[Engine] Very rough idling and hunting/hesitant when accelerating

[GSLondon]

Hi all

My 1.8 petrol X reg (year 2000) Berlingo is very rough on idle and hunts when accelerating.  Was working fine the day I bought it (but idle a bit rough).  Now much more noticeable.  

Always starts first time, and when cold it idles okay and doesn't really hunt, but seems to develop rough idling and hunting when accelerating once warm.  Have had the RAC out and there were no faults on the engine management.  He removed the MAF, the ICV and something else and the engine management registered faults for all three, which the RAC man said meant the engine management was working fine.  However, unplugging the ICV and plugging back in temporarily improved (5 minutes or so) the rough idling.  That said, no errors coming from any components.

Any idea what could be causing this problem?  Drove the car 45 miles last Saturday when I bought it and drove fine (albeit rough idling).  Any ideas?

Many thanksGS

[cancunia]

Perhaps a fueling problem? Maybe a filter or injector? Does it rev & stay at high rpm or hunt when you try to rev the engine while stationary in neutral?

[GSLondon]

Thanks for your reply. No, the opposite. It almost dies out with low regs at stationary and chugs for a couple of seconds when accelerating before picking up. Probably not explaining it well!

[Tree]

Idle control valve.


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[polar]

Idle control valve.


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That is what i was thinking Tree but idling okay when cold im not sure? I know the idle control valves are a common issue.

[GSLondon]

Thanks all. Should say that it still chugs when cold, but just not as noticeable. Will get an ICV and see if that solves.

[cancunia]

Please post how it goes with the ICV, would be interesting to know.

[Tree]

My old Ford Focus used to run perfect when cold but once warm would hunt on Tick over almost stalling. Once I swapped out the ICV problem was sorted. I can only think the ECU enriched the fuel when cold so it was less obvious.


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