Engine hesitation/flat spot (Liberty 2.0R)

[calais]

It came back after 3 or 4 minutes of running first thing in the morning.

I am in the middle of cleaning my avcs filter now, it was choked with all kinds of sh*t.... so who knows.... I might get lucky.

If not, its off to the gurus at the Automotive Technical Centre in Penrith tomorrow afternoon.

Im also waiting for it to be dark as around here, so I can check each coil and plug assembly for a random light show...... Might get lucky there too..... because this hesitation is god awful, worse than it ever was.

[klam]

It came back after 3 or 4 minutes of running first thing in the morning..

no no.. I meant yesterday or before when you last time turned the engine off, what was the drive ?

[Jeffreyy]

I am not sure how to upload photos from
my iPhone! But I will let you know the outcome!

That sucks about how it returned!

[Jeffreyy]

Calais did the problem return with the new or original egr valve?

[Kormoran]

So far so good since seeing JFM to get the TB cleaned! After 1 tank of city driving and a 1300km weekend trip to NSW, the hesitation hasn't returned. I had 4 people in the car and a full boot (wheels were tucking about a half inch under the guard )

There were plenty of hills that required wot at low rpm and in the past that's what I found brought on the hesitation.
Should also mention I switched from 10w30 to 5w30 semi synth oil 3 weeks ago.


Fingers crossed, Ill give it a few more weeks and update again.

Cheers!

[calais]

G'day Guys,

I didnt make it to the mechanics today, just flat out with work.

I have decided to rest myself from this issue for a little while at least. I drove the subaru down to my storage space, fired up my honda and swapped them over.

Just feeling a little deflated with it all to be honest.

If work calms down in the next two weeks, I'll swap them over again and get to work on the liberty.

Mind you, I did miss my accord euro, its a damn nice car in its own right, even if it doesnt have the 'personality' of the liberty.

FWIW the hesitation came back with the original (cleaned) egr and after just normal driving with no cruise control used previously...... I did reset the fault codes for the trip to the storage unit and it drive faultlessly....... Thats 'personality' for you.....

[dmh87]

Great to hear Kormoran! The worst feeling in the world is when having to take passengers - the extra load on top of the 2.0NA is already noticeable but having the hesitation play up as well is a pita.

Lucky you've got the honda to swap into calais, hopefully will get you some time off to relax and concentrate on other important things.

All you guys have been very helpful so far sharing your experiences and I just would like to say thanks for sharing!
On another note I just remembered from the top of my mind that sometimes when the hesitation comes back, I would sometimes give it a good drive, high rpms, higher temps to try and burn out any carbon left sitting around - sometimes it would feel a bit less sluggish after this, other times it doesn't or my trip will be too short to see the difference. The subaru UEC is great during my interval services (the amount of smoke that comes out is surprising) and it drives perfectly afterwards.

If anything else comes up I'll be sure to put a post up. I'm driving back to Sydney for the Christmas holidays so we'll see how my car handles after that.
Maybe even catch up with you guys if there's an opportunity.

[klam]

Mine is back as well after a week. No matter how many upper cleaners I run through (2 last time, one through the butterfly and one through one of the vacuum hoses) changed oil to 5w/30 at the same time. Pure frustration..I'm due to regobrenewal soon and will have to decide whether I keep it or not...it struggles heavily into hills or pedal-to-floor scenarios..must be the engine load calculations.. Btw this time it came back in the middle of driving, went up the hill and suddenly the ECU hesitated and it was all back.
Was driving like a bogan afterwards with revs above3500 to keep it going horrible.

[klam]

I have an update on this .. I took out the butterfly, I had some green stuff on it again (what that could be??), and to take it out, you have to disconnect a position and map sensors (it has 'boost sensor' written on it) and once plugged back in, the car was driving faultlessly again and I DIDN'T reset the ECU. so this might indicate a problem with a throttle butterfly of the sensor I reckon?

Also that green stuff.. could that be from coolant? it looks very similarly coloured.. it was from inside the butterfly, not from the intake side. can someone inspect theirs? ... inspection at my friends place showed that I also have a problem with water pump.. how nice..looking for 700$ job.. how pleasant is that.. car drives like shit sometimes, you don't know what it is, but you have to fix something else..

[TimN]

Things I've found that seem to bring on the hesitation...not the most mechanically minded, but from experience its always one of two things:

*A descent on the pacific hwy at just over 2000 rpm in 4th, followed by a mild hill where I ease the throttle back on slowly...always seems to trigger it. On the upgrade, the power kicks back in until it reaches 2500, then suddenly...a startling drop off in power, and a change of engine note (no more subi rumble), and taking FOREVER to get from 2500 to 3000 rpm...above which the power slowly eases back on again.

*Trying to take off fairly quickly at the lights, without riding the clutch enough to keep revs up (always when I'm next to an embarassingly slow car trying to cut in on me at a merge...which then succeeds). The car just dies and takes FOREVER to reach 2000 rpm, then has a hopeful burst of power 2000-2500, then dies 2500-3000. From that time onwards, the 2500-3000 power loss occurs.

For now, I resort to slow take offs, and if necessary, just boot it after reaching 2000rpm. Ive started to take the hill in question in 5th instead of 4th. It sounds bizarre but I have had no problems since. Hmm....

[klam]

Tim, to me that looks slightly different to what I (perhaps other guys as well) experience..

Is anyone with flatspot free car willing to do a quick swap or throttle body (3minutes job) to see if it's the position sensor problem or not?

M

[Jeffreyy]

I had a look at my mates 2.0r for the crack in the exhaust near the oil filter and their was none! His exhaust looked like it was made out if a different material!

I also was going to try his maf sensor in mine car but his 2006 impreza 2.0 had a complete different setup engine bay to my 2006 impreza 2.0 r

Has anyone tried a new maf sensor to solve the problem? I have cleaned mine and it has helped abit!

[dmh87]

Hey Jeffreyy I haven't had the need to replace my maf sensor but I have cleaned it maybe 2-3 times over the past year or so mainly after long long drives in the country.

klam, I'm more than happy to do a quick swap with you but it will probably have to wait to the end of the year or early next year. I'm still in Melbourne and won't be back in Sydney until the Christmas holidays.

[klam]

message sent dmh. thanks heaps.

btw I'm ordering a new coil pack to see if it resolves the problem. currently running flatspot free (it went away on its own).

[Jeffreyy]

Just a question: is it possible to buy a new ecu or performance ecu! I know we can't tune our Ecu! I am convinced it's the Ecu cause the whole problem