TheLoyale Posted November 10, 2011 Share Posted November 10, 2011 What would cause extremely low idle at cold start up? IAC? Cause I'm talking "Low idle" 300rpm then slowly works it way up to 700rpm (It should idle at least 1500rpm when cold) I have no codes, and it runs fine other wise. I have cleaned the IAC the best I could without taking it off the intake, I have also ran Seafoam through the intake system twice before this started. All Vac lines are new (Even the 3/4" ones) All electrical plugs are clean. Everything is up to par maintenance wise. Ideas? Link to comment Share on other sites More sharing options...
Fairtax4me Posted November 10, 2011 Share Posted November 10, 2011 Could be a bad temp sensor. Engine thinks it's warm, so it doesn't idle up. Otherwise, the IAC is sticking. Link to comment Share on other sites More sharing options...
TheLoyale Posted November 10, 2011 Author Share Posted November 10, 2011 Could be a bad temp sensor. Engine thinks it's warm, so it doesn't idle up. Otherwise, the IAC is sticking. Good thought. Didn't mention this, but, after you drive it some place, shut it off and come back 10-20min later and fire it up, it'll kick up to 1600rpm for a sec then lower down to normal running speed (Which is normal, why it doesn't do that when its cold is beyond me) Link to comment Share on other sites More sharing options...
heartless Posted November 10, 2011 Share Posted November 10, 2011 If it isnt the IAC, it would more than likely be the temp sensor... I am having a slightly different problem with my beast - once it is warm, tranny in park, it "hunts" for correct idle - almost stalls, then up to about 1000, then almost stalls again... As long as it is in gear, it is fine - like at a traffic light - idle is spot on at 700rpm. put it in park - starts surging up and down... I am pretty sure it is the IAC on mine - first cold start it kind of takes a moment or 2 to get up to proper cold idle... Where did i put that can of Seafoam, anyway? Link to comment Share on other sites More sharing options...
MilesFox Posted November 10, 2011 Share Posted November 10, 2011 every now and then my 94 legacy will idle high enough to drag on the brake at stops, or the idle may fluctuate, and return to normal. Sometimes when i start the car, it stumbles and hesitates, revs up, and then comes back to normal. I probably have a sticky IAC. It would be a good idea to change the engine temp sensor if you have not already, as this may help with the delayed shift points, and the fuel economy with the open exhaust you have. Link to comment Share on other sites More sharing options...
Olnick Posted November 10, 2011 Share Posted November 10, 2011 I would encourage you folks to actually remove the IACV from the car and give it a thorough cleaning--did mine 6 years ago and it's been idling perfectly ever since! And it's so satisfying to see the dirt and gunk flow out of it as you spray and turn the cylinder!!! Also clean out the air line feeding the IACV and replace the PCV. Happy wrenching. Link to comment Share on other sites More sharing options...
TheLoyale Posted November 10, 2011 Author Share Posted November 10, 2011 Fuel economy is not an issue anymore, turns out the MAF was sh*t. Now I'm getting over 24mpg. It would be a good idea to change the engine temp sensor if you have not already, as this may help with the delayed shift points, and the fuel economy with the open exhaust you have. Link to comment Share on other sites More sharing options...
TheLoyale Posted November 10, 2011 Author Share Posted November 10, 2011 I am leaning towards IAC as I replaced the CTS 2 years ago. The CTS is on the Coolant Crossover, correct? Link to comment Share on other sites More sharing options...
Fairtax4me Posted November 10, 2011 Share Posted November 10, 2011 Yes both temp sensors are on the crossover pipe. The one for the ECU (controls mixture) is the large one with the 2 pin harness plug. When you replaced it did you use a new part or used? If new, was it Subaru OEM? I think an IAC gasket costs $3 or $4 from the dealer and it only takes 15 minutes or so to remove it and spray it out. I recommend Intake and Throttle Body cleaner. Cuts that cruddy grimey stuff like a hot knife through butter. BTW I got the grille today Tom. It looks great. Thanks alot man! Link to comment Share on other sites More sharing options...
TheLoyale Posted November 10, 2011 Author Share Posted November 10, 2011 Theres two on the crossover? I guess so (One for the gauge and one for the ECU) but I've never seen the other one. But yes, I replaced the 2 pin sensor, not with a Genuine part though, I got a new one from Carquest. I am thinking of taking the IAC off this weekend and clean it thoroughly. Probably won't get a gasket since the dealer will have to special order it. Red RTV or Ultra Gray will do just fine. Happy to here you got the grill. Link to comment Share on other sites More sharing options...
Fairtax4me Posted November 11, 2011 Share Posted November 11, 2011 Special order? Seems like any dealer should carry that one in stock. Not like it really matters though. The gasket makes it easy, but RTV should work as long as you don't use too much and get it in the mechanism. Link to comment Share on other sites More sharing options...
