G13B Fast Idle help?

Hello all

The buggy has a fast idle of around 2,000rpm, I've searched the forum, the Wiki, and the wider internet too...

I keep finding references to :

Air Temperature Sensor (that has been replaced as it was showing incoming air temperature of 27 degrees)
PCV Valve
Idle Conrol Valve
EGR Valve
Cam Sensor
Crank Sensor

and others mention the spark plugs and coils...?

So, where to start? What's the mostly likely candidate for causing a high idle?

I also read on this old thread - www.bigjimny.com/index.php/forum/7-jimny...th-a-high-idle#68538 - that it could be "the thin rubber pipe from the inlet manifold to the vacuum control valves for the hubs is a likely culprit." - that worries me as I've removed all the vacuum hub gubbins, but I can't see a loose stray rubber pipe anywhere?... Would not having the vacuum hub pipes cause a high idle?
 

Don't know the G13B, so just throwing out some ideas.
Engine / coolant temperature sensor? If ECU controlled does it think it's cold.
If not ECU controlled - cold start bypass ( it's part of the Idle control valve). The potential give away is a coolant feed to the idle valve, a bimetallic strip within holds open the Idle valve until the engine is warm.
NOt sure if these apply, but they may.

Thanks Scimike... read on AusZookers about a potential airlock causing this too...?

Riccy (via WhatsApp) reckons start with the ide control 'valve', so I'll whip that out on Tuesday afternoon and give it a good clean...

Thanks... already replaced the air intake temperature sensor, as the MOT fella noticed the high idle (was effecting emissions) and hooked up an ODB panel and it was reading 27oC - so it looked like the ECU was trying to compensate by making the engine run faster, to try and cool it more...?

Interesting watch - 

 

Yes, I warned him it was an old format of ODB (I remembered reading it on this fine forum), so he went through four panels ending up with a dusty one from the bottom drawer of a SnapOn series of cabinets, but yes, in the end he established a link...

I'm sure I read you’d linked to an old one too?

 

One of these I got -

 

 
Fixed the fast idle today!

Started with the intake manifold...

 

It didn't look too bad?

 

But after a good clean quite a bit came off and onto the rag...

 

That's better! All around the intake, round the flap's edges, all round where it sits when closed...

 

And then the vacuum pipe left exposed after ripping all the vacuum free wheeling hub gubbins out...you can just about make it out in the yellow circle...

 

So some silicon hose with a self-tapper screwed into the end...

 

And wiggled into place to cap the escaping vacuum...

Reassemble everything, and then she...



Runs a lot better! 1,500rpm is a lot better than when it was running a little over 2,000rpm, I can live with that!

Thanks to Riccy for suggesting cleaning the intake manifold and idle control valve out, and to James for pointing out the exposed vacuum after taking the free wheel hub gubbins out! Where would we be without the amassed knowledge here on this fine forum