club.liberty.asn.au

hey guys,

i've noticed that sometimes the car jerks a bit when i take off and there is a bit of a pause then it sort of goes but it takes about a second before i takes off.
does anyone else have this problem or should i hit a subaru dealership up about it?

Cheers, Alex.

What gear is this in.
I vaguely recall a thread about some people experiencing something similar in 2nd or 3rd gear....I was also experiencing something like that, a sort of hole in the power curve. I just reset my ECU by unplugging the battery for 10 mins and it seemed to sort itself out. Might be worth a try first

Sounds more like the electronic throttle being far from perfect.

Apparently the MY07 GTB's onwards have a quirk with the ECU in running closed loop too long while your trying to give it stick. Closed loop operation should only be used during light throttle applications and idle, then the ECU runs open loop which then relies on feedback from the sensors to run the car correctly with demand. With the stock tune the closed loop runs too long causing a dip in torque early on and then recovers itself when it changes to open loop.

Is there a chance that this 'lag' is due to this? Another thing you could try is a Subaru upper engine cleaner service, its a can which you spray half into a vac line to the intake manifold with the car off, let it sit then run the car and disperse the ammonia and junk cloud. After that you just run the rest of the can through with the engine running. Give that a go, might fix it.

It sounds like that's what it is Jim. I ran a can of upper engine cleaner last service (2,500kms ago) so it's not that the car needs that. How do I fix this closed loop open loop prob? I heard from someone I think a tune will fix it?

PAZ04U wrote:It sounds like that's what it is Jim. I ran a can of upper engine cleaner last service (2,500kms ago) so it's not that the car needs that. How do I fix this closed loop open loop prob? I heard from someone I think a tune will fix it?

Yep, it does. If you like to see the horrible OEM Subaru tune v post tune check out my car build thread.

http://forum.liberty.asn.au/viewtopic.php?f=10&t=5714&start=135

You can fix it by retuning.

The delay or hesitation you speak of will be gone.

Does this CL/OL delay only affect the facelift ECUs, or does it apply to pre-facelift too?

Hey Tony, what is romraider? I'm a newbie in this sort of stuff..

Cheers, Alex.

PAZ04U wrote:Hey Tony, what is romraider? I'm a newbie in this sort of stuff..

Cheers, Alex.

ECU table software, has definitions to read and alter values to your ECU flash.

I had a few issues with mine like this - spend some minutes at very low throttle in traffic, light on/off etc, and then when you plant the foot it choked. 2 things happened - I complained at a service, they said they found a kinked/flattened hose and fixed it, AND I reset ERCU by disconnecting battery. When I asked about the hose they showed me a small bore (8-10mm 0OD)hose stuck between two bigger hoses - suspect its connected to wastegate. I would try the ecu reset - quick, only downside is reloading radio presets.
jp 08 gtb 6mt wagon..

i doubt it would have been the wastegate hose, if that was the case it would have been unlimited boost FTW!!

Could even be something as simple as a dirty AFM. I had a very similar thing happen to my car (chocked on take off etc). Booked it for a re-tune and service and got told it was only the AFM and it needed a good clean. Fixed the problem straight away and saved me $$$. Just putting it out there as a possible cause.
So what did it end up being anyway? Have you got sorted now?