Poor idle when cold

[Ady_ftta]

Hi all,

Forgive the low number of posts to the forum but I've read with interest and now got my car back on the road.

My car really struggles when cold. It will fire up straight away but stall within a few seconds. After re-starting it will tick over perfectly.

When I try to pull away the engine almost stalls - its ok once the revs have picked up, but as soon as they drop to near idle, the engine wants to stall again. Once the car is warm, everything is ok.

Is this normal for the GTO or is there something not right back there?

Any help would be very welcome.

[jdearden]

i think alot of 2.5 do this. i adjusted the throttle stop a lil bit a problem went away. i also let mine run up to temperture before driving away.

[Adrian W]

Maybe its a/the Lambda sensor

[SimonJW]

jdearden said:

i think alot of 2.5 do this. i adjusted the throttle stop a lil bit a problem went away. i also let mine run up to temperture before driving away.

+1

[R0162]

Nobles run very lumpy at low rpm with a faulty oxygen sensor and they are well known to go faulty, i replaced mine with bosch universal for £40 , worth a try and easy to do.
Alot of Nobles tend to get this problem that goes away when the car has warmed up it points towards the lamda sensors, but it could be also worth checking the plugs and make sure the air con is switched off at start as this can pull down the rpm, if you tweak the throttle position to increase tickover rpm the ecu should eventually remember the new throttle position and will adapt the mapping to adjust rpm back to what it was.
If problems persist get it plugged in for a diagnotics.

[2.5bluenob]

R0162 said:

, if you tweak the throttle position to increase tickover rpm the ecu should eventually remember the new throttle position and will adapt the mapping to adjust rpm back to what it was.
If problems persist get it plugged in for a diagnotics.

+ 1
The AA did this once for me to get me home as my car was stalling every time i dipped the clutch. But the next time i tried to start it the problem had returned . I take it that the ecu had ajusted itself.

[SimonJW]

Just to clarify my +1 was in support of the fact that my idle is particularly lumpy or inconsistent if it is started on an irregular basis. However, f started every day and used every one or two days there is no problem.

Simon

[Ady_ftta]

Thanks guys.

The car was recently serviced including new plugs so I presume these arent the cause.

I'll ask them to plug it in too see if the sensors are working. Its interesting the lambda sensors were mentioned as the car leaves a ring of soot on the floor from the exhaust when idling on the drive.

Does this reinforce the thinking about the sensors?

[Blu3R]

Ady_ftta said:

Its interesting the lambda sensors were mentioned as the car leaves a ring of soot on the floor from the exhaust when idling on the drive.

Off topic - but I have always been told that you shouldn't let a cold car idle and its better to drive off and put it under small amounts of load. Can't really explain why at the moment though

[jdearden]

mine always left soot on drive as is running too rich, this will be sorted when i finally get to see yellowshed. i think the main reason to let a noble warm up first is for the tubos to warm a bit same as letting it cool down. prolongs the life of the turbo's but i stand to be corrected