Rough/low idle when warm

[db98]

My 1.6 16v RSi is idling rough and quite low once the engine has warmed up, on cold start the idle sits just under 1k and runs smoothly then once it’s warmed up the idle drops below 500 and is quite rough to where you can feel the engine shaking a bit. I’m guessing it could either be plugs/coils, lambda sensor or another sensor (possibly map sensor or tdc?). The car drives fine with no hesitation however it seems to be getting slightly lower mpg than usual. Can anyone point me in the right direction of where to start diagnosing this issue before I start throwing parts at it? Thanks in advance.

 

[Chocice]

I would start with the easy stuff take your spark plugs out and check them, check your battery and alternator if it’s just started recently as the cold weather puts a strain on the electrics, check the thermostat isn’t stuck open causing the engine to stay cold, then move onto the bits you mentioned. I would buy parts as cheap as you can from eBay etc. if you are guessing what could be wrong, there are some absolute bargains for old clio bits it might not cost you as much as you think to renew a few bits.

 

[SharpyClio]

Are you getting an EML?

Injectors would normally throw a code, but could be anything from a long list.

If no codes then start with the cheap stuff, plugs, leads, coil pack.

If no better I would look at cleaning the TDC sensor and making sure the MAP sensor is in correctly.

Then I'd look at injectors, you can test the resistance, doesn't always give a clear view but you want 14ohms across them.

Go through a process, don't replace more than one thing at a time as you will never know what it was if you replace loads of stuff at once.

 

[Chocice]

This video goes through what u should be doing but I would go with the fix and work back.