LeolaPA Posted January 4, 2012 Share Posted January 4, 2012 Hello, I am just new here, but have been reading the posts through Google searches, and have benefited from that already! We have a 95 Subaru Legacy LSI with the 2.2 motor. My daughter complained about stalling problems, so I started working on it during her Christmas vacation. I drove the car some, and it was stalling at stop signs. I replaced the crankshaft sensor. That seemed to fix that problem. BUT, she said it was stalling when cold, and wouldn't run until the idle dropped to about 800. That was true. It would start, but would stall if you put it in drive or reverse. In the mean time, the car quit on me on one of my trips to buy parts, and it would only run with the MAF sensor unplugged. So, I got a used MAF sensor, and installed it, and that got it running again (with it plugged in the way it is supposed to be.) I put in a new Subaru coolant temp sensor, and went out today, and started it, and put it in gear and it did not stall. It was 25 degrees out. I thought we had it solved, since putting it in gear would kill the engine before. Later in the day (still very cold) she took it to drive to school, but only got around 50 yards from the house before it stalled. She said it was bucking and stalled out. It re-started OK, and she let it warm up and drove it to school, very upset. So, it starts, it doesn't stall when put in gear, but now that we are below 30 degrees, it isn't driveable right away. It does smoothly drop in idle from 1500 to 750 as it warms up. I did clean the IAC last summer. Don't know if that could be dirty again so soon. Any ideas from anybody? The thing runs good when warmed up.....it's just so frustrating that it won't run when cold. If I get any good ideas, I might be able to take some parts along to swap when we see her in a week. I do have an extra ecu here that I can try if that makes sense. Thanks for any comments from anybody with similar experience. Quote Link to comment Share on other sites More sharing options...
3Pin Posted January 4, 2012 Share Posted January 4, 2012 Man, it seems like you have covered the bases. Would older leaky fuel injectors cause this? http://www.autotap.com/techlibrary/solving_intermittent_stalling_problems.asp There are a couple other possibilites in this article. Good luck! Quote Link to comment Share on other sites More sharing options...
Fairtax4me Posted January 4, 2012 Share Posted January 4, 2012 Rough running when cold is a typical symptoms of a bad coolant temp sensor. Stalling can be caused by a few things. A sticky Idle control valve, vacuum leaks, various sensors. Start with the easy stuff first, check vacuum hoses, and clean the throttle body and idle control valve. Intake and Throttle Body Cleaner works by far the best for these. Seafoam in the intake works wonders as well. Quote Link to comment Share on other sites More sharing options...
LeolaPA Posted January 4, 2012 Author Share Posted January 4, 2012 I was thinking during the night... what if the new coolant temp sensor that I installed was not right? I guess that is unlikely, since it is new and a Subaru part, not aftermarket. I did check the resistance after it had been in the freezer for a while, and it checked to be 11,000 ohms. My old one was 8,100 ohms. I wish I could find something online about what these should measure below freezing. Quote Link to comment Share on other sites More sharing options...
porcupine73 Posted January 4, 2012 Share Posted January 4, 2012 Yours most likely has an ODBII port, though I'm not sure all '95 soobs got them. If it has one, if you have or can borrow a scan tool, many of those will show you what the ECU is reading for the engine coolant temp. Then if it has been sittting for say 6 or 8 hours or more you can do a reality check in comparing that against ambient. Quote Link to comment Share on other sites More sharing options...
1 Lucky Texan Posted January 4, 2012 Share Posted January 4, 2012 Man, it seems like you have covered the bases. Would older leaky fuel injectors cause this? http://www.autotap.com/techlibrary/solving_intermittent_stalling_problems.asp There are a couple other possibilites in this article. Good luck! yeah - he did well. Any correlation to wet/damp conditions? maybe coil or wires arcing-out. Could there be a Throttle Position Sensor issue? Or fuel pump? Quote Link to comment Share on other sites More sharing options...
porcupine73 Posted January 4, 2012 Share Posted January 4, 2012 HHHHHHHHHmmmmmmm was just thinking.....did you have the battery unhooked at all or did it get low/dead? I think there was a TSB about this era that having the battery unhooked for just a few minutes could cause poor idling. It wanted it unhooked say overnight. Hm...I found this...but I thought I had seen something similar for earlier models too... Rough Idle and Check Engine LightA rough engine idle condition may occur when the vehicle’s battery is disconnected for less than 30 minutes on some 2001 and later Subaru vehicles, up to and including the 2003 Legacy and Baja.The rough idle condition only affects four cylinder, non-turbo vehicles. 2004 model year vehicles may also be affected. Clearing the memory with the Select Monitor will correct this condition.Also, the ECU will most likely clear itself if the battery is allowed to remain disconnected for more than 30 minutes. 1 Quote Link to comment Share on other sites More sharing options...
