idle POSS, RR

[rwaterman]

Every now and then when sitting in traffic my car has been idling a bit strangly. Normally when warm it ticks over at about 900 which i understand to be normal but the last couple of weeks only sometimes has the revs been repeatably rising and dropping as if i was revving the engine, then when i drive off it goes back to normal. This has happened a few to many times now and a friend has suggested i get it on the rolling road for a tune, as this apparently happened to his new vts he just took it back to citreon and they re-tuned it for him. Does it sound like it just needs a tune? Aswell, on my way home from work just then it was on 1100rpm on tickover then dropped and rose higher again what is going on?? No mods at all on my car....

ROB.

 

[Matbrown]

Could be a dodgy throttle potentiometer!

The red thing next to the airfilter.



Mat.

 

[JamesG]

check the earth wire thats goes to the gearbox

 

[Will16V]

Mine does something similar, just since the weather changed tho when it got a bit colder. Start up in the morn, ok....driving to work in traffic, stopping and starting etc....idle goes from 900 to about 650, rev engine, goes up then back down to 650....if i leave it running, it wont stall, just slowly rises back up to 900 after a few secs...

 

[Bryan]

could also be a carbon deposit build up in the inlet manifold, this is what happened to my uno tb - just take the car into any decent garage, and they should be able to diagnose the problem

 

[rwaterman]

Willy16v yeah thats what mine does anyway from cold thats not the problem though its when its warmed up and im sitting on idle and the revs will be on 900 then will rise to 1200 then back down again it just keeps moving up and down.................