MD7a Injector Question

[RichardTaylor]

I have just had my injectors serviced, and the guy mentioned there may be some copper washers at the bottom of the injector hole.

Is this the case with the MD7a?

If so what is the likelihood of replacing the injectors using the existing washers?

Any other comments or hints?

I was told to use copperslip grease on the injectors to aid fitting and removal at a later date.

TIA
Richard

 

[john_morris_uk]

The MD7 does NOT have a copper washer between the injector and the bottom of the 'injector hole'.

I have checked the workshop manual and there is a copper sleeve with an o ring in the head which needs a special tool to remove and replace.

When we had the injectors serviced on an MD7A that we had on a previous boat, the diesel engine shop supplied new washers with the serviced injectors. No wonder it never ran properly ever again.

Copy of the workshop manual available at http://www.bluemoment.com/manuals/Volvo_MD6A_MD7A_Workshop.pdf

 

[RobinA]

I was told by the injector specialists that they should not have a copper washer. In fact, one of mine did and they removed the washer and polished the mating face on the injector.

It was also suggested to me by a friend to use copper grease. I did not use grease for no particular reason other than I didn't have any and the manual made no mention of it. My engine is now running fine, but I guess I may have another battle removing the injectors next time.

Out of interest, what did they do in servicing your injectors and how much did they charge? Mine were put on the test jig - the spray pattern looked OK, with no drips. However he then demonstrated a brand new injector which appeared to pulse whereas mine had a continuous spray. The specialists conclusion was that mine would be less fuel efficient but last me another couple of seasons. As I generally only use 20 gals in a season, efficiency was not such a priority - so I'm soldiering on until they really need replacing. I guess it must be slighly smokier than if I replaced them, but it doesn't seem too bad.

 

[john_morris_uk]

They charged a few pouinds to test and put right. Not sure about 'pulsed' pattern. Never heard of it, but I am only an amateur diesel engineer. Perhaps someone else will know?

 

[Parsonsheath]

Why did you get them serviced, what was the problem before, and what difference did the service make?

 

[RichardTaylor]

Since owning the boat our engine has always been smokey, but our first outing this year we were more like a smoke flare /forums/images/graemlins/blush.gif

All advice points towards the injectors needing servicing (smoke smelt of diesel fuel, suggesting unburnt fuel), so out they came

Panda Diesel Fareham serviced them at a cost of £38.00 for the pair. New Nozzles were not required otherwise we would have been in for about double that.

 

[john_morris_uk]

The problem was unreliable starting. We got them serviced at Plymouth Diesels and it didn't change much at all! We swapped the engine for a Nanni the next season.

 

[Frankklose]

The first MD7As had a copper washer. Later in the serie the changed to copper sleeves. They are difficult to take out and the new sleeves must be pressed in. Its a job for a VOLVO technican.