Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: pauls on 12 May 2015, 15:21:27

Title: hesitation on throttle / gearbox response
Post by: pauls on 12 May 2015, 15:21:27
This is difficult to explain but sometimes when you give it bootfull it will think about it then go, other times it will change gear then change again. No thuds or code since replacing the gearbox and gearbox ecu. Perhaps mr Chrisgixer can word it better as he has experienced the fault. Also sometimes when you boot it then lift off it feels like the revs dont drop.

Probably a silly thought but what controls the throttle peddle. was just thinking perhaps engine/gearbox is being told the wrong thing so not sure what to do.
Title: Re: hesitation on throttle / gearbox response
Post by: lesv6 on 12 May 2015, 15:28:25
Your right foot controls the throttle pedal ;)

first try cleaning throttles and make sure spindles are free moving and not tight
Title: Re: hesitation on throttle / gearbox response
Post by: chrisgixer on 12 May 2015, 15:45:04
Your right foot controls the throttle pedal ;)

first try cleaning throttles and make sure spindles are free moving and not tight

It's drive by wire ::)

Title: Re: hesitation on throttle / gearbox response
Post by: chrisgixer on 12 May 2015, 15:47:26
Any engine codes? Pedal trick?

It could just be the start of a misfire, or some other engine management hic up.

If it's a slight misfire, it could see the reduction in torque and change up, thinking you've throttled off. For example.

Did it get software update?
Title: Re: hesitation on throttle / gearbox response
Post by: pauls on 12 May 2015, 15:55:16
No codes using pedal trick.
No updates all upto date.

Thinking about misfire would this be caused by old spark plugs. Couldnt see anything in the history for changing them since 2007.
Title: Re: hesitation on throttle / gearbox response
Post by: lesv6 on 12 May 2015, 17:00:18
Your right foot controls the throttle pedal ;)

first try cleaning throttles and make sure spindles are free moving and not tight

It's drive by wire ::)
I know, same as my 3.2
as i said clean throttles and spindles first, could be sticking. remove bagpipes and unbolt throttle bodies. if no improvement could be iffy tps
Title: Re: hesitation on throttle / gearbox response
Post by: TheBoy on 12 May 2015, 18:10:44
I would also ensure breathers and throttles are spotless. Then I would be looking it seeing if the trims are drifting out
Title: Re: hesitation on throttle / gearbox response
Post by: chrisgixer on 12 May 2015, 20:20:03
Your right foot controls the throttle pedal ;)

first try cleaning throttles and make sure spindles are free moving and not tight

It's drive by wire ::)
I know, same as my 3.2
as i said clean throttles and spindles first, could be sticking. remove bagpipes and unbolt throttle bodies. if no improvement could be iffy tps

You know, yet post that that the drivers foot sets the throttle. It  doesn't , the Tps does. ::)
Title: Re: hesitation on throttle / gearbox response
Post by: chrisgixer on 12 May 2015, 20:23:01
No codes using pedal trick.
No updates all upto date.

Thinking about misfire would this be caused by old spark plugs. Couldnt see anything in the history for changing them since 2007.
Possibly. It might be coil pacs breaking down. It could also be a number of other things. I'd be pulling the drivers coil PAC for a look see. Along with the other suggestions.

..although I drove an omega with blocked breathers for some time. It didn't behave like this does. It's a drop in power. But why...?
Title: Re: hesitation on throttle / gearbox response
Post by: TheBoy on 12 May 2015, 20:56:52

..although I drove an omega with blocked breathers for some time. It didn't behave like this does. It's a drop in power. But why...?
On these, shitty breathers tend to give stickiness to DBW throttles (or in extreme cases, actually knacker the gears in the servos - but I've only ever send that once myself), which was my reasoning for suggesting cleaning.

