Uneven tickover and judders under accel

[phil]

I get an uneven ticker but only when the car is between cold and warmed up. Alos under accleration load in higher gears it judders like whellspin but more electronic, but this is ok if at higher revs and is worse when cloder it goes away when engine is hot, ie after hour drive. feels like stutruing.

Its not the Electronic Throttle Unit again is it I had mine replaced about a year and a half ago and it use to be similar

What warranty should i get from main dealer for this??

[Vikingxl]

Warranty on the Etm is twelve months i think and it could be that again.Did you have the pedal changed as well?

[phil]

no pedal is the same

[Vikingxl]

Mine was still running a bit strange and vt replaced the pedal as it has some sort of electronics as well and they recommend changing it at the same time as the etm and mine flies now might be worth a look.

[LeeT5]

Its not the Electronic Throttle Unit again is it I had mine replaced about a year and a half ago and it use to be similar

What warranty should i get from main dealer for this??

:slap: Just because it was new a year ago doesnt mean it's not faulty now!!!
Think about it....... :B_blite:

Parts are only garanteed for one year, however if you can produce the invoice and it is the throttle unit at fault then they may give you a heavy discount towards a new unit.

[volvotuning]

I get an uneven ticker but only when the car is between cold and warmed up. Alos under accleration load in higher gears it judders like whellspin but more electronic, but this is ok if at higher revs and is worse when cloder it goes away when engine is hot, ie after hour drive. feels like stutruing.

Its not the Electronic Throttle Unit again is it I had mine replaced about a year and a half ago and it use to be similar

What warranty should i get from main dealer for this??

Any fault codes?

Adam.

[phil]

No nothing showing up

It alkso seems a bit intermittant happenbs more some days that others but is always in the time between when the engine is cold and fully warmed up almost like its dropping the tick over down too early before the car ahs warmed up.

When it was the ETM before it was having an uneven tickover all the time, unless this is just how it starts

[LeeT5]

No nothing showing up

It alkso seems a bit intermittant happenbs more some days that others but is always in the time between when the engine is cold and fully warmed up almost like its dropping the tick over down too early before the car ahs warmed up.

When it was the ETM before it was having an uneven tickover all the time, unless this is just how it starts

Hmmm, need to see the car really. Where you live?

[phil]

sheffield

wierd though today pulls fine under acceleration but still uneven tickover just before its fully warmed up like the auto choke, is there one? cuts out too early

[SaffronC70]

Mine has done this forever. Two new ETMs. Rica. TME.

However, mine is fine 9 out of ten times.

Before you start the engine, try opening the throttle WOT a few times (with the key turned a few times on ignition).

The search continues !

Chris

[LeeT5]

sheffield

wierd though today pulls fine under acceleration but still uneven tickover just before its fully warmed up like the auto choke, is there one? cuts out too early

Too far for me m8.

You need the car looked at. Could be a poor earth, could be anything¬¬

[glock19]

The regulator at the fuel rail can give you such fault. It's supposed to hold fuel inside (and maintain a certain pressure) even though the engine (fuel pump) is turned off so that in the event of a morning start or after a long stop, ample fuel can still be supplied to the combustion chamber immediately. If it's faulty, the fuel pressure drops drastically and all the faults mentioned points to this.

Why not let the ignition be turned and not cranking it for a while to let the pressure build up in the morning ? See if this improves the situation ?

[LeeT5]

The regulator at the fuel rail can give you such fault. It's supposed to hold fuel inside (and maintain a certain pressure) even though the engine (fuel pump) is turned off so that in the event of a morning start or after a long stop, ample fuel can still be supplied to the combustion chamber immediately. If it's faulty, the fuel pressure drops drastically and all the faults mentioned points to this.

Why not let the ignition be turned and not cranking it for a while to let the pressure build up in the morning ? See if this improves the situation ?

Err!!...Correct me if i'm wrong but i think the above statement is incorrect. (please do trout slap me if i'm talking bolox), i digress....

The regulator is not designed to 'hold fuel and maintain a certain pressure', That is the job of the fuel pump. The fuel pump will prime the fuel lines on ignition 'on' then stop. Once the engine is cranked then the fuel pump continues to pump fuel at the given rate at which it is set. This fuel pressure will always be over and above demand otherwise the engine would cut out and you would get cavitation in the fuel lines.

The regulator's job is to hold back or allow more fuel depending on load conditions, cold start, full throttle etc. Therefore if what i have said is correct or there abouts then i cant see how the regulator would give you the symptoms above. (VT please feel free to but in....)
As for cold starts, the fuel line is a closed, pressurized loop and so fuel cannot leak back otherwise air would form in the fuel lines (not good). The fuel pump merely pressurizes the line again once ignition is in the 'on' position to ensure enough fuel available for cold starting - hense why so many ppl flood their cars cos they crank the engine b4 fuel lines have pressurised causing a weak mixture injected and then a non start situation. The fuel then that has been injected, borewashes the pistons and subsequent cranking of the engine results in more fuel added to a combustion chamber with little or no compression. ie Non start. :slap:

NB. VW overcome this situation by priming the fuel lines apon opening the drivers door! (Golf 4, bora, passat drivers speak up) You can hear the pump priming when the door is opened...Very clever!!

[phil]

car now picks up fine under acceleration ( ive not changed anything!) but still uneven tickover only between when engine cold i(when its fine) and then fully warmed up (its fine again)

I may try a plug change see if that helps?

[phil]

took car into volvo dealer and they couldn't find anything. So i told em how to find it and they finally did after taking car overnight

They replaced a Fuel Pump Relay which often shows up as fault on my car but makes no difference to anything as ive replaced it a number of times myself and according to them this fixed it

It didnt it still does it just the same like i expected

I dont think they want to admit its the etm going again like i told em

Why are dealers so incompetant?

Now I have to wait till it completely fails again with the etm warning light coming on and limp home mode or worse

[volvotuning]

Did you ask them about a cold start software update? I know of several cars that had cold start problems that were cured with a software update for the ECU.

Adam.

[Babybadger]

car now picks up fine under acceleration ( ive not changed anything!) but still uneven tickover only between when engine cold i(when its fine) and then fully warmed up (its fine again)

I may try a plug change see if that helps?

Just a thought, if this system is the same as my 1995 855 , it could be the Fuel gas recirculating system. This I know absolutely nothing about except it takes the fuel vapours and recirculates back to the fuel tank. VT can you explain?

[LeeT5]

Just a thought, if this system is the same as my 1995 855 , it could be the Fuel gas recirculating system. This I know absolutely nothing about except it takes the fuel vapours and recirculates back to the fuel tank. VT can you explain?

:slap: Close, you mean the EGR 'Exhaust Gas Recirculation' valve. I cant be arsed to explain, Adam can do it better anyway...... :B_blite:

[phil]

didnt ask about cold start software, funny thing is it used to be fine and also only does it between being cold and warm