Fuel Injectors .. Replace or not?

[VADROUILLE]

1000 hours sounds like a very short lifetime to be testing injectors.

Taking your word for it I have just looked in Bukh, Yanmar and Volvo manuals and none recommend any period at all. An internet search throws up vehicles that have done 600,000 miles without ever having injectors serviced. My VW diesel van did 160,000 miles without ever having the injectors removed.

General advice seems to be to do nothing unless the performance of the engine justifies it.

I have seen many marine diesels that have vastley improved over simple injector testing. You would be surprised at how small the build up of carbon needs to be in order to lower the performance of your engine. to put things in perspective, if you put your hand in front of an ijector whilst it shot out diesel, you would remove your hand to find a nasty wound. The tolerances are that small that you would be surprised what a simple test/clean would do.

Its hard to judge a marine diesel as all the engines in boats get a completley different usage. One engine may get 500 hrs put on in a year and another may only have 50 hrs put on in a year.

You are correct vyv, i have two engine manuals on board for the md22, i have ther perkins version and the volvo version. the perkins gives no such recomendation on when to test injectors, however if memory serves me the volvo does, (i have the do it youself guide for the volvo which goes more in depth to the md22, its more comprehensive than the standard manual you receive) When im next at the boat i shall double check and post where my source of information has come from.

As far as my marine engineering view goes, i never compare the standard road diesel with a marine one, the usage on the two engines are completly different and a comparison between the two is an unfair one to make.

putting any sort of projected maintenace on a marine diesel is hard, as i said before, every engine out there gets a completley different usage, as a rule of thumb i always recomend every 5 years to remove and test injectors.

Its simple and easy enough for the average yachtsman to do and all he needs to pay for is the testing of the injector, and any new parts (once an injector is removed you must allways replace the copper washers with new ones) I see it as easy and cheap preventative maintenace that could, in the long run, save the average yachtsman alot of money.

not naming any companies, but i was shocked to here that a well known east coast outfit charge £47.50 plus vat an hour for any engineering work.

it then makes the £100 test sound cheap...........

Again, the above is just my view.

 

[GAJ]

This thred has facinated me. I will try the Italian method and the adding of two stroke oil is compelling reading. Has anyone else added 2 stroke oil and noticed any difference. Also what sort and what ammount did you add per 100 L of fuel?

Why not use a diesel fuel additive that stops the bug and lubricates the pump and injectors at the same time instead of just 2 stroke as a lubricant which still leaves the tank open to bug attack?

My farmer pal, who is a time served motor engineer, says that mixing engine oil and paraffin for use in diesels was standard practice when 'he was a lad' is paraffin cheaper than diesel?

 

[vyv_cox]

I can understand why a little lubricating oil (2 stroke or otherwise) might be a good thing for older diesel engines forced to drink low sulphur diesel, but the article you quote to back that up doesn't do you any favours (IMHO) - it reeks of snake oil rather than 2 stroke oil! Next you'll be telling us to put magnets around the fuel lines

I suggest you Google '2 stroke in Diesel' which is what I did. There are hundreds of sites that discuss it, mostly owner groups for 4-wd vehicles and such like. I couldn't find any negative comments after 20 minutes or so. It has been discussed in recent threads here and many seem to have done it successfully.

 

[maxi77]

not naming any companies, but i was shocked to here that a well known east coast outfit charge £47.50 plus vat an hour for any engineering work.

it then makes the £100 test sound cheap...........

Again, the above is just my view.

On the other hand garages apparently can charge up to £100 an hour, it would be interesting to know what you as some one with practical knowledge would consider to be a reasonable hourly rate.

 

[VADROUILLE]

On the other hand garages apparently can charge up to £100 an hour, it would be interesting to know what you as some one with practical knowledge would consider to be a reasonable hourly rate.

If i had my own outfit i think a fair reasonable amount would be £20-£25 an hour.

average that over an 8 hour day 5 days a week makes a nice monthly wage. However that is all based on regular work, however, as i understand it there is allways work in the marine engineering world.

But as i said before, this is all just my point of view. There are people out there who do charge £20 an hour, even less than that. They are normally reliable to and bend over backwards for you.

 

[Heckler]

This thred has facinated me. I will try the Italian method and the adding of two stroke oil is compelling reading. Has anyone else added 2 stroke oil and noticed any difference. Also what sort and what ammount did you add per 100 L of fuel?

The MD22 is a Perkins Prima 50 developed by them or the Montego Mestro diesel cars. It was developed rom the 2 litre petrol engine and has a vey low compression ratio (17 - 1) as opposed to a normal diesel engine which is 20 plus. It is a direct injection engine ie no pre injection chamber. It was a surprise to BL in that it gave very good fuel economy. 50 plus mpg not unusual, beore the advent o common rail diesels. One of their idiosyncrancies is that they smoke on start up, a result of the low compression ratio. BL dealt with this by fitting a doofer on the side of the Bosch VE pump that advanced the timing on the injection when it was cold. That i why when you see these engines for sale on Ebay ( they use them in landrovers as a cost efective way o increasing the mpg) you will see the "thing" on the side of the injector pump aand the associated temp sensor gear.
It is normal for these engines to smoke on start up and give a light blue haze when running.
Mine has done several thousand hours and does this, yet consumes less than half a litre o oil a year. If it aint using oil, and the consumption of diesel is ok, leave it alone. If you have a misfire or somesuch then contemplate having the injectors serviced.
Stu

 

[Ubergeekian]

General advice seems to be to do nothing unless the performance of the engine justifies it.

One of the side effects of my blocked exhaust port was carbon build up inside the head, including across the injector nozzle. But yes, the performance made it obvious that Things Had to be Done.

 

[maxi77]

If i had my own outfit i think a fair reasonable amount would be £20-£25 an hour.

average that over an 8 hour day 5 days a week makes a nice monthly wage. However that is all based on regular work, however, as i understand it there is allways work in the marine engineering world.

But as i said before, this is all just my point of view. There are people out there who do charge £20 an hour, even less than that. They are normally reliable to and bend over backwards for you.

Perhaps possible for some one who is self employed, with no capital involved in premises or tools, no ongoing training to keep up to date and so busy that every one is kept waiting.

Overheads vary depending on the set up but every one has them. You cannot work a full week, life does not work like that and you need holidays, sick time, training time. When I worked we budgeted on only getting on average 25-30 hours work a week from people based on a 37 hour week. You need tools, stock of spares, accountants and lawyers, you need to pay for all of these.

 

[tjc]

Resurrecting an old thread..........

I have a some smoke on start up but that disappear after 10 mins or so but the sheen does not or certainly when idling. Uses no oil though nor coolant. It does misfire when started up from cold for the first 30 secs or so...injectors due a once over?

TIA

 

[sailorman]

how many hrs have they done

 

[tjc]

That was quick........ about 800 probably - sat for bit last year though.

 

[sailorman]

That was quick........ about 800 probably - sat for bit last year though.

i am up to just over 900hrs & no different from new 11 yrs ago

 

[tjc]

in that it misses for a short time?

 

[sailorman]

in that it misses for a short time?

so does my car @10K mls on a cold morning