n1cky(cf23)

any help if possible my mk1 focus idles ruff likes its got an air leak, check all pipes inlet manifld an throttle housing but no sign. also running rely weak and pinks under heavy accelration

marky_g

get it into an a mechanuic mate diagnosit machine will find your faults

tabetha

Clean the MAF first with carb cleaner, give it a good dosing, then shake dry, then reset the KAM fuse in the fusebox, it is a 2 amp violet colour fuse, this will make the ecu relearn it's best setting, so will be a little lumpy to start with but after around 5 miles of mixed driving should be fine.
Another thing to check is the dreaded "T" piece of rubber, this is near the rear nearside corner of the head underneath all the gubbins, and connects the PCV valve at the front into the inlet manifold, these split and leak air, the pcv valve can also jam, just squeeze the hose shut with pliers to test.
tabetha