Ninety-Eight FWD V6-260 4.3L DSL (1985)
Diesel MFI Pump: Testing and Inspection
Fig. 41 Roosa-Master pump pressure tap plug location
Fig. 42 CAV pump torque screw location
1982-83
1.
Remove air crossover and install screen covers J-29657 or other suitable covers.
2.
On Roosa-Master pumps, remove pressure tap plug. On CAV pumps, remove torque screw, Figs. 41 and 42. If equipped with torque screw, to
avoid disturbing adjustment add a second nut to lock nut, then back out screw with nuts attached.
3.
Attach low pressure gage to adapters.
4.
Connect magnetic pick-up tachometer.
5.
With gear shift lever in park position and parking brake on, check pressure with engine running at 1000 RPM. Pressure should be between 8-12 psi
with no more than 2 psi fluctuation.
6.
If pressure is at 0, check operation of housing pressure cold advance as follows:
a. Remove electrical connector from housing pressure cold advance terminal, Figs. 43 and 44. If pressure remains at 0, remove injection pump
cover and check operation of advance solenoid. If it is binding, repair or replace parts as necessary.
b. If pressure is as specified with housing cold pressure advance electrical connector disconnected, check operation of temperature switch
located in cylinder head bolt.
7.
If pressure is not within specifications, replace fuel return line connector assembly or check for restricted HPAA, if equipped.
8.
Remove tachometer, pressure gauge and adapter.
9.
Install a new pressure tap plug seal on pressure tap plug and install plug into pump housing.
10.
Remove screened covers and install air crossover.