TheLoyale Posted November 11, 2011 Author Share Posted November 11, 2011 Special order? Seems like any dealer should carry that one in stock. Not like it really matters though. The gasket makes it easy, but RTV should work as long as you don't use too much and get it in the mechanism. Maybe it depends on the dealer, Wilde Subaru which is the closest dealer, doesn't carry much for seal/gasket sets in stock (Totally BS!) But they have oil filters! Anyway, While at operating temp and in Drive. It idles at the the first thin line right above the thick line (0rpm) So I am guessing thats like 300rpm? Its smooth and quiet and has always run about that low (Can the IAC also be causing this?) Link to comment Share on other sites More sharing options...
Fairtax4me Posted November 11, 2011 Share Posted November 11, 2011 I think the first line is about 500 rpm. That is a little low. Could be IAC related, the top is adjustable and moving it will change idle speed a bit. (I think) You can also adjust the throttle stop screw to bring up idle a hair, but you need to adjust the TPS after doing that. You're not supposed to mess with the throttle screw, but that doesn't stop people who don't know what they're doing. Anyone in the past 15? years that engine has been in existence could have messed with it. The factory marks the screw and lock nut with paint. You can check it to see if it has ever been adjusted. Speaking of throttle body. I noticed the one off my wagon was stuck closed when I had the intake off during all the engine fiasco. So I pried it open and looked inside and it was full of gunk and crud, and the edge of the throttle butterfly was all coated in the same crud, making it stick when closed. Cleaned it up with intake system cleaner and it doesn't stick anymore. Link to comment Share on other sites More sharing options...
TheLoyale Posted November 11, 2011 Author Share Posted November 11, 2011 During cold start up, it will idle right at the 2nd line and slowly rise to the middle line. During Running temp in drive, it also idles at the 2nd line lol. I don't get it. I know what you mean about the build up of crap on the butterfly, took care of all that when I bought it. I have adjusted the IAC to bring the RPM up, but then it goes right back to where it always is (Guessing the ECU is compensating?) So I put it back, and same goes for the TPS. Gonna check out the IAC saturday and also replace both vac lines that run off it. Link to comment Share on other sites More sharing options...
Fairtax4me Posted November 11, 2011 Share Posted November 11, 2011 Right well the first line is 500, second line there (the thin one) is 750. Normal idle is supposed to be around 650 - 700 IIRC. Mine idles at about 550 - 600 in drive when warm, just barely above the first line. Link to comment Share on other sites More sharing options...
bheinen74 Posted November 11, 2011 Share Posted November 11, 2011 bad alternator. Link to comment Share on other sites More sharing options...
TheLoyale Posted November 11, 2011 Author Share Posted November 11, 2011 bad alternator. Please elaborate. This Alt has 222,000 on it, so I wouldn't be surprised. Link to comment Share on other sites More sharing options...
heartless Posted November 11, 2011 Share Posted November 11, 2011 I think an IAC gasket costs $3 or $4 from the dealer and it only takes 15 minutes or so to remove it and spray it out. I recommend Intake and Throttle Body cleaner. Cuts that cruddy grimey stuff like a hot knife through butter. just curious - what material is the gasket made of? is it the cardboard type, or cork, or what? I have gasket material (both the cardboard type and cork) so I could feasible make a new gasket. . . also have ultra grey from when we pulled my motor for the reseal job this past summer (thank you again, Tom) also - Tom - you said you got a new temp sensor from CarQuest - do you remember about how much it cost? thinking mine might be the original one yet... Link to comment Share on other sites More sharing options...
heartless Posted November 11, 2011 Share Posted November 11, 2011 bad alternator. I am also curious about this statement - replaced my alt last year... Link to comment Share on other sites More sharing options...
TheLoyale Posted November 12, 2011 Author Share Posted November 12, 2011 Fixed. Link to comment Share on other sites More sharing options...
Fairtax4me Posted November 12, 2011 Share Posted November 12, 2011 What fixed it? just curious - what material is the gasket made of? is it the cardboard type, or cork, or what? I have gasket material (both the cardboard type and cork) so I could feasible make a new gasket. . . It's paper with some kind of metal in the middle. Link to comment Share on other sites More sharing options...
jarl Posted November 12, 2011 Share Posted November 12, 2011 Fixed. How??? Link to comment Share on other sites More sharing options...
heartless Posted November 12, 2011 Share Posted November 12, 2011 Fixed. yay! but you know better than to leave everyone hanging - spill the beans - what fixed it for you??? Link to comment Share on other sites More sharing options...
neednotherwagon Posted November 30, 2011 Share Posted November 30, 2011 also interested in fix please Link to comment Share on other sites More sharing options...
bork Posted December 1, 2011 Share Posted December 1, 2011 Was this a set up? Dont make me hunt you down on the way to Rhinelander! Link to comment Share on other sites More sharing options...
Recommended Posts
Please sign in to comment
You will be able to leave a comment after signing in
Sign In Now