going into the next winter if this continues to increase in rpm on first start.

I've had this car going on four years and it never did it before the last 6 to 8 months. Also, after its warmed up it still is starting to idle well above 1000 rpm and not wanting to come down to the normal 700 rpm range. Sometimes, it just seems to go to 1500 to 1700 all of a sudden for no apparent reason. I can sit there for a while and it will eventually come back down to normal idle, even when warm, like today in 90 degree temps.

There's something wrong and it's getting worse. IAC valve??

Mike

 

 

Well define cold.

 

Secondly thats normal if its zero, an engine has to warm up too. Every engine on the planet does that, the question is how long does it do it for. It should drop down to normal as the temp gauge starts to move up.

 

 

nipper

[four-fleet-feet]

I'd give Nipper's list a go, but here's a couple suggestions. You mentioned new plugs. What kind did you use when you did it, or did you have someone else do them for you? I'd check what was actually put in. If you can do it, I'd actually pull one plug to see what it looks like. If it's normal, that's good. If not, that might clue you in to a problem.

 

If you don't do your own work, when did you have your air filter done? If not lately, change it and see if it helps. Matter of fact, even if you did have a shop look at it, I'd still get into it and pull it all the way out. It might look clean from the top, but turn it over and take a look. I've had shops tell me I didn't need a filter after a top-peek check when mine was so crudded up it was disgusting (when I'd already planned on changing it - myself!), and one time they actually forgot to put it back in during an oil change!

 

(Jiffy Lube, and they paid dearly for what that mistake cost my truck's engine on its 1500 mile sojourn three days later - now I always double check any work done on any vehicle I take in for service anywhere. My poor truck had all sorts of problems from that day on. I can't watch, you don't work. Yeah, I have a few mechanic-trust issues...)

 

I only mention the air filter because you said the problem goes away when you go to raise the hood - more air?

 

Also, if you had any kind of service under the hood which required anyone to disconnect lines for anything, double-check them. Loose vacuum lines and other things of that ilk can cause all sorts of problems. If you've had any flickering on-off CEL, get it read even if it isn't still on. Maybe you have some chewed-up wiring due to last winter's cold Colorado critters!

 

A check of the PCV filter wouldn't hurt, even though it probably has nothing to do with this. Many people forget all about them. They're cheap. Get a dealer one.

 

Good luck; there seems to be a spate of rough/high idling going around the board.

[Bmm001]

there seems to be a spate of rough/high idling going around the board.

 

My independent shop thinks a lot of idle and stumbling/missing problems and even CEL's are due to poor quality gas.

 

Many of us here drive Subies from the 1990s--that was before the era of 10% ethanol across the board (don't think it was standard in PA before a year or two ago, for example).

 

Is it possible that these engines just don't run as well in general with the current gasoline formulations?

 

My mom and dad often fill their cars up at one particular chain of gas stations, and have intermittent check engine lights and stumbling issues. I never fill up there, and have had far less of these troubles. Coincidence? Maybe, maybe not.

 

Brian M.

[Megell]

do a tune up, and clean the ldle air control motor

 

 

Plugs, gearbox(s) oil change, air filter, clutch, rear seal all done at the Subaru dealership in Durango CO. about 8000 miles ago. The engine oil and filter I did myself as I wanted Mobil 1 full sythethic since it is turbo'd.

I never thought about a new air filter. I'll replace that and see if it helps.

When the engine revs, it is absolutely smooth. It just revs and occaisionally does not want to come back down to idle. A couple of times it actually idleed at 1800 after a warm restart and never did come back down. I had to shut it off and restart and then it was fine for awhile.

Nipper, where is the IAC Motor and how do you clean it, remove it? Take it apart? Air pressure it off?

Thanks,

Mike

[ccrinc]

I suggest you also check out the coolant temperature sensor. (Located in an obscenely hard to reach spot on the coolant crossover pipe under the intake manifold.) May just be corroded.

 

Emily

http://www.ccrengines.com

[Suzam]

+1 on the coolant temp sensor I had a 95 Legacy 2.2 that did something very similar.

 

And Emily is right! It is hard to reach!!!

[Megell]

I suggest you also check out the coolant temperature sensor. (Located in an obscenely hard to reach spot on the coolant crossover pipe under the intake manifold.) May just be corroded.

 

Emily

http://www.ccrengines.com

 

 

Thanks everyone for these suggestions. I didn't think of the coolant sensor. I'll give that a try. Any special tools required to get to it or is it just a matter of having enough beer on hand?

Mike

[frag]

Thanks everyone for these suggestions. I didn't think of the coolant sensor. I'll give that a try. Any special tools required to get to it or is it just a matter of having enough beer on hand?

Mike

 

Remove the hose going to the pcv and push some pigtails aside. A medium lengt extension with the proper size socket will get it out. I think I used long nosed pliers to remove the connector first. There will be a small amount of coolant seeping out. You can lower the coolant level in the rad by a couple of inches to prevent that.