987687 Posted January 4, 2012 Share Posted January 4, 2012 Just to be sure, how many prongs did the temp sensor you replaced have? There are two of them. One feeds the gauge, one feeds the computer. The one you want to replace is the one with two prongs. Quote Link to comment Share on other sites More sharing options...
naru Posted January 4, 2012 Share Posted January 4, 2012 Bucking is normally fuel starvation. Leaky injectors are more likely to give trouble when warm. I`ve seen intake manifold vaccuum leaks cause a similar problem on other engines. Vacuum leak seals itself as motor warms. I would check fuel pressure.Maybe the pump/filter is marginal. If no gauge availible,at least remove the filter and attempt to blow through it.Or change it. I suspect the new MAF runs the engine slightly richer than the old one thereby ALMOST compensating for the leaness. Quote Link to comment Share on other sites More sharing options...
LeolaPA Posted January 5, 2012 Author Share Posted January 5, 2012 Porcupine73, I do have OBD 11 and have an Acutron tool of some level... not the best, not the cheapest, so maybe I can see if mine will check that temperature like you said. I'm new to using that tool, and pretty much only used it to read codes up till now. Those who mention fuel pump... that's one I don't know about. The funny thing is that it doesn't take real long to get the car warm enough that this stalling goes away. Seems like the fuel pump would continue to cause a problem if it is faulty. On the IAC, since the idle speed drops very nicely and smoothly as it warms up, I figured that shouldn't be a problem, but maybe someone can explain why it might cause a problem. Oh, and the idle is not rough. It is smooth. The only problem is stalling when trying to drive. It idles nice when parked. I did not have the battery disconnected lately... although before Christmas I did replace the battery. It was out for probably 15 minutes at the most. I though I had the problem fixed until it got to the 20's, so I doubt that the battery is it. The coolant temp sensor had 2 contacts, and was the exact same number as the one that was in it. I think I changed the fuel filter a year ago also. A vacuum leak that I am missing somewhere could be a possibility. There are many vacuum hoses and some hard to see. Thanks everyone for the comments so far. I won't see the car again until this Sunday, so I'm all talk and no action until then. Quote Link to comment Share on other sites More sharing options...
porcupine73 Posted January 5, 2012 Share Posted January 5, 2012 Hm. Well I don't think anyone mentioned it yet, and I don't know it would cause what you are experiencing, but some from that era had some problems with the fuel injectors where they would develop ice on the tips in cold weather. I think that was more of a no start, hard starting type issue rather than stalling though. Quote Link to comment Share on other sites More sharing options...
naru Posted January 5, 2012 Share Posted January 5, 2012 (edited) Those who mention fuel pump... that's one I don't know about. The funny thing is that it doesn't take real long to get the car warm enough that this stalling goes away. Seems like the fuel pump would continue to cause a problem if it is faulty. Maybe just long enough for the O2 sensor to warm up and start commanding the mixture richer. If you have live data on your scanner,check to see if the O2 sensor comes alive at the same time the car becomes drivable. I would compare airflow measurements of the 2 MAFs as well. Wouldn`t suprise me if a slightly weak pump/clogged filter exhibited very few symptoms when warm.A one year old filter change is ancient history. Time for a new one,regardless. Edited January 5, 2012 by naru + MAF comparision Quote Link to comment Share on other sites More sharing options...
the3rsss Posted January 5, 2012 Share Posted January 5, 2012 How about the basics? Plugs and wires? New? Quality? Vac. Hoses ok? Sounds like maybe a vac leak. Check pvc hoses and egr valve/hoses for cracks or restrictions. Have you done a compression or vac test? A bad Iac will generally give you a very low or very high idle. I would concentrate on a vac leak. Quote Link to comment Share on other sites More sharing options...
the3rsss Posted January 5, 2012 Share Posted January 5, 2012 Oh BTW...I had a 01 Taurus do the exact same thing. Turned out to be a bad map sensor. I know you put one in but..... Quote Link to comment Share on other sites More sharing options...
porcupine73 Posted January 5, 2012 Share Posted January 5, 2012 '95 Legacy does not have a MAP sensor. Quote Link to comment Share on other sites More sharing options...
