900 L4-1985cc 2.0L DOHC (1986)
Boost Solenoid: Customer Interest
APC Solenoid - Chatters At Idle
FILE IN S.I. Man VOL. I
SEC. A-2 PG. 202
Service Information
SUBJECT:
CORRECTING APC SYSTEM INTERFERENCE ISSUE: 08/87-989
APPLICATION: 1986-87 900 TURBOS
Electrical interference at the knock detector wire and faults in the APC wiring harness can cause chattering of the APC solenoid at idle. This procedure
deals with correcting coaxial knock detector wire interference by taking the wire out of the engine wire harness and routing the wire by another way
within the engine compartment.
Before rerouting the coaxial knock detector wire, faults in the wiring circuit should be corrected, if necessary. Check the APC system ground points at
the left inner fender and at the radiator crossmember. The grounds must be tight and clean. The APC system transducer and vacuum switch should also
be checked for function. A failure in either one can cause solenoid chatter at idle.
Rerouting of the knock detector wire involves the replacement of the wire.
Knock Detector Wire
95-61-804
FIGURE 1 - REMOVING THE INSULATOR STRIP FROM THE APC CONTROL UNIT.
Knock Detector Wire Removal
1.
Disconnect the negative (-) battery lead and cover the terminal post on the battery.
2.
Remove the bracket for the APC system control unit from the fender and unplug the 25 pin connector.
3.
Remove the cover over the left headlight, rubber moulding from the right hand side of the intercooler, air mass meter and the left front turn signal
assembly.
4.
Disconnect the bottom hose from the AIC valve and the top hose from the throttle housing.
5.
Open the 25 pin connector and remove the rubber seal. Slide back the rubber, cut off the cable tie and pull out the connector block.
Remove both pin insulator strips. See Figure 1.
