QuestionI have a 1995, GMAC pick up truck with a 6.5L diesel engine. I need to change the fuel injection pump. Can you please give me step by step directions about how to remove the old one and install a new injection pump? Also, I have been told that there have been modifications made to this pump due to problems encountered with the original ones. If this is so, will the new pump automatically come with these modifications? Thank you.
Paul
AnswerLet me start by saying, I am not a diesel technician and I have never replaced an injection pump. I can however supply you with the service literature. I do know that there are special tools required to service those pumps and that there is a timing procedure which you require a scan tool to complete. As for modifications, again, I appologize but I cannot answer that question with any certainty.
Hope this helps you.
Fuel Injection Pump Replacement
Removal Procedure
Tools Required
J 41089 Injection Pump Wrench
Caution: Unless directed otherwise, the ignition and start switch must be in the OFF or LOCK position, and all electrical loads must be OFF before servicing any electrical component. Disconnect the negative battery cable to prevent an electrical spark should a tool or equipment come in contact with an exposed electrical terminal. Failure to follow these precautions may result in personal injury and/or damage to the vehicle or its components.
Remove the negative battery cables.
Remove the intake manifold.
Remove the injection lines.
Remove the fuel inlet line from the injection pump.
Remove all necessary harness connectors and hoses from the injection pump.
Remove the fuel return line at the top of the injection pump.
Remove the oil fill tube.
Remove the grommet for the oil filler tube.
Manually rotate the engine to gain access to the bolts (1) that hold the driven gear to the injection pump. Access is gained through the oil filler neck hole.
Remove the driven gear bolts.
Important : Never engage the starter motor to rotate the engine when the injection pump is removed as severe engine damage will occur. With the injection pump removed the pump driven gear could jam in the front housing by engaging the starter motor, resulting in a sheared crankshaft or camshaft gear key and possible valve train damage. Always bar the engine over by hand to avoid internal engine damage.
Remove the injection pump flange nuts. Use the J 41089 injection pump wrench.
Remove the injection pump.
Cap all open lines and nozzles.
Remove the flange gasket.
Installation Procedure
Install the new flange gasket on the injection pump .
Adjust the locating stud (1) to the proper position to match with the slotted/elongated hole in the driven gear.
Important: Be sure the locating stud (1) on the injection pump hub goes into the slotted/elongated hole in the driven gear.
Install the injection pump making sure the locating stud is positioned within the slotted/elongated hole (1) in the driven gear.
Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.
Install the injection pump flange nuts.
Tighten
Tighten nuts to 40 N·m (30 lb ft).
Important: All the driven gear bolts should not be torqued until all the bolts are installed. This will allow for the proper alignment of all the bolt holes.
Install the driven gear bolts (1).
Tighten
Tighten the bolts to 25 N·m (18 lb ft).
Install the grommet for the oil filler tube.
Install the oil filler tube.
Install the fuel feed line at the injection pump.
Install the fuel return line to the top of the injection pump.
Install all necessary harnesses and connectors.
Install the injection lines.
Install the intake manifold.
Install the negative battery cables.
Adjust the injection timing.
