Airbox popping noise/ idle misfire but fine when driving!

Bought myself a puma as a project, it has an issue with the idle, when driving up and down the road it seems fine, however when idle its making a popping noise through the airbox and the exhaust, the issue has all the symptoms of a slight misfire, i know the rocker gasket is leaking a fair bit so there may be oil on the plugs, i have not collected the car yet so cannot remove cam cover etc.
My question is, has anyone encountered this before?
I have done a little bit of homework and it seems people often find the throttle position sensor to be at fault and also the maf and potentially the coil pack.
I have my doubts about the coil pack as it drives ok up and down the road.
It has a new idle control valve.
Could it be some of the 16 valves sticking?!

Sounds like a MAF issue; check it is plugged properly and connections are clean.
Also do you know when the last time the plugs were changed? Might be worth taking one out to check the condition.
Could also be lambda sensor...sorry very vague reply :grin:
Alex

is there a way to test for these issues? i heard it could be a valve sticking and to take the plugs out and put some redex petrol cleaner in there for 30 mins then start up and a ploom of smoke and valve is possibly fixed

Picked up the car today and when driving on th motorway it drives fine and pulls extremely well, the issue is not any lambda sensor as i unplugged them whilst engine was running, also i changed the idle control valve and the throttle position sensor, no difference, i put hydraulic valve cleaner in it before driving home, no difference. The idle is just jumpy and the engine makes a strange grinding noise similar to abs noise at about 1700rpm.
The plugs are new, only thing to try now is coil pack.
There is no cream in the oil.

I have tried new coil pack and plugs and leads and tps and idle control valve also checked every wire, idle is still lumpy, anyone got any ideas? I have also checked the vacuum hoses

Also removed pas connector, no difference.
2 questions- could it be the vct? I.e the solenoid?
There is a strange grindy noise at 1700-2000rpm sometimes as if the cambelt tensioner is dying? Its coming from that area, could that possibly make the belt jump and put the timing out?

The solution to this was cylinder number 3 has bent valves die to cambelt slipping from a tensioner on its way out!
Need a new head or new valves on cylinder 3!