But I'm not convinced in this case, hence wanting to see trims (and/or MAF at point it fails)
Title: Re: hesitation on throttle / gearbox response
Post by: zirk on 12 May 2015, 21:00:24
Is it the same with the TC off ?
Title: Re: hesitation on throttle / gearbox response
Post by: pauls on 12 May 2015, 21:10:55
I have cleaned the breathers, all pipes and box. I havnt tried it withe the tc off. Today I noticed the indecisive gearchange when engine was cold, I drove about half a mile to the a40 on the way down the on ramp hit the peddle and it seemed to change twice. After about 30 mins of driving around went back on the a40 pressed on to just above 80 then lifted off and for a second or two nothing happened then the revs dropped and the speed dropped.
Title: Re: hesitation on throttle / gearbox response
Post by: chrisgixer on 12 May 2015, 21:19:30

..although I drove an omega with blocked breathers for some time. It didn't behave like this does. It's a drop in power. But why...?
On these, shitty breathers tend to give stickiness to DBW throttles (or in extreme cases, actually knacker the gears in the servos - but I've only ever send that once myself), which was my reasoning for suggesting cleaning.

But I'm not convinced in this case, hence wanting to see trims (and/or MAF at point it fails)

This is at wot in third iirc, or was it in second... Certainly wot, at a tad over 5k rpm. So given the road in question, more likely second.
So not near rev limiter.
Not near a gear change point.
Not during throttle movement. (Assuming no fault of course, as it should be wide open and the symptom would suggest it's trying to close if a Tps fault)
Not near a multi ram movement. (Iiuc?)

Basickly engine at full load at 5,200 odd rpm. Slight hesitation/drop in load until 5,500 and off it goes again.

I'd be looking at engine management I think? O2 or Maf or spark. ....fuel filter?

Something breaking down at full load anyway.

There is a concern the box is trying to change gear. Which is sort of feasible.  Box replaced with matching ecm from same dinar vehichle as the box. Known good.

Has the fluid level been re checked since the box change Paul..?
Title: Re: hesitation on throttle / gearbox response
Post by: chrisgixer on 12 May 2015, 21:22:01
I have cleaned the breathers, all pipes and box. I havnt tried it withe the tc off. Today I noticed the indecisive gearchange when engine was cold, I drove about half a mile to the a40 on the way down the on ramp hit the peddle and it seemed to change twice. After about 30 mins of driving around went back on the a40 pressed on to just above 80 then lifted off and for a second or two nothing happened then the revs dropped and the speed dropped.

This is a new symptom, to me anyway. I haven't experienced this. Would you say the revs dropped as if throttle off?
Title: Re: hesitation on throttle / gearbox response
Post by: pauls on 12 May 2015, 21:29:47
I have cleaned the breathers, all pipes and box. I havnt tried it withe the tc off. Today I noticed the indecisive gearchange when engine was cold, I drove about half a mile to the a40 on the way down the on ramp hit the peddle and it seemed to change twice. After about 30 mins of driving around went back on the a40 pressed on to just above 80 then lifted off and for a second or two nothing happened then the revs dropped and the speed dropped.

This is a new symptom, to me anyway. I haven't experienced this. Would you say the revs dropped as if throttle off?

Sorry worded it wrong revs dropped and speed dropped as there should, it just seemed to hold onto the revs a bit longer than expected when I lifted off. Hence my question could the throttle stick..
Title: Re: hesitation on throttle / gearbox response
Post by: chrisgixer on 12 May 2015, 21:36:41
Investigate that immediately. Throttle sticking is not good. Be ready to turn the ignition key off if it does stick. Maf or air leak otherwise.

However that's the opposite of the symptom at wot.
Title: Re: hesitation on throttle / gearbox response
Post by: chrisgixer on 12 May 2015, 21:40:12
Ps I have a spare Maf if you need to try it.
Title: Re: hesitation on throttle / gearbox response
Post by: pauls on 12 May 2015, 21:43:26
I will keep a eye on it and let you know :y
Title: Re: hesitation on throttle / gearbox response
Post by: lesv6 on 12 May 2015, 23:55:44
Your right foot controls the throttle pedal ;)

first try cleaning throttles and make sure spindles are free moving and not tight

It's drive by wire ::)
I know, same as my 3.2
as i said clean throttles and spindles first, could be sticking. remove bagpipes and unbolt throttle bodies. if no improvement could be iffy tps

