Last post on Oct 09, 2011 at 4:20 PM
You are in the Subaru Legacy & Outback
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Subaru Legacy, Engine, Sedan, Wagon
#1 of 31 Hesitation problem
Feb 17, 2007 (8:13 am)
Hello, I have a 1998 subaru legacy gt wagon 2.5 auto. When taking off from a stop it has a hesitation like the engine tries to almost die out then the rpms comes up and it's fine. It does not do this all the time just here and there. Sometimes the check engine light comes on and when it does it and reads knock sensor. What do i have to replace to get it to stop doing this?
#2 of 31 Re: Hesitation problem [carnut114]1998 subaru legacy gt wagon 2.5
Feb 17, 2007 (5:36 pm)
This is about a 1998 subaru legacy gt wagon 2.5
#3 of 31 Re: Hesitation problem [carnut114]1998 subaru legacy gt wagon 2.5 [carnut114]
Feb 18, 2007 (12:44 am)
It sounds like either ignition or fuel delivery problems. If it is fuel, a good start point is to add a bottle of top engine cleaner to clear injectors etc. and possibly shift to a high octane, detergent added fuel such as Shell Optimax or BP Ultimate (there will be something similar in the US).
If that does not clear it, try looking at plugs (look up what clean plugs look like on the net) and possibly replacing plug leads.
After this stage, you are in to spedning some money with a good service agent. Ultimately, this may be the most economical route to investigating the problem.
#4 of 31 Re: Hesitation problem [carnut114]1998 subaru legacy gt wagon 2.5 [carnut114] [grahampeters]
Feb 18, 2007 (9:29 am)
Hello, I have decarbed the engine twice with sea foam ( disolves carbon buildup) and one other fuel injector cleaner. I have put new boch platinum spark plugs, new fuel filter, pcv valve. The spark plug wire look like new. I think it might me a throttle position sensor or a map sensor. Possibly a mass flow air sensor not sure.
#5 of 31 Re: Hesitation problem [carnut114]1998 subaru legacy gt wagon 2.5 [carnut114] [grahampeters] [carnut114]
Feb 21, 2007 (9:14 am)
If the wires are original, they're 9 years old now. Swap them out even if they do look new.
Next thing to try would be the ignition coil, about $80 on-line.
My '98 Forester is running much better after those changes. A chipmunk had chewed my wires (!), but it's running smoother than even before that happened.
#6 of 31 Re: Hesitation problem [carnut114]1998 subaru legacy gt wagon 2.5 [carnut114] [grahampeters] [carnut114]
Feb 25, 2007 (3:43 pm)
Try to also clean the throttle body. Pull out the air filter where it attaches to the throttle and inspect for sludge or builup as it could possibly create the effects that you are experiencing. This could be a cheaper route to solving your problem before you make any other expensive purchases in trying for a resolution. If you have any luck with this let me know as i had similar problems.
#7 of 31 Re: Hesitation problem [carnut114]1998 subaru legacy gt wagon 2.5 [carnut11
Apr 09, 2007 (11:47 am)
Any progress on this? I'm having the exact same issue!!
#8 of 31 Re: Hesitation problem [carnut114]1998 subaru legacy gt wagon 2.5 [carnut11 [benmullin333]
May 14, 2007 (1:36 pm)
Me, too. frequent stalling out of standing position. and a pretty loud "clank" when releasing clutch. Bucking in the engine, too, which is driving me crazy.
#9 of 31 Re: Hesitation problem [carnut114]1998 subaru legacy gt wagon 2.5 [carnut11 [benmullin333] [pvonhaam1]
May 31, 2007 (5:14 pm)
I have had it for some time now. Every once in a while, I will press on the gas, and just wait for the Outback to decide to proceed. It is usually in my driveway first thing in the morning. Any other time, it is in parking lots etc.
#10 of 31 Re: Hesitation problem [carnut114]
Jun 12, 2007 (11:19 am)
Having the same problem with a '93 legacy except in this case it is a bit more noticeable. The car idles ok, but when you try to give it gas it bogs down. If you play with the gas pedal it will rev up but if you put it in gear, forget it. We've swapped out the TPS, IAC, MAF, and the knock sensor. We've cleaned out the throttle body and the intake manifold. At this point, we're at a loss. We've also swapped out the computer to no avail. I know the injectors are firing but could they be clogged up beyond cleaning or might the fuel rails be an issue? Any further advice would be greatly appreciated. Thanks!