TM 9-2815-225-34&P 3-63. FUEL PUMP TESTING AND CALIBRATION (Contd) LOCATION/ITEM ACTION REMARKS c.  Mounting Fuel Pump to Test Stand (Contd) 31. Governor spring pack b.  Install fuel pump idle Use fuel pump idle adjusting tool housing (43) (Contd) adjusting tool (90) on governor (3375981).  To assure that gover- spring pack housing (43). nor has enough clearance to cut off during calibration adjustments, carefully pull tool shaft out so that snapring is lightly resting against stop.  If too much force is put on tool, snapring may be pushed off tool shaft and down into fuel pump main housing (51). 32. AFC cover plate (42) and Remove from fuel pump main AFC adjusting tool is part of AFC restrictor (41) housing (51) and replace with fuel pump adjusting tool kit AFC adjusting tool (91). (3375189).  Pull out knobs on tool to disengage sockets.  Relief cuts on tool must face toward rear of pump to allow clearance for AFC fuel passage pipe plug (92). 33. Regulated shop air source Connect to test stand (1). Maximum pressure should not exceed 40 psi (275 kPa). 34. Aneroid AFC adjusting line Connect to AFC adjusting tool (91). (93) NOTE Some Big Cam I engines may have fuel pumps having the Air Signal Attenuator (ASA).  For those pumps, perform step 35.  Big Cam III engine fuel pumps do not require step 35 to be performed. 35. Air Signal Attenuator (ASA) a.  Calibrate the fuel pump Smoke control valve produces a and restrictor.  (The ASA and without the smoke control valve. delay in intake manifold restrictor are collectively Valve is threaded into AFC cover pressure signal to the AFC, called the smoke control plate (42).  See illustration on next resulting in a reduction of valve.) page. accelerated smoke. CAUTION When  removing  the  ASA  from  the  AFC  cover  plate,  do  not  disassemble  by  placing  the wrench  on  top  of  the  ASA.    Place  the  wrench  on  the  hex  at  the  bottom  of  the  ASA,  just above the top of the restrictor for disassembly. b.  Check valve by blowing There should be free air flow when through each side of valve. blowing through the 1/8-NPT end of valve (AFC cover plate end) and restricted flow when blowing through intake manifold end (almost no air flow). c.  Check restrictor check ball for Check ball is located in the sticking by shaking it and restrictor (41) to prevent a reverse listening for check ball to rattle fuel flow to the intake manifold if in restrictor (41).  If check ball is AFC bellows ruptures. stuck and not moving when restrictor is shaken, replace the unit. d.  Check restrictor orifice by If no air bubbles are coming out connecting it to an air line. of orifice, restrictor (41) is plugged Immerse restrictor (41) in clean or contaminated and should be test fluid and pressurize it with replaced. 3-476