Volvo TMD40A- rough starting, cause glow plugs?

[Labrador Coaster]

My recent boat has a low hour (800 hours) TMD40A VOLVO. She seems to struggle during start up, new starter, new batteries, I find it helps to pump the throttle while cranking. Thinking it might be faulty glow plugs, I removed and tested them, only one was faulty. Would only one cause this issue? I woulda thought that 5 cylinders would fire up quickly. But never used glow plugs before..

 

[colhel]

Air in the system? Crank the injectors and bleed the fuel pump if so.

 

[Labrador Coaster]

She runs fine once started. Would air stay in the system like that ??TKS.

 

[colhel]

Yes it can. I don't know the technicalities of why. Have you changed the fuel filter recently? Is it possible the pump and injectors weren't bled and cracked after?

 

[Labrador Coaster]

I haven’t touched the motor since I bought the boat, oil was fresh, new filters etc. I will keep that in mind when I launch her this spring, just had some new glow plugs so I will start with replacing the defective on to see if it makes a difference. Thanks for the advice, appreciated.

 

[alb40]

These engines should start up fairly easily with around 10 seconds of glow plugs, but they do like to have a few revs on (say 1200rpm) for a couple of minutes before they will idle smoothly. Try starting with the throttle set around halfway, and drop the revs back once it catches. If you try to start with the throttle on idle these engines won't go as they are old school indirect injection engines and need a bit of heat in the cylinders before they will run smooth.

 

[Labrador Coaster]

Your advice is spot on.. and is exactly what I have needed to do to get er going, happy to hear that it is normal for that particular motor. I compare it to the old 7000 hour 6414DF John Deere I have in my other boat, I touch the key, she barely turns over and she rumbles to life. I will change out the burnt glow plug, that should help a bit. Thank you for passing along your experience.