Fairtax4me Posted January 6, 2012 Share Posted January 6, 2012 Sure it does. I have two '95s that have MAP sensors. There were some variances in equipment that year, some had MAPs, some didn't. I don't remember the exact details. Quote Link to comment Share on other sites More sharing options...
johnceggleston Posted January 6, 2012 Share Posted January 6, 2012 all legacys 95 - 98 have a MAF, but i was my understanding that they also had a MAP. not right?? Quote Link to comment Share on other sites More sharing options...
987687 Posted January 6, 2012 Share Posted January 6, 2012 I have never heard of, or seen a MAP on any phase1 motors... Quote Link to comment Share on other sites More sharing options...
porcupine73 Posted January 6, 2012 Share Posted January 6, 2012 It does have a pressure sensor. I believe it uses to measure barometric pressure and something else through the pressure sources switching solenoid. Maybe something to do with EGR or the fuel tank pressure when it is doing the fuel system integrity test. But on those era's I don't believe it uses it for measuring/calculating airflow into the engine; they use the MAF instead. The MAP for airflow calculation started around 2000 for Subaru, probably because it is cheaper and they may have perceived it had longer service life than the hot wire MAF's, even though it is arguable that it is not as accurate. Quote Link to comment Share on other sites More sharing options...
LeolaPA Posted January 7, 2012 Author Share Posted January 7, 2012 I replaced the pressure sensor on one of the Subarus we had, but I don't remember if it was this one. Anyway, I used a second hand one. I have a bunch of parts and I can try checking to see if I have one, and try it out. I see in the Haynes manual about the pressure exchange solenoid. So I can look into these areas next. I have not replaced the plugs. The wires LOOK good, possibly replaced sometime by somebody. Wires are so good now compared to what they used to be. If the problem had to do with wet weather, I might check wires, but that's not a factor. Thanks again for the new comments! I will see the car on Sunday. Going to take an ECU and the pressure sensor if I have one. Quote Link to comment Share on other sites More sharing options...
LeolaPA Posted January 9, 2012 Author Share Posted January 9, 2012 Went to see my daughter today. Took along a spare ECU. I swapped it out, but it didn't make any difference. New symptom... last week I had it so that it would go into gear without stalling from cold, but now it is stalling when it is put into gear. The temp was probably in the 40's when I tried it today. I did take a scan tool and wrote down some readings. Then my daughter decided to trade cars, so I will be able to do some different things here at home. It ran fine after warm up to about 140 degrees, and drove fine at 65 on the 50 mile drive home. Quote Link to comment Share on other sites More sharing options...
1 Lucky Texan Posted January 9, 2012 Share Posted January 9, 2012 man, tough um, I'll just offer that, if the knock sensor caused the system to retard to max, i think you could get 'power loss'. Seems like another thread followed along like that. Dunno if it would actually stall when put in gear. won't FreezeFrame data show the knock advance/retard from the OBDII ? Quote Link to comment Share on other sites More sharing options...
Rooster2 Posted January 9, 2012 Share Posted January 9, 2012 Went to see my daughter today. Took along a spare ECU. I swapped it out, but it didn't make any difference. New symptom... last week I had it so that it would go into gear without stalling from cold, but now it is stalling when it is put into gear. The temp was probably in the 40's when I tried it today. I did take a scan tool and wrote down some readings. Then my daughter decided to trade cars, so I will be able to do some different things here at home. It ran fine after warm up to about 140 degrees, and drove fine at 65 on the 50 mile drive home. The ECU seldom breaks. So I am not surprised swapping in a new ECU did not help the problem. Did you replace the cold start sensor?? Quote Link to comment Share on other sites More sharing options...
1 Lucky Texan Posted January 9, 2012 Share Posted January 9, 2012 95 is getting old, has it had plugwires changed? Is it more likely to run poorly when the weather is damp? could be a higvoltage problem. Quote Link to comment Share on other sites More sharing options...
naru Posted January 9, 2012 Share Posted January 9, 2012 how about the basics? Plugs and wires? New? Quality? Vac. Hoses ok? Sounds like maybe a vac leak. Check pvc hoses and egr valve/hoses for cracks or restrictions. Have you done a compression or vac test? A bad iac will generally give you a very low or very high idle. I would concentrate on a vac leak. +1 Quote Link to comment Share on other sites More sharing options...
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