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Daniel Wilson
Daniel Wilson,
Category: Medium and Heavy Trucks
Satisfied Customers: 5161
Experience:  Owner at DJ Wilson
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I have a 99 Mack Model RD6906 engine EM7 truck will start

Customer Question

I have a 99 Mack Model RD6906 engine EM7 truck will start tack will not work and only runs 3-4 seconds
Submitted: 1 year ago.
Category: Medium and Heavy Trucks
Expert:  Daniel Wilson replied 1 year ago.

Hi David, My name is***** will be glad to help. Is the malfunction engine light on?

Expert:  Daniel Wilson replied 1 year ago.

What codes are you getting?

Customer: replied 1 year ago.
The malfunction light is not on and no codes
Expert:  Daniel Wilson replied 1 year ago.

I see you replaces the speed sensors already. Check the harness and connector pins to be sure the ECM is actually getting the speed signal. You should have 5 V to the sensor and the ECM reads the return voltage

Expert:  Daniel Wilson replied 1 year ago.

Check the fuel lines between the tank and pump for leaks or restrictions sucking air. will it fire on silicone spray or ether?

Expert:  Daniel Wilson replied 1 year ago.

Install a clear hose or site glass to check for air bubbles. If low fuel supply pressure you could have a faulty fuel transfer pump

Expert:  Daniel Wilson replied 1 year ago.

Low coolant will shut it down but would throw a code usually for shutdown

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