Installation manual

90-898305

7-14

Incorrect Cam to Roller Setting

Throttle Position Sensor (TPS) Troubleshooting

If the throttle position sensor(s) are out of the intended operating range when

the engine is started, the Electronic Control Module (ECM) will sense that the

Throttle Position Sensor (TPS) has failed. The warning horn will sound, check

engine light will illuminate DDT will indicate failed TPS and the engine will go

into RPM reduction. When the engine is started, the throttle arm on the engine

must be against the throttle stop screw.

• Check throttle cable adjustment. The throttle stop screw on the throttle

arm must be against the throttle stop on the cylinder block when the

engine is started. Pre-load the throttle cable barrel 1 or 2 turns if

necessary.

• Verify driver is not pushing on throttle (if foot throttle is used) or activating

the throttle only on the control box.

• Check throttle cam to roller adjustment. If the roller is not down in the

pocket/valley area in the cam, there is a tendency for the roller to ride up

or down on the cam which causes the TPS link arm to push/pull on the

TPS lever resulting changing values.

• Make sure the roller doesn’t have any flat spots or is egg shaped if so

replace.

• Make sure the throttle link rod is not loose or have excessive play this

could result in false TPS voltage readings.

• Heat or pressure test the TPS.

Notes

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