elmouca
Active member
- Joined
- Oct 17, 2020
- Messages
- 32
I've been experiencing erratic engine speed under load on my LX565 with N844 engine. I finally figured it out but it took much longer than it should have. Below are my steps to help others trouble shoot.
1. Possible fuel / air delivery problem:
a. Replaced both fuel filters
b. Checked air filter and intake for obstruction
c. Added fuel pressure gauge to output of lift pump to monitor pressure during abnomaly
d. Inspected throttle linkage
2. Verify Governor Operation
a. Governor linkage internal to engine
b. Remove front engine cover with DIY puller to remove crankshaft pulley. There are some hidden retaining bolts on cover, so be mindful if it doesn't come off easily.
c. Inspect governor linkage
d. Some wear observed but not enough to validate syptoms - Replaced governor components despite no obvious cause
e. Re-assemble
f. Installed new oil seal for crankshaft with 3D printed seal driver.
g. Found Max Fuel Adjuster and Max RPM Adjuster to have been tampered with. Not field serviceable and must be replaced with sealed adjusters. Decided to reset both adjusters to the middle of the range instead of replacement.
h. Packed oil pump with assembly lube
i. Installed painted front engine cover. It is a bit tricky to align the oil pump into the pin in the engine cover.
No more erratic engine speed following repair. Unknown what was the root cause but the Max Fuel Adjuster and Max RPM adjust should not have been tampered with. If anyone needs the drawing for the puller or seal driver, please let me know.
1. Possible fuel / air delivery problem:
a. Replaced both fuel filters
b. Checked air filter and intake for obstruction
c. Added fuel pressure gauge to output of lift pump to monitor pressure during abnomaly
d. Inspected throttle linkage
2. Verify Governor Operation
a. Governor linkage internal to engine
b. Remove front engine cover with DIY puller to remove crankshaft pulley. There are some hidden retaining bolts on cover, so be mindful if it doesn't come off easily.
c. Inspect governor linkage
d. Some wear observed but not enough to validate syptoms - Replaced governor components despite no obvious cause
e. Re-assemble
f. Installed new oil seal for crankshaft with 3D printed seal driver.
g. Found Max Fuel Adjuster and Max RPM Adjuster to have been tampered with. Not field serviceable and must be replaced with sealed adjusters. Decided to reset both adjusters to the middle of the range instead of replacement.
h. Packed oil pump with assembly lube
i. Installed painted front engine cover. It is a bit tricky to align the oil pump into the pin in the engine cover.
No more erratic engine speed following repair. Unknown what was the root cause but the Max Fuel Adjuster and Max RPM adjust should not have been tampered with. If anyone needs the drawing for the puller or seal driver, please let me know.
