borrow someones AFM and test it. mate had a problem like this in his 34. he soldered all the joints in the AFM again and it went sweet as. was good when cold but when it warmed up it spat the dummy. but at all diff times. depending on how much of a hard time he gave it. once he did that never had trouble since. best way i think is get it warn and take the plug off the AFM and see what it does. when its dissconnected it should blow black smoke and be runnin rough or stop.