K 20 3/4 Ton Pickup 4WD V8-379 6.2L DSL VIN J FI (1983)
CROSS SECTION VIEW OF INJECTION PUMP
4.
Using a flashlight, look between the forward edge of the housing and the governor. The main shaft will be visible below the governor. Where
the main shaft enters the forward edge of the housing, a snap-ring should be visible. The use of a mirror may help to get a better view. Refer
to sketch.
5.
If the snap ring appears to be bent out of the shaft groove rearwards towards the governor, the ring must be replaced.
6.
To replace the snap ring, the injection pump must be removed and should be repaired at an authorized pump repair facility.
7.
If the ring is not bent, the rough idle is due to some other cause such as a fuel line air leak, timing, etc.
Technical Service Bulletin # 83T84VI
Date: 830901
Diesel Engine - Rough Idle Condition
Number:
83-T-84
Section:
VI
Date:
September, 1983
Subject:
6.2L DIESEL INJECTION
PUMP ROUGH IDLE - 1982-83 C/K/P/G TRUCKS WITH 6.2L DIESEL ENGINES
TO:
ALL CHEVROLET DEALERS
Some 1982-1983 trucks equipped with the 6.2L diesel
engine may
experience a rough idle condition. This condition may be caused by the injection pump main shaft snap ring.
If the snap ring is bent rearward, the governor arm can contact the ring causing a rough idle.
The snap ring may have been bent during initial pump assembly or can be bent during repair of the pump.
The snap ring is used to retain the drive shaft in the pump.
If a vehicle is received with a rough idle condition, the following procedure is recommended:
1.
Inquire as to the date of problem occurrence.
A.
If new, the snap ring may have been bent during initial pump assembly.
B.
If after pump removal/repair, the snap ring may have been bent during the repair.
C.
If neither A nor B, then a bent ring is not likely and this bulletin does not apply.
2.
If A or B above does apply and the condition is only a rough idle with smooth operation above 1,000 RPM, proceed to Step 3.
3.
Remove the injection pump housing cover. (Since the housing cover is full of fuel, use adequate absorption material around the pump.).
