Ray70
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Hi guys, as many have probably noticed there seems to be an increasing number of threads with people dealing with stuck metering pumps and stuck fuel racks on their 802's and 803's
This seems to be a more frequent problem, now that virtually all available fuel sources have been low sulfur only for a couple years.
I just finished this repair on a pair of original 2010 super low hour ( 8hr. and 15hr. ) 803's I got recently.
Both were in pristine original condition and after initial inspection, found that 1 had 3 stuck metering pumps and the other had 1 pump that was just sticky enough to prevent the rack from springing open.
After the normal soaking and cleaning procedure, I installed the pumps in 1 machine with no issues, other than the typical rack alignment difficulty associated with having to remove all 4 pumps at once. As some folks know, removing all 4 allows the rack to move a little too far forward into the "Off" position, causing difficulty aligning the pin on the first metering pump you install. The 2nd machine gave me a little bit of difficulty, so I thought I'd share a few tips.
To install the 1st. pump if all 4 were removed you need to manually rotate the fuel shut off lever slightly clockwise, just off the stop screw to get the slot in the rack into the correct position under the cut-out in the block where the metering pump lever/pin aligns.
If you have difficulty, a small USB borescope camera will fit down the adjacent metering pump hole and allow you to see the pin and rack.
When trying to diagnose a stuck Rack / Pin an easy way to identify a stuck rack is to manually retract the solenoid. If the rack is free the fuel lever ( and black knob ) will automatically rotate clockwise and follow the solenoid arm as you retract the solenoid. If the lever stays all the way left against the stop screw then your rack and 1 or more pumps are stuck. NOTE: you will still be able to rotate the fuel lever clockwise by hand if the rack is frozen because it is spring loaded, but it will not freely rotate on its own within the slot of the solenoid arm.
When installing the metering pumps, be aware that the lever arm on the pump will interfere with the underside of the block until it is almost fully tightened down, this will cause the rack to be immobilized if any of the pumps are installed but not tightened down almost all the way.
Install 1 pump at a time and after each is complete, verify the rack is moving freely by either retracting the solenoid and watching the lever rotate clockwise, or put your finger into an open pump hole and feel that the rack is moving to the right when the solenoid is retracted.
Lastly, if you get 1 or more pumps installed successfully but just can not get the next pump's pin to align with the rack, try loosening the installed metering pump(s) and rotate them clockwise a little, moving the fuel inlet tube away from the adjacent pushrod tube. If this doesn't help, try loosening the jam nut on the fuel lever's stop screw and turn the stop screw in 2-3 turns and try installing the metering pumps again. If successful, put the stop screw back into its original position, tighten the jam nut, rotate all the metering pumps counterclockwise so the fuel lines are against the pushrod tubes and tighten them down.
This seems to be a more frequent problem, now that virtually all available fuel sources have been low sulfur only for a couple years.
I just finished this repair on a pair of original 2010 super low hour ( 8hr. and 15hr. ) 803's I got recently.
Both were in pristine original condition and after initial inspection, found that 1 had 3 stuck metering pumps and the other had 1 pump that was just sticky enough to prevent the rack from springing open.
After the normal soaking and cleaning procedure, I installed the pumps in 1 machine with no issues, other than the typical rack alignment difficulty associated with having to remove all 4 pumps at once. As some folks know, removing all 4 allows the rack to move a little too far forward into the "Off" position, causing difficulty aligning the pin on the first metering pump you install. The 2nd machine gave me a little bit of difficulty, so I thought I'd share a few tips.
To install the 1st. pump if all 4 were removed you need to manually rotate the fuel shut off lever slightly clockwise, just off the stop screw to get the slot in the rack into the correct position under the cut-out in the block where the metering pump lever/pin aligns.
If you have difficulty, a small USB borescope camera will fit down the adjacent metering pump hole and allow you to see the pin and rack.
When trying to diagnose a stuck Rack / Pin an easy way to identify a stuck rack is to manually retract the solenoid. If the rack is free the fuel lever ( and black knob ) will automatically rotate clockwise and follow the solenoid arm as you retract the solenoid. If the lever stays all the way left against the stop screw then your rack and 1 or more pumps are stuck. NOTE: you will still be able to rotate the fuel lever clockwise by hand if the rack is frozen because it is spring loaded, but it will not freely rotate on its own within the slot of the solenoid arm.
When installing the metering pumps, be aware that the lever arm on the pump will interfere with the underside of the block until it is almost fully tightened down, this will cause the rack to be immobilized if any of the pumps are installed but not tightened down almost all the way.
Install 1 pump at a time and after each is complete, verify the rack is moving freely by either retracting the solenoid and watching the lever rotate clockwise, or put your finger into an open pump hole and feel that the rack is moving to the right when the solenoid is retracted.
Lastly, if you get 1 or more pumps installed successfully but just can not get the next pump's pin to align with the rack, try loosening the installed metering pump(s) and rotate them clockwise a little, moving the fuel inlet tube away from the adjacent pushrod tube. If this doesn't help, try loosening the jam nut on the fuel lever's stop screw and turn the stop screw in 2-3 turns and try installing the metering pumps again. If successful, put the stop screw back into its original position, tighten the jam nut, rotate all the metering pumps counterclockwise so the fuel lines are against the pushrod tubes and tighten them down.
