1.9gti idles at 1400rpm

[Tootall 0]

Hi all,

 

My 1.9gti only likes to idle at 1400rpm and won't cause me any issues, but if i set it any lower than that the car starts to rev up and down until it drops to low and cuts out. Whilst driving it will be jerky, bouncing idle and really poor fuel efficiency. Upon starting I'll have to give it extra revs until it settles so it doesn't cut out. 

I know these should sit at around 900rpm roughly but mine just won't.

Any ideas please?

Anyone is Suffolk who could have a look to see if it's set up correctly?

 

Cheers in advance.

Edited October 11 by Tootall
Extra information

[stewal 8]

Issues like these are usually air leaks from the numerous pipework and joints on the intake side.

 

One that's easily forgotten is the vacuum advance to the distributer: if the diaphragm splits in the distributer it will let unmetered air in and also, no working vacuum advance will increase fuel consumption and give a jerky drive.

[Tootall 0]

10 hours ago, stewal said:

Issues like these are usually air leaks from the numerous pipework and joints on the intake side.

 

One that's easily forgotten is the vacuum advance to the distributer: if the diaphragm splits in the distributer it will let unmetered air in and also, no working vacuum advance will increase fuel consumption and give a jerky drive.

Thanks pal I'll check it out, it's had a new dizzy and leads this year.

[welshpug 1,661]

If you fancy having a crack yourself then your best starting point is to get a Haynes workshop manual, a multimeter and a decent set of basic tools.

 

(emphasis on workshop, not the service and repair manual, only available used, get the later print variant as the wiring diagrams are easier to decipher)

 

Check it has all the correct matching fuel and ignition components, and that you know what system it has, look at the ECU to see if it's Jetronic or Motronic.

 

If its had a dizzy it's likely to be Jetronic, and the part number typically ends in 066 on those dizzys,  afm would be a 109.

 

Start with checking for air leaks, sad pipes, oil filler pot mounting bolt on the side of the Intake manifold.

 

Check the throttle basic settings, check the resistance on the blue coolant temperature sender, then you can move to the ignition timing,    personally I do this manually on a test drive but you need a reasonable grade hill to load it up and check for pinking, advance till the idle just raises then back off a touch, if it doesn't pink you are good.

 

 

AFM I would leave till you have it at a garage with an emissions analyzer, the limit for non cat vehicles is 3.5%, these run best around 1.5%.

Edited October 13 by welshpug