95WRX with Apexi FC
...usually runs fine but has generated a strange habit of juddernig at light throttle and below 2k rpm
...only does it when warm
the ignition is wandering between 17 degrees (as set) and 25 at idle when warm yet sits perfectly at 17 when cool (after droppping from fast idle)

curiously - and may or may not be linked - if I hold the throttle so the engine sits at approx 1400rpm in neutral, the engine will rhythmically rise and drop fro 1400 to 900rpm

in all other circumstances, teh engine is faultless
airflow is constant during the judder - so I dont think its the MAF

thoughts?

 

Hiya,

if the airflow volts are constant but you're seeing a change in load then the maf's not seeing what's going on.
You might want to give the intake, bcs plumbing and maf a good clean, - could just be a bit gunky, especially if you've still got the pcv and cam breathers still connected to the intake.
...good luck