Grand Prix V8-350 5.7L DSL (1983)
Diesel MFI Pump: Testing and Inspection
Fig. 3 Fuel injection pump connections. 1982-83 V8 engine
Fig. 4 Fuel injection pump housing torque screw. 1982-83 V6 engine
1982-83
1.
Remove air crossover and install screened covers J-29657 (V6 engines) or J-26996-10 (V8 engines) or equivalent.
2.
Remove fuel return pressure tap plug or torque screw, Figs. 3 and 4. If equipped with torque screw, add second nut to locknut and back out screw
with nuts attached to avoid disturbing the adjustment.
3.
Install the seal from the pressure tap plug on the pressure tap adapter, tool J-28526, then install the adapter into pump housing.
4.
Connect a low pressure gauge to the adapter.
5.
Connect pickup tachometer, tool J-26925, to the engine.
6.
Check pressure with engine operating at 1000 RPM in Park. The pressure should be 8-12 psi with no more than a 2 psi fluctuation.
7.
If pressure reading is zero on 1982-83 models, check operation of housing pressure cold advance as follows:
a. Disconnect housing cold pressure advance electrical connector.
b. If pressure reading is still zero, remove injection pump cover and check operation of advance solenoid. Repair or replace as necessary.
c. If pressure is as specified with housing cold pressure advance electrical connector disconnected, check operation of temperature switch
located on cylinder head bolt.
8.
If pressure is still low, replace fuel return line connector assembly. If pressure is too high, fuel return system or HPAA may be restricted. Remove
return line at injection pump. Install fitting and short piece of hose to allow return flow to empty into a small container.
9.
If pressure is lower than before, correct restriction in fuel line.
10.
If pressure is still too high, replace fuel return line connector assembly. If assembly is replaced check injection pump timing and adjust if
necessary.
11.
If pressure remains too high, remove injection pump for repair.
12.
Remove tachometer, pressure gauge and adapter.
