Tanispyre Posted May 23, 2007 Share Posted May 23, 2007 I have a 1991 Subaru Legacy with a 2.2L Turbo engine and a 5-speed manual transmission. I am having a problem with the cold idle speed. When I start the car with the engine cold, it idles rough (at about 1200 - 1500 rpm), it also seems to produce no power as even the slightest engaging of the clutch causes it to stall, until I rev the engine. After I rev up the engine the idle speed rises to between 3000 and 4000 RPMs and stays there, Once the engine temperature starts to rise the RPMs start dropping, when the engine is fully warmed up, it idles at about 600 rpm. The check engine light is not on. I have taken it to a couple of mechanics they check the computer to see if it gives any errors but it does not, at this point they say they don't know what the problem is and can't fix it. The problem first appeared after I had the clutch replaced in the car. I have taken it back to them several times to try and fix it but they have been unable. I had some other work done at a subaru dealership and asked them about it, but they were not able to find anything wrong either. Do you have any suggestions on things to check to try and identify the source of the problem? Quote Link to comment Share on other sites More sharing options...
lrschum Posted May 23, 2007 Share Posted May 23, 2007 Mine does a similar thing, but only at about 2000 for the first few minutes of driving. Then it settles down to about 500-600. The colder it is outside, the longer it will stay at a high idle. I've asked a few people about it and it seems like the general consensus is it is nothing serious, especially since the problem (at least on mine) follows the same pattern and has never gotten worse. I don't have the drop in power you're experiencing, but it does make timing the shifts a little more difficult b/c the car returns to idle slowly and stays high until I have made about 10 shifts or so. Of course, this is a different engine than yours, so this might not mean much a whole lot for your problem. Quote Link to comment Share on other sites More sharing options...
porcupine73 Posted May 23, 2007 Share Posted May 23, 2007 Could be a couple things, but here's one from EndWrench: Legacy Idle Quality Complaints If you encounter a complaint of idle quality, especially during warm-up, check to see whether there is corrosion between the spark plug terminal tips and the spark plug wire’s contact. Quote Link to comment Share on other sites More sharing options...
Tanispyre Posted May 23, 2007 Author Share Posted May 23, 2007 Mine does a similar thing, but only at about 2000 for the first few minutes of driving. Then it settles down to about 500-600. The colder it is outside, the longer it will stay at a high idle. I've asked a few people about it and it seems like the general consensus is it is nothing serious, especially since the problem (at least on mine) follows the same pattern and has never gotten worse. I don't have the drop in power you're experiencing, but it does make timing the shifts a little more difficult b/c the car returns to idle slowly and stays high until I have made about 10 shifts or so. Of course, this is a different engine than yours, so this might not mean much a whole lot for your problem. This is very different from the normal cold engine idle speed. 2000 rpm is about right for the cold idle speed. When I start my car and start driving it, the car idles at almost double what it should normally idle at for a cold idle. The fact that the rpm changes as the car warms up is not a problem, that just means that the thermostat is working and adjusting the throttle like it is supposed to. This extremely high idle speed makes shifting when the engine is cold very difficult, and puts a lot of extra wear on the engine components, as I can smell hot rubber when I get stopped for a while at a stop light Quote Link to comment Share on other sites More sharing options...
Tanispyre Posted May 23, 2007 Author Share Posted May 23, 2007 Could be a couple things, but here's one from EndWrench: Legacy Idle Quality Complaints If you encounter a complaint of idle quality, especially during warm-up, check to see whether there is corrosion between the spark plug terminal tips and the spark plug wire’s contact. Interesting idea, I have pulled the spark pugs to look for build up as a sign that it is running to rich, but my multimeter had dead batteries so I did not check the cables. I will look into that and get back to you. Quote Link to comment Share on other sites More sharing options...
porcupine73 Posted May 23, 2007 Share Posted May 23, 2007 I think they're saying to look for erosion at the spark plug's connection to the spark plug wire. Also I've heard of it happening between the coil connection to the spark plug wire on two cylinders (depends on which way the electrons flow I guess in this waste spark system). Quote Link to comment Share on other sites More sharing options...
Tanispyre Posted June 1, 2007 Author Share Posted June 1, 2007 Replaced the spark plug cables and spark plugs, the #4 cylinder cable had some cooked on coolent so i though that might have been the problem as the above suggestions have lead. While the warm engine idle is smoother, the cold engine idle is still extremely high. So I think I can rule out the spark plugs and cables Quote Link to comment Share on other sites More sharing options...
Skip Posted June 1, 2007 Share Posted June 1, 2007 two items come to mind the CTS (Coolant Temp Sensor) This is for the ECU not the dash indicator. When one went south on one of my Leg T-wagons it did not light the CEL. The reading was there but the output from the CTS was weak - the ECU reacted in a similar manner (mine is an 4EAT though) These are around thirty (30) USD at any good parts house. The other is the IAC (Idle Control Valve) there may be some "gunk" built up and until it is warm (gunk turns to a less viscous material), it has problems regulating the air. Cleaning it may solve your problem - do not try to adjust it trust me on this one. Posts on both of these items can be found. Hope this helps. By chance do the cooling fans run at odd times? Quote Link to comment Share on other sites More sharing options...
Tanispyre Posted June 5, 2007 Author Share Posted June 5, 2007 two items come to mind the CTS (Coolant Temp Sensor) This is for the ECU not the dash indicator. When one went south on one of my Leg T-wagons it did not light the CEL. The reading was there but the output from the CTS was weak - the ECU reacted in a similar manner (mine is an 4EAT though) These are around thirty (30) USD at any good parts house. The other is the IAC (Idle Control Valve) there may be some "gunk" built up and until it is warm (gunk turns to a less viscous material), it has problems regulating the air. Cleaning it may solve your problem - do not try to adjust it trust me on this one. Posts on both of these items can be found. Hope this helps. By chance do the cooling fans run at odd times? I am liking this Idle control value being gummed up idea. The problem started right after having the engine pulled to replace the clutch. The first time I took it back to the mechanics who did the clutch, both the warm and cold idle were off, they said that they cleaned out the throttle area, which did seem to fix the warm idle problem. Any suggestions on where to read about the IAC? I will start by googleing it. I will update with my results. Quote Link to comment Share on other sites More sharing options...
OB99W Posted June 5, 2007 Share Posted June 5, 2007 [...]Any suggestions on where to read about the IAC?[...]You could start here: http://endwrench.com/images/pdfs/Fuel.pdf Quote Link to comment Share on other sites More sharing options...
Olnick Posted June 5, 2007 Share Posted June 5, 2007 Any suggestions on where to read about the IAC? You can search right here on USMB too. Type in Idle Air Control IACV. Good luck. Quote Link to comment Share on other sites More sharing options...
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