Gentz Posted April 21, 2010 Share Posted April 21, 2010 I previously owned a 2000 model Outback with 2.5L engine and auto trans. This car had a serious but intermittent problem with hesitation off the line from a stop, usually only when I really needed to get out of the way. I have since sold the car and never got any codes off of it. Recently I test drove a 2006 2.5L Outback with auto at a Subaru dealer which did the same thing from every stop. What is the reason for this? I know that this has come up on forums many times in the past and I have seen many opinions but is there a single definitive answer yet? My present 1999 Forester does not have this problem although it is old and tired and has other problems. I am looking at purchasing a newer vehicle and the answers to my above questions will probably effect my purchasing decision. Quote Link to comment Share on other sites More sharing options...
Legacy777 Posted April 21, 2010 Share Posted April 21, 2010 Can you describe the hesitation a little more? I know my 90 Legacy had some intermittant issues with hesitation. Sometimes it was more noticable. I kind of attributed the issues to the trans being old. How many miles were on these other cars, the 2000 & 2006? Quote Link to comment Share on other sites More sharing options...
Gentz Posted April 21, 2010 Author Share Posted April 21, 2010 The hesitation that I am talking about is from a stop only and pushing the accelerator down hard and then having nothing happen for 2 - 3 seconds. Then after the 2 - 3 second delay strong normal-feeling acceleration. The 2000 Outback did it from brand new with approximately 600 miles. The 2006 had about 100k on the ODO. Quote Link to comment Share on other sites More sharing options...
Legacy777 Posted April 23, 2010 Share Posted April 23, 2010 I would say that is related more to an engine management issue. When the engine is at idle and you floor it, there's a huge in-rush and demand for air in the engine. The ECU can't rely solely on the MAF sensor to let it know how much air is coming in. It also relies on the throttle sensor, and will adjust fuel enrichments accordingly to help the engine compensate. From my own experience with my aftermarket engine management system, the issue you are probably having is due to over-enrichment, and the engine is bogging out. I'm not sure if there's anything you can do about this. Subaru might be able to reflash the ECU if there's newer programming out there. One thing you can do to try and test this theory is to brake with your left foot, and depress the accelerator gradually with your right foot. Once engine RPMS have risen above idle, let off on the brake and continue depressing the accelerator. Quote Link to comment Share on other sites More sharing options...
Setright Posted April 24, 2010 Share Posted April 24, 2010 I am with Josh on the causation. Isn't it possible to press the throttle down in a more progressive manner? When you snap the throttle open, the flow in the intake must be stifled..almost stopped. A smoother motion will allow the air in the intake to accelerate. Quote Link to comment Share on other sites More sharing options...
Gentz Posted April 27, 2010 Author Share Posted April 27, 2010 hmmm... Yes engine management, but not bogging down. More like no increase in fuel for a couple of seconds. That's a !very! long time to be sitting still when you are trying to get out of the way of an 18 wheeler that "came out of nowhere". I do not normally drive by snapping the accelerator to the floor but there are times when it is critical to be able to do this and get some kind of a response. This is definitely not a normal type of response to throttle. Maybe it is not getting a signal or the correct signal from the TPS or MAF? I have also seen some theories that it might be the knock sensor but that just does not seem likely to me. Quote Link to comment Share on other sites More sharing options...
sparky11 Posted April 27, 2010 Share Posted April 27, 2010 don't forget that the 2005 is also a throttle by wire -- no mechanical connection to the engine throttle body. Quote Link to comment Share on other sites More sharing options...
Gentz Posted April 27, 2010 Author Share Posted April 27, 2010 Did not realize they went to throttle by wire in 2005. You sure? Quote Link to comment Share on other sites More sharing options...
Legacy777 Posted April 28, 2010 Share Posted April 28, 2010 Yup, drive by wire was introduced in the 2005 Legacy. Quote Link to comment Share on other sites More sharing options...
740gle Posted April 29, 2010 Share Posted April 29, 2010 I just did test drive a very nice CPO 07' Legacy wagon with AT, and that was precisely the reason why we did not buy it... I am afraid, it is a problem with the way it is tuned and geared by design, I've seen it before in a similar model Legacy loaner both were low miles, , that I've got when my 02' was in for service, and the same in the brand new that I test-drove... The engine does not seem to be starved of anything - it revs up to 4k rpm, but the thing just does not move, trans is slipping. If it was a manual, I'd say the clutch was slipping. The 2010 Outback with CVT that I had a achance to drive as a loaner did not have it, very nicely geared actually... Just my $0.02.... HTH Btw - is 6cyl. OBW suffering from the same problem...??? Quote Link to comment Share on other sites More sharing options...
Legacy777 Posted April 29, 2010 Share Posted April 29, 2010 My ex had an 06 Outback wagon with the 6 cyl, and it didn't seem too bad. It would get out of its own way. I never noticed the problem you described. Quote Link to comment Share on other sites More sharing options...
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