Evening all, soon time to put in my 1.2 16v cinq for an mot but have an emissions issue and reckon a problem on hot idle is what's causing it (or at least a symptom of it).
From cold, it idles beautifully. It's silky smooth. As it gets hotter and the idle revs dip, that's when problems start to show, the revs drop to about 875rpm fine but every so often they will try to drop down/stall attempt but it gives a small pop in the exhaust like an overfuel stutter and the revs rise back up to around 875 rpm. Given there was an overfuel in the emissions last time i figure it's connected.
Any idea of likely causes?
Given it seems to be temperature related, i changed the blue coolant temp sensor for a known good one but that didn't work. Map sensor seems to be working fine from what i can tell given it runs horrible without and pretty much tries to stall, then when you reconnect it running, it sometimes does.
Today took the throttle body off and my idle control valve seemed a bit gummed, so cleaned it up thinking it was perhaps sticky so slow to react, seemed to free it off and when i started it with the valve opened, it took 4 or 5 start attempts for it to adjust and re-set itself without revving it's nuts off at idle, so possibly still sticky and not reacting to any changes when it's up to temp?
From cold, it idles beautifully. It's silky smooth. As it gets hotter and the idle revs dip, that's when problems start to show, the revs drop to about 875rpm fine but every so often they will try to drop down/stall attempt but it gives a small pop in the exhaust like an overfuel stutter and the revs rise back up to around 875 rpm. Given there was an overfuel in the emissions last time i figure it's connected.
Any idea of likely causes?
Given it seems to be temperature related, i changed the blue coolant temp sensor for a known good one but that didn't work. Map sensor seems to be working fine from what i can tell given it runs horrible without and pretty much tries to stall, then when you reconnect it running, it sometimes does.
Today took the throttle body off and my idle control valve seemed a bit gummed, so cleaned it up thinking it was perhaps sticky so slow to react, seemed to free it off and when i started it with the valve opened, it took 4 or 5 start attempts for it to adjust and re-set itself without revving it's nuts off at idle, so possibly still sticky and not reacting to any changes when it's up to temp?