LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Jeep >> 1987 >> Comanche Base, 2.1 B >> Repair and Diagnosis >> Engine Performance >> System >> Fuel Injection System - Diesel >> Removal & Installation >> Injection Pump >> Installation
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Injection Pump: Installation

  1. Remove screw plug and copper washer from center of 4 high pressure outlets on rear of injection pump. See Fig 1. Install Dial Indicator Support (Mot. 856) in place of screw plug. Insert dial indicator into support. See Fig 1.
    Fig 1: Installing Dial Indicator
    G10572Courtesy of AMERICAN MOTORS/JEEP CORP.
  2. Position nut and lock nut on end of injection pump drive shaft. Lock the 2 nuts together. Loosen cold start throttle cable set screw. Move levers back slightly and rotate clevis pin 1/4 turn to disengage cold start system. See Fig 2.
    Fig 2: Disengaging Cold Start System
    G10573Courtesy of AMERICAN MOTORS/JEEP CORP.
  3. Rotate injection pump until piston is at BDC position (Dial indicator will stop moving at this point). Zero dial indicator.
    NOTE: With injection pump piston at BDC position, the pump shaft keyway should be positioned just before centerline of No. 1 fuel outlet fitting.
  4. Remove nut and lock nut from pump drive shaft. Insert key in pump shaft keyway. Install injection pump, leaving dial indicator in place. Ensure drive shaft key is aligned with keyway in sprocket. Loosely install pump retaining nuts.
  5. Install sprocket washer and retaining nut onto pump shaft. Tighten sprocket retaining nut. Remove sprocket holding plate. Rotate crankshaft 3 revolutions. Check timing belt tension. Adjust if necessary.
  6. Remove screw plug from TDC access hole in cylinder block, and install TDC Rod (Mot. 861). See Fig 3. Slowly rotate crankshaft clockwise, until TDC rod can be inserted into TDC hole in crankshaft counterweight.
    Fig 3: Inserting TDC Rod
    G10574Courtesy of AMERICAN MOTORS/JEEP CORP.
  7. With TDC rod in hole, dial indicator should read .031-.033 in. (.79-.84 mm). This reading represents the amount of pump piston lift. If reading is correct, go to step 10. If reading is incorrect, go to next step.
  8. To increase piston lift, rotate pump toward engine, and then slowly rotate pump away from engine until correct reading is obtained. To decrease piston lift, slowly rotate pump away from engine until correct reading is obtained.
  9. Remove TDC rod. Slowly rotate crankshaft clockwise 2 complete revolutions, and insert TDC rod in TDC hole in crankshaft counterweight. Dial indicator should read .031-.033 in. (.79-.84 mm). If reading is incorrect, repeat steps 8 and 9. If reading is correct, go to next step.
  10. Remove TDC rod from hole, and install screw plug. Remove dial indicator and support. Install copper washer and screw plug. Reconnect fuel pipes. Compress timing control lever and install clevis pin.
  11. Hold lever against clevis, and tighten set screw. Install and tighten injection pump rear bracket nuts. To complete installation, reverse removal procedure. The fuel return banjo nut is matched and calibrated to pump. If a new pump is installed, a new matched banjo nut must be used.
NOTE: DO NOT  reverse the 2 fuel line banjo nuts. The delivery line nut has two .1575" (4.0 mm) diameter holes, and the return line nut has a calibrated orifice.
scientia non olet · About LEMON Manuals