CHECK ENGINE IDLE SPEED AND MAXIMUM SPEED
Tech Tips
For more information about the intelligent tester, refer to its operator's manual.
If an intelligent tester is not available, use a tachometer's tester probe as a substitute.
Connect the intelligent tester to the DLC3.
| *a | Front view of DLC3 |
If a tester is not available, connect the tester probe of a tachometer to terminal 9 (TAC) of the DLC3 with SST.
Inspect the idle speed.
Tech Tips
Make sure that the engine is warmed up.
Make sure that the A/C switch is off.
w/ DPF:
Make sure that PM regeneration is not being performed.
Start the engine and measure the idle speed.
| Idle Speed | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
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Inspect the maximum speed.
Start the engine.
Fully depress the accelerator pedal.
Measure the maximum speed.
| Maximum Speed | ||||||
|---|---|---|---|---|---|---|
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If the tester probe of a tachometer is connected to the DLC3, disconnect the tester probe together with SST from terminal 9 of the DLC3.
Disconnect the intelligent tester from the DLC3.
INSPECT CYLINDER COMPRESSION PRESSURE
Tech Tips
Measure the compression pressure if the engine power is insufficient, oil is consumed excessively and/or fuel economy is poor.
w/ DPF:
Remove the 4 glow plugs Click here.
w/o DPF:
Remove the 4 glow plugs Click here.
Disconnect the 4 injector connectors.
Crank the engine to expel soot and other foreign matter from the inside of the cylinder.
| *1 | SST (Compression Gauge) |
| *2 | SST (Attachment) |
Measure the compression pressure.
Install SST (attachment) to the glow plug hole.
Connect SST (compression gauge) to SST (attachment).
Measure the compression pressure while cranking the engine.
Tech Tips
Always use a fully charged battery to obtain an engine speed of 250 rpm or more.
Perform the procedure above for each cylinder.
| Standard compression pressure |
|---|
| 2700 kPa (27.5 kgf/cm2, 391 psi) or higher |
| Minimum pressure |
|---|
| 2200 kPa (22.5 kgf/cm2, 320 psi) |
| Standard difference between each cylinder |
|---|
| 500 kPa (5.0 kgf/cm2, 71 psi) or less |
Note
This measurement must be done in as short a time as possible.
If the compression in one or more cylinders is low, add a small amount of engine oil into the glow plug hole. Then, repeat the procedure above for the low-compression cylinder(s).
Tech Tips
If poor compression improves after adding engine oil, the piston rings and/or cylinder bore may be worn or damaged.
If the pressure remains low, a valve may be stuck or seated improperly, or pressure may be dropping due to leakage through the gasket.
Remove SST (attachment and compression gauge).
Connect the 4 injector connectors.
w/ DPF:
Install the 4 glow plugs Click here.
w/o DPF:
Install the 4 glow plugs Click here.