I have a 99 370 EC with 3116 cats. The port engine will notstart unless you use the emergence start switch. When I use it the engine turnsover maybe one time and cranks right up. Any thoughts. Batteries fully charged.
Check/clean battery and ground connections particularly on port engine.
Did you check ground connection on port engine?
- Oct 6, 2006
- 12,155
- Boat Info
- 1996 450DA
- Engines
- 3116 Caterpillars
There is a relay on Cat engines......on a '99 it is probably in a fairly large junction box at the rear of the engine but could be mounted separately at the rear end of the engine. The purpose of that relay is to save running heavy gauge wires from t he starter switch on the panel to the starter solenoid located on the engine at on top of the starter. The relay looks a lot like a Ford starter solenoid. Be sure to check the terminals on the relay and if they are good, tight and corrosion free, check the relay primary for 12VDC when the starter switch is depressed. No 12V, then the problem is at the dash/starter switch. If you have 12VDC at the relay primary, then check the relay secondary to be sure you have continuety when the starter switch is depressed and the primary activated.
This isn't rare but it is a simple system to diagnose because there are so few parts involved.
This isn't rare but it is a simple system to diagnose because there are so few parts involved.
- Oct 6, 2006
- 12,155
- Boat Info
- 1996 450DA
- Engines
- 3116 Caterpillars
That isn't the issue if the engine will crank but not start.
3116's are mechanical engines so they rely on cranking speed to develop enough compression to fire the combustion charge. Are you sure the port battery bank is fully charged and maintains enough voltage to spin the engine?
The only other part in the 3116 that may be the problem is the fuel supply solenoid on the back of the fuel pump.......but if the engine will start using the emergency start switch, then that pretty much rules out the fuel supply solenoid.
3116's are mechanical engines so they rely on cranking speed to develop enough compression to fire the combustion charge. Are you sure the port battery bank is fully charged and maintains enough voltage to spin the engine?
The only other part in the 3116 that may be the problem is the fuel supply solenoid on the back of the fuel pump.......but if the engine will start using the emergency start switch, then that pretty much rules out the fuel supply solenoid.
So,
The engine will "crank" but not "start" by normally pressing the Ign/Start switch?
The engine will "start" and "crank" by pressing the emergency start switch?
Very unusual situation you got there. First thing I would check is to make sure you have 12 volts positive on the fuel solenoid with the Ign/Start switch in the "run" position. The second thing is to make sure the voltage at the fuel solenoid remains above 10 volts when the engine is being turned over by the starter motor (cranking). If it goes below 10 volts the solenoid will not hold and will shut fuel off to the engine. Either bad port batteries or defective wire terminals will probably be the culprit.
The engine will "crank" but not "start" by normally pressing the Ign/Start switch?
The engine will "start" and "crank" by pressing the emergency start switch?
Very unusual situation you got there. First thing I would check is to make sure you have 12 volts positive on the fuel solenoid with the Ign/Start switch in the "run" position. The second thing is to make sure the voltage at the fuel solenoid remains above 10 volts when the engine is being turned over by the starter motor (cranking). If it goes below 10 volts the solenoid will not hold and will shut fuel off to the engine. Either bad port batteries or defective wire terminals will probably be the culprit.
