Sluggish Starting Universal M30 Diesel Motor

[pvisich]

Last year my diesel started on the first crank. This year it takes two fairly long cranks before it starts. I normally hold the starter for 30 seconds. Today, I doubled the warm-up time (approx. 60 seconds), but still had to crank the motor twice before it started. After I run the motor for a while and turn it off, the motor starts on the first try. Is this potentially a glow plug issue? Thanks for your thoughts. Paul

[bottomscraper]

The Universal M30 is based on the Kubota D1101 or D1102 block.

I would first check if you are getting power to the glow plugs themselves. A multimeter set to DC Volts, measure the voltage at the terminal on the top of a glow plug (positive lead from meter, negative lead connected to ground/engine block) while having the key/preheat on. This should read about 10-13 volts). If it's low you might have a bad connection or have a bad relay, switch or solenoid. I don't have a M30 and my generic Kubota manual is really for tractors and other equipment and doesn't have details on how the preheat circuit is wired.

The glow plugs can be checked with a multimeter. No power is required, you may want to disconnect the battery before you do this for safety. You will need to remove the bar and wires connected to the top of the glow plugs. Using the meter set to test for resistance (ohms) on the lowest scale. Measure between the engine block and the top terminal of each glow plug. A good one will measure about 1.6 ohms. If it measures 0 it is shorted and needs to be replaced, if it measures much higher or infinity it is open and needs to be replaced. Luckily they aren't very expensive if you buy aftermarket parts.

[Frenchy]

It may be a good idea to activate the glow plug circuit with a solenoid, as wiring on this engine is not great. Here's an
excellent article by MaineSail detailing the deficiences of the wiring on these engines. The glow plug circuit is discussed
farther down. When I had my old M30, I followed all these recommendations. - Jean




https://marinehowto.com/universal-diese ... s-upgrade/

[pvisich]

Thanks for these tip and now wondering if I have some dangerous wiring in my boat based on the website you forwarded me. ~ Paul