Legacy199 Posted December 6, 2017 Share Posted December 6, 2017 Has anyone experienced long cranks and seemingly misfires upon cold start? When my Legacy sits for more than five hours and the temperature is below 35 degrees Fahrenheit or so it has a significant amount of trouble starting. I will go to start the vehicle and it will crank for a good six seconds and try to turn over, either not completely starting and stalling out or it will start with a seemingly misfire and the engine will bog a good bit. After the start the car runs normally with no issues or codes. The battery strength seems strong (original battery) and cranks well, but it feels like something is not catching. My 2007 Subaru had the exact same problem in cold weather even after a new battery. Note* the car starts completely normal in temps above 40 degrees. If anyone has had similar issues or has any idea what may be going on I would greatly appreciate feedback. Thank you. Link to comment Share on other sites More sharing options...
ehsnils Posted December 6, 2017 Share Posted December 6, 2017 Seems to me that it's running lean and not compensating correctly for the lower temperature. Either an intake leak like bad PCV, gasket or bad hose or that the engine temperature sensor is bad and has to be replaced. Link to comment Share on other sites More sharing options...
dgoodhue Posted December 6, 2017 Share Posted December 6, 2017 How many miles are on your car? Link to comment Share on other sites More sharing options...
capttris Posted December 6, 2017 Share Posted December 6, 2017 are you allowing 3-5 seconds for the fuel pump to pressurize (with the key in the last position before cranking over), before attempting a start? Link to comment Share on other sites More sharing options...
FLlegacy Posted December 6, 2017 Share Posted December 6, 2017 I would try: 1. Battery load test 2. Clean maf and throttle body 3. Check temp in ecm against actual temp 4. Fuel pressure Link to comment Share on other sites More sharing options...
FLlegacy Posted December 6, 2017 Share Posted December 6, 2017 Also, have the plugs been changed? Mileage? Link to comment Share on other sites More sharing options...
Legacy199 Posted December 6, 2017 Author Share Posted December 6, 2017 There are 54,000 miles on the vehicle. I do allow over three seconds for the car to prime. Thanks for all the feedback so far. Link to comment Share on other sites More sharing options...
YeuEmMaiMai Posted December 7, 2017 Share Posted December 7, 2017 I have seen very intermittent long cranks (like 3x since I have had my car)Â what is your fuel pressure after the car sits for a while? if it is bleeding off it could be the cause of long cranks... Link to comment Share on other sites More sharing options...
5thGenCVT Posted December 9, 2017 Share Posted December 9, 2017 I've been having the same problem with my 2014 legacy, which is why I joined this forum. I replaced the battery thinking that it was that but even after replacing the battery I still had the same issue. So I did some research online and I found that some possible causes are a dirty MAF sensor, or simply that the engine isn't getting enough air so it leans out. I did have a very dirty air filter so I replaced it and it seemed to work better, but it's still taking 5-6 seconds to turn over, it's not misfiring anymore like it was before, where it would idle very badly and stall. I'm going to try cleaning the MAF next. Link to comment Share on other sites More sharing options...
ehsnils Posted December 10, 2017 Share Posted December 10, 2017 After changing filter and cleaning MAF it can be a good idea to disconnect the battery for an ECU reset and let it re-learn. It will take a few drives before it has re-learned fully, but that's normal. If the problem persists it can still be either an air leak in the intake like bad PCV or a bad O2 sensor. Link to comment Share on other sites More sharing options...
5thGenCVT Posted December 10, 2017 Share Posted December 10, 2017 I will also try that, but when cleaning the throttle body and the MAF sensor do you have to disconnect the battery too? I heard that if you don't do this you risk damaging the MAF sensor when you plug it back in. Link to comment Share on other sites More sharing options...
Legacy199 Posted December 11, 2017 Author Share Posted December 11, 2017 Thanks a lot for the input 5thGen. A little added note for the starting issue. It seems whenever the temperature is consistently cold (below freezing) the car will have much less trouble starting. It's almost as if now the car learned it is cold out and it has adjusted for a proper start. When the weather is warm and goes back to below freezing it will have the issue starting as stated. This is the exact issue my 2007 had and now that I'm in the first winter with my 14 I'm seeing it again. Deja vu Link to comment Share on other sites More sharing options...
ehsnils Posted December 11, 2017 Share Posted December 11, 2017 I will also try that, but when cleaning the throttle body and the MAF sensor do you have to disconnect the battery too? I heard that if you don't do this you risk damaging the MAF sensor when you plug it back in. The throttle body is sensitive, but the MAF is not a big deal as long as you have the ignition off when you disconnect it and reconnect it. Link to comment Share on other sites More sharing options...
5thGenCVT Posted December 13, 2017 Share Posted December 13, 2017 The throttle body is sensitive, but the MAF is not a big deal as long as you have the ignition off when you disconnect it and reconnect it. Why is the throttle body sensitive? Is there a special process to clean it? Link to comment Share on other sites More sharing options...
ehsnils Posted December 13, 2017 Share Posted December 13, 2017 Why is the throttle body sensitive? Is there a special process to clean it? The throttle itself in the throttle body is mechanically sensitive so it shouldn't be forced open/closed because it can damage the mechanical parts controlling it. Link to comment Share on other sites More sharing options...
5thGenCVT Posted December 25, 2017 Share Posted December 25, 2017 Just a quick update, cleaning the MAF sensor didn't fix the problem for me. Link to comment Share on other sites More sharing options...
ehsnils Posted December 25, 2017 Share Posted December 25, 2017 Check/clean the PCV valve too, it shall rattle when you shake it. Link to comment Share on other sites More sharing options...
5thGenCVT Posted December 25, 2017 Share Posted December 25, 2017 Okay I will try it Link to comment Share on other sites More sharing options...
02LGTSNJ Posted December 28, 2017 Share Posted December 28, 2017 I was having a similar issue just last week. Eventually it threw a code and it was my Crankshaft position sensor. It a PITA to get swap out bc it is in a tight area, but it can be done without removing anything. Mine was directly underneath the alternator behind the belt. I was lazy and didn't feel like changing it out so for about two weeks every time it acted up I had to pop the hood and reach in and jiggle the wire and it would fire right up. I finally replaced it the other day and no trouble since. Link to comment Share on other sites More sharing options...
Legacy199 Posted December 29, 2017 Author Share Posted December 29, 2017 Interesting about the crankshaft, 02LG. My legacy acts just fine for the most part as long as the temperature is consistent. It's starting pretty well here in PA considering the low temps of 4 degrees Fahrenheit. The only thing to take note of is that my car acts very goofy in the seriously cold temperatures, like the radio display having a laggy delay and the USB not working immediately. Throwing gears with the manual transmission is definitely tighter, but I actually like the way it feels compared to warmer (looser) temperatures. Link to comment Share on other sites More sharing options...
YeuEmMaiMai Posted December 29, 2017 Share Posted December 29, 2017 the radio display on the radio is a LCD and yes they are laggy when cold. you should see it when it dips in the -20s outside. also the oil in the transmission is thicker and harder to move the gears around. Link to comment Share on other sites More sharing options...
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