You know, yet post that that the drivers foot sets the throttle. It  doesn't , the Tps does. ::)

read the posts properly.  op asked "Probably a silly thought but what controls the throttle peddle. was just thinking perhaps engine/gearbox is being told the wrong thing so not sure what to do"

throttle PEDAL is controlled by your right foot.  u got no sense of humour?
Title: Re: hesitation on throttle / gearbox response
Post by: chrisgixer on 13 May 2015, 00:00:46
Your right foot controls the throttle pedal ;)

first try cleaning throttles and make sure spindles are free moving and not tight

It's drive by wire ::)
I know, same as my 3.2
as i said clean throttles and spindles first, could be sticking. remove bagpipes and unbolt throttle bodies. if no improvement could be iffy tps

You know, yet post that that the drivers foot sets the throttle. It  doesn't , the Tps does. ::)

read the posts properly.  op asked "Probably a silly thought but what controls the throttle peddle. was just thinking perhaps engine/gearbox is being told the wrong thing so not sure what to do"

throttle PEDAL is controlled by your right foot.  u got no sense of humour?

Nope. Not when it comes to lack of manors. Les! Costs nothing. :)
Title: Re: hesitation on throttle / gearbox response
Post by: lesv6 on 13 May 2015, 00:04:52
get a life pal, its too short
Title: Re: hesitation on throttle / gearbox response
Post by: chrisgixer on 13 May 2015, 00:16:45
get a life pal, its too short

Agreed. Pal!
Title: Re: hesitation on throttle / gearbox response
Post by: 05omegav6 on 13 May 2015, 00:32:31
Could be worse, he could have called you Geez... all though that's a bit Crawley :D

If only Dbug were here, then we could have a proper row rather than this half arsed shyte ::)
Title: Re: hesitation on throttle / gearbox response
Post by: 05omegav6 on 13 May 2015, 00:34:45
In the meantime, how many miles has the car covered in Pauls ownership? Could it simply be that the ecu is still adjusting to the change of use/driving style?

Have a spare 3.2 ecu here for testing purposes if required :y
Title: Re: hesitation on throttle / gearbox response
Post by: pauls on 13 May 2015, 09:03:48
In the meantime, how many miles has the car covered in Pauls ownership? Could it simply be that the ecu is still adjusting to the change of use/driving style?

Have a spare 3.2 ecu here for testing purposes if required :y

Cars only covered a couple of thousand miles
Title: Re: hesitation on throttle / gearbox response
Post by: 05omegav6 on 13 May 2015, 10:11:33
It should have adjusted to your driving style by now :-\
Title: Re: hesitation on throttle / gearbox response
Post by: Kevin Wood on 13 May 2015, 10:23:16
A DBW throttle can't stick unless the pedal itself sticks. If the throttle body sticks, the ECU will spot that the position of the throttle isn't following the position of the pedal and shut down the engine by other means.

Not saying a slightly sticky throttle wouldn't cause it to feel a bit laggy, but it won't carry on pulling like a train with no throttle pedal input.

Sounds like a fault that words can't adequately describe, IMHO. :-\
Title: Re: hesitation on throttle / gearbox response
Post by: chrisgixer on 13 May 2015, 18:21:42
In the meantime, how many miles has the car covered in Pauls ownership? Could it simply be that the ecu is still adjusting to the change of use/driving style?

Have a spare 3.2 ecu here for testing purposes if required :y

Cars only covered a couple of thousand miles

It's not a normal thing. I've driven a few other members cars on test drives and this was immediately obvious as not quite right.

Needs a tech 2 session IMO. With a one of the guys in here.


As another thought. Just check the brown plugs behind the battery are securely together.
Title: Re: hesitation on throttle / gearbox response
Post by: pauls on 16 May 2015, 15:42:05
Question would loose battery cables cause these issues... Only ask because this morning checked both and both where loose so I tightened both then redid the breather box and cleaned the throttle..neither that dirty have seen a lot worse.

I have just come back from a 20 min run up the m40 slowing down to about 40 then blasting upto 80+not able to max revs as to much traffic and all seems good. slow drive around town and it seems to be fine.

Will have to give it a couple of days to see.
Title: Re: hesitation on throttle / gearbox response
Post by: chrisgixer on 16 May 2015, 16:03:20
Could do. But I'd of thought you'd see other systems cutting in and out as well tbh. Or at least flickering...? :-\