New IAC - surging RPM when stopping?

[walla24]

Hi guys
If you can figure it out I'll donate to a charity of your choosing!

So:
Transit Connect 2005
1.8L petrol/LPG

Engine idle very low when cold and stalled at junctions- Previous owner cut IAC connection! I replaced the IAC and rewired (couldn't tell the polarity but issue below happens when plugged either way).

Engine idles high - 12-1400rpm
When driving if you put the clutch in the revs climb slightly then fall and settle at 2000rpm.
As you come to a stop (clutch in) at 5mph the revs suddenly shoot up to 3-3500rpm and only fall to idle after 10 seconds of being stationary.
No codes when plugged in. All self tests complete without issue including IAC self test which raises idle as it should.

Possible causes:
-IAC wiring issue? If I leave the IAC unplugged the engine drives fine without issue but idles slightly high. IAC self test raises idle and releases as it should.
-PCM sending wrong signal to IAC?
-EGR vacuum solenoid had a slight perforation to the diaphragm but issue remains after repair.
-MAF issue? Symptoms remain the same without the MAF plugged in (so not MAF issue?)
-Previous owner - could he have somehow set the idle higher to counteract cutting the IAC wiring? and now it struggles to close throttle body?
-Throttle body very clean, sensor attached.
Just had cam belt kit done- engine mount removed and engine moved up/down to fit - possible damaged connection?

No idea is a bad idea!

[walla24]

It's not the MAF!
Just put a new one on, made it rev even higher when it surges! balls

[walla24]

SOLVED

previous owner snipped faulty IAC cables AND improvised a bodge to hold the throttle body open slightly at idle to counteract!
Air sneaking in from this + when now working IAC kicked in meant loads of air in causing a surge of RPM

All sorted and super smooth idle at about 800, perfect!

finally can relax been poking around for days, cheers