Engine rev hunting problem 2.0 16v

[davecupra16v]

Hi all,

I have a problem with my engine which is baffling me to high heavens. When it is idling it randomly hunts for revs, in no particular way or pattern. I have taken the following actions to try and fix the problem. Put my old air filter back on as I had an after market one on which did not have the intake sensor attached. Didn't work. Changed all the sparks plugs when it was fully serviced. Got a new dizzy cap on and replaced the rotor arm. Still no luck. It's now getting beyond my novice mechanical knowledge and would appreciate any suggestions from fellow cupra owners.

Cheers

DaveCupra16v

 

[andyj]

check all of the 4mm vacuum hoses, check that they are all connected properly and then also check the ends for splits... this can cause the erractic idle you're seeing

 

[lcjay]

could be the idel control valve

 

[Saul]

idle control valve and vac hoses, also check the breathers for blockages

 

[Fl@pper]

idle control valve and vac hoses, also check the breathers for blockages

gets my vote - sat at the front of the manifold area for both to check

also check throttle linkage for the micro-switch under it seen a few been loose or had wires repaired before now

 

[OllieL]

Mine is also doing this, but i do not have a clue how to check any of this. I thought it could be down to the middle box of my exhaust being shafted, as it only does it when its cold.
Anyone fancy telling/showing me how and where to check?? Very much appreciated

Ollie

 

[Fl@pper]

Mine is also doing this, as it only does it when its cold.

if its cold only the injection temp sensor might be duff ?

it gives ecu temp signal for when and how to apply cold starting fuel

replaces/run the choke effectively

bet your not old enough to remember choke cables / carbs / points

 

[lcjay]

as said it could also be the temp sensor.
the lamba probe or ecu can also give these problems but check all the cheap and easy bits first

 

[OllieL]

yeah i had some old polo's and my mate has a shed box metro at uni all of which with chokes and carbs!
Will change the exhaust at the weekend and give the throttle body a clean to see if thats an easy fix. If not then I will be back to pick your brains

Ollie