Injector compression check

[pvid08]

I have a volvo tmd31 in my 20ft cuddy with about 1600 hrs.
I would like to get the compression checked on the injectors. I have some questions. Do I remove the injectors and bring them to a injection service shop? What is involved in removing them? Approximately how much should it cost to have them checked and adjusted if neccessary (or possible). How much to replace them?
Any feedback would be appreciated.

Pvid08

[Brian]

I have never heard of a compression check on the injectors. You can have the injectors rebuilt, and they will check the spray pattern and the pressure at which they open. I'm not sure if your 31 has a similar injector set up to a 41 P that I had in another boat, but if it is - you will have to loosen the nut holding down the injectors and then hope they are loose enough to come out of the copper sleeve that is pressed into the head. If they have never been removed - it is possible you could disturb the copper sleeve since there is probably a heavy carbon buildup between the injector and the sleeve, and the o rings that seal it (coolant runs around it within the head) so you have to be careful. if you attempt to remove the injector and also remove the copper sleeve - you are going to have to remove the head in order to make sure the new copper sleeve is correctly installed and doesn;t leak. Volvo sells a tool to remove the injectors (what else is new) but I never needed it to remove the ones in the 41 P.

[Mistress]

yes, you have to remove them and have them bench tested to check pop-off pressure. Why do you feel you need to do that though? This is usully done just on rebuilt or hot-rodded injectors.

I don't know how to remove volvo injectors. The Cummins is pretty easy.

I'd suggest a decent service manual and/or www.boatdiesel.com

[pvid08]

Thanks for the info.

I had trouble strating the engine in the cold when I winterized at the end of last season. I was told it may be due to not enough compression in the injectors. That's why I am looking into it.

www.boatdiesel is a good site. My membership expired.
Just wanted some insight from members on this board.

Peter

[skipm]

I think you mean pressure test.Most diesel shops can do it.Get the factory shop book.

[Mistress]

Do you have glow plugs? That's a more likely problem of hard cold starting.

[pvid08]

Thanks for the feedback.
I finally had a chance to work on it. I looks like the problem was air in the fuel line. When I changed the fuel filter at the end of the season I probably didn't bleed all the air out properly, which was preventing the injectors from getting enough fuel, and eventually couldn't start the engine.
I loosened the bleeder screw on the fuel pump, pumped the primer, and also loosened the injectors to get all the air out.
After that it was starting and running fine.
I was able to out for a late afternoon run on Memorial Day.

Peter