I have a MY99 that has developed a misfire over the last 3 weeks, initially I thought it was the same problem as numerous people have added to another thread in this section but now I am not sure.
The problem shows it self as irratic tickover from almost 0 to 1800 rpm. Sitting at about 35 - 40 mph the car kangeroos but not to violently and when you accelerate in top from 70 upwards you push the throttle and then have to wait what seems ages and then suddenly its off like a rocket. It is also bad if you have accelerated and then come off the throttle and back on.

However I have noticed the lower the fuel the worse it gets and less than a 1/4 of a tank it is virtually undriveable. Once filled up to the brim it is virtually un noticable. Could it be fuel pump? as having more fuel onboard makes it better.

Any Ideas?

 

Andy

My MY95 WRX experiences similar symptoms and these are caused by the wastegate solenoid. It seems worse on cold damp days, or after a good thrashing. I was going to change the solenoid but dealer advised not worth it as the improvement wouldn't be worth the cost (£160). I just fill it full of brake cleaner from time to time when it gets bad, seems to cure it for a while.

Ken

 

Andy,

Can't help, but if you get to the bottom of it, PLEASE let me know, and I'll do likewise. With the exception of the irratic tick-over, you've described my MY99's problem to a tee.
It is however intermittent (thought it had gone away altogether the other week, but this week it's back!), and always seems to go away when a service is pending, hence the dealer never finds anything.
Good luck!
Paul

 

I have an MY99
Had a intermittent problem with lack of boost coming out of corners, turned out to be fuel starvation due to low fuel level in the tank Not the same i konw but it rang a bell when i read that your problem was worse with low fuel
Could be muck in the bottom of the tank, fuel guage reading high, blocked filter or a fuel pump problem

Should be a warranty thing?!?

 

Andy

Check out recent previous post 'MYOO surging problems' where someone ( think his name was Jim something) said he had the same problem when fuel tank was low. He said it went away when he ran with no cap on....(though he did get a cold head )

Denis