Technical chugging/spluttering when idleing cold

[bravo project]

hi guys
just wondering whether anyone could help with this one
when i turn my car over in the morning it idles around 1500rpm but then drops and the exhaust makes a sort of chugging/spluttering noise as tho its idleing low
once the car is warm shes fine
after driving the car for around 5 mins this stops and she drives like a dream...no faults.
iv heard about spluttering and chugging being linked to headgasket but i have no cream under oil cap, no over heating, no burning oil or water loss and no smoke on start up so surely it cannot be this :bang:

any advice or help appreciated as im out of ideas

 

[Adrian Bravo]

Hi
What engine do you have? Things like faulty lambda, temp sensors and throttle position sensors can cause this behaviour.

 

[bravo project]

cheers for the prompt reply
engines a 1.4 12v sx 1998
i was thinkin this was something to do with the exhaust as it is a little worse for wear
but as this only happens when cold i kinda ruled out a head gasket problem

 

[Stroke]

well shuldnt be lambda since it does it cold... trottle body. Just a guess... not a expert or ANYTHING

 

[Adrian Bravo]

1.4 will idle at 1300rpm until the engine is warm (detected through coolant temp, can take a while to warm up). Once warm the idle should hold steady at 850rpm

Ive recently had a lot of problems with over fueling and under fueling, idle dropping off, even stalling, sometimes loosing all power, exhaust was spluttery. I was getting an error code. The code said faulty Throttle Potentiometer.

Ive changed the throttle body and it seems ok but I need to drive it more to be certain. My problem was caused by the Throttle Potentiometer making the ECU choose the wrong fuel strategy.

And yes the lambda readings are not considered during cold start.

 

[bravo project]

cheers for the reply mate
whether this helps or not i dont know but i have a rather s*** induction kit on ( i know its childish but i love them) and was thinking maybe this was causing the ecu to adjust the fuel/air mixture incorrectly to compensate?

the kit will be coming off regardless of whether its causing the problem or not as i have just bought a new vroom vroom back box as the baffle has gone in the standard one.

 

[Adrian Bravo]

Maybe wait to see if you get anymore symptoms. They do stay in cold start for quite a while. Have you had the 1.4 for long?

 

[bravo project]

since around feb 09
not had this problem before so was thinkin it maybe the induction kit

can i just ask aswell, my indicator stalk isnt working
it clicks in place and clicks off when i turn but indicators arent flashing, also the hazard lights button wont work the hazards either
tried replacing for a scrap stalk and no joy
was wondering whether it maybe the unit that the indicator sits in?

cheers for the reply

 

[Stroke]

well... i guess whatever is makeing it overfuel (i think that it does), it does adjust it when lambda kicks in (i think ) since then he can correct on the o2 out going "air".