1.4 runs perfect on idle for 12 seconds then starts hunting rough idle and stalls

[red chilli]

first off hello all great site !

i own a seat ibiza chill 1.4 mpi 97 reg 5dr now when i bought this car it had a blown headgasket
so i got the head checked all a ok ,,, then changed headgasket and timing belt and tensioner oil air and fuel filter and plugs ,it ran when headgasket was blown but only for 12 seconds then would idle really bad and stall,

ive changed all above allthough its running better it still has the same fault ie from cold it runs perfect on idle for 12 seconds then starts hunting rough idle and stalls ,

ive changed ptu o2 sensor 2nd hnd , leads plugs dizzy cap rotor arm, throttle body ,cam sensor injectors , all to no avail ,

only thing to add is it drives ok if you keep revs up but just wont idle on its own,,after first start 12 seconds , even ran it up to temprature no difference, any ideas ??? thanks for any help in advance cheers paul




ive got a spare engine on standbywith allrunning gear inc gearbox ,but its all up fpr grabs as its not the same engine as the one in my seat its from a 3door ,ps im in croydon surrey

 

[ibiza95]

im not to sure if it is right but try cleaning your throttle body as i read somewhere about someone had a similar problem and was sorted by cleaning the throttle body

 

[red chilli]

cheers , i did try this didnt make any improvement .i even switched it over with another it ran worse ,,thanks for idea though .

when i cleaned it up though i just cleaned what i could see on it and underneath it once removed , hope thats right .

when its running bad you can see the throtlle working its opening to add more revs

 

[Cupra Kid]

Check the fuel filter and pump, if its 12 seconds and then trouble could be a lack of constant pressure from the tank

 

[red chilli]

cheers makes sense ive changed the actual filter allready , but fuel pump is worth a go , cheers paul .

just to add it will only run fine for 12 seconds from cold

every time i restart the car this good running time decreases ,, if its any help

ie 12 seconds only from cold after that it takes about2 seconds max ..cheers paul,

 

[red chilli]

still no good but....i made an improvement in this heat over last 3 days ,

for some reason the car will now idle on its own , but its stil erratic ,, around 900 rpm-1100 , up n down in same time as before but a lot more settled than it was ,

all i did was set the idle via throttle cable to 1500 revs ,for a long while as i was setting up some amps for dans car,,

know when revs were held at 1500 rpm it didnt drop at all , when i returned throttle to its original postition , it held without stalling ,the more i reved it the better it got , it was as if the ecu kept resetting its self , ,, i say this as on my old car if you reset it the revs would go up n down untill it settled down to normal idle ,

bearing in mind the car was up to tempreature , i shall try today and see if its still ok , anyideas ?

 

[red chilli]

carb cleaner made a huge difference , runs a lot better , cheers guys