Injectors service

[Trevor_swfyc]

My Volvo Penta 2002 was proving difficult to start, nothing new in that I know. I decided to take off the head and have a peek, after 14 years untouched the top of the bores, valves, pistons and head were well carboned up. I have cleaned it all up ground in the valves and intend to replace the valve guide seals. I have removed the injectors cleaned them in petrol and they look ok. I have been told I can get them tested but if it cost as much as replacement parts might I just as well get new injector tips and be done with it what does the team think. What should I expect to pay?

Thanks
Trevor



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[Mudplugger]

Trevor, normal price for Injector re-con in Colchester are is £30.00 each, if you are anywhere near Lexden Diesel on the Hythe are pretty helpful.

<hr width=100% size=1>Tony W.

 

[snowleopard]

the basic test is to connect them up and squirt fuel through them, looking for an even mist with no visible drops. this can be done by taking them out and connecting them to the feed pipe pointing out instead of in, then crank over.

caution: stand well back, the extreme pressure is enough to drive the fuel through your skin if you get in the way of the spray.

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[pvb]

True, but...

That's quite true, but I don't think we amateurs can really assess if an injector is working properly. My preferred approach is to take them to a commercial vehicle diesel specialist, who will typically charge much less than a marine engine dealer to check them.

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[paulrossall]

Re: True, but...

My local commercial vehicle (Lucas agent) tests them free of charge. Only takes them one minute each injector. Do not go near a marine engineer with them unless you have more money than sense. IMHO. Paul

<hr width=100% size=1>" there is nothing-absolutely nothing-half so much worth doing as simply messing about in boats".

 

[Avocet]

Re: True, but...

I'll second that. My Lucas depot did mine while I waited (OK I've only got one injector!) They check the spray pattern, the opening pressure, the delivery volume and the cut-off point I think. I had carefully written down all the injector data from my manual but they didn't need it. They can get the information off the top of the injector.

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[Althorne]

Trevor whatever you do DO NOT do as snowleopard suggests. Some 45 years ago when I was a new apprentice a senior mechanic foolishly did a similar thing. The jet of diesel pierced his hand and entered his blood stream. Although I cannot fully recall the outcome I know he almost died as a result of some poisoning and was permenantly crippled afterwards. With this day of compo' madness I'm very surprised a usually very informative snowleopard dared to publish the idea.

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[ongolo]

No snowlepard is right, you can test injectors this way, there is no danger if you dont put your hand in front of the injector. In any case that fine mist is dangerous only at close distance, having not much mass, this mist looses velocity (and danger) immediately.

Also, I dont think the injector is rated how much fuel it injects, that is decided by the injection pump, so it is only for proper spray and opening pressure injectors are tested. That is on Bosch and related systems, I am not sure how the GM type works, where pump and injector form one unit.

I dont want to know either I boycott USA.


regds ongolo


<hr width=100% size=1>1000 dream about it, 100 talk about it, 10 start and 1 completes it

 

[TonyBrooks]

If cost is a factor and you are anywhere near Reading during a lunch hour, I will do the basic tests in front of you (for free), but to be 100% accurate I would need the break/opening pressure.

Tony Brooks

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[Trevor_swfyc]

Thanks all for the advice, fortunatly although my knowledge of injectors is limited I did know to keep fingers clear of the injector when under test. As for testing myself it sounds as though as I have no experience of good and bad, I might end up kidding myself they are working fine when they are not. So I will be taking Mudpluggers recommendation and take them to Colchester Injectors.
I think I have done well to get 14 years out of them without any service but for all I know this might be normal.

All the best and thanks.
Trevor

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[anchorhandler]

I cant believe there is an argument about testing diesel injectors 'in-situ'!!!!!!!!!

This should NEVER,NEVER,NEVER be done unless the injector is removed and placed in a proper injector 'popper' tester.

Diesel injectors open and release fuel at around 270-350 bar depending on the injector....thats nearly 175 times the pressure in an average car tyre!!!...Should the atommised mist at the outlet of the injector come into contact with skin, it WILL penetrate and cause blood poisoning!!!

Secondly, even in you stand well clear of the injector when being tested, you stand a good chanch of inhalling the atomised fuel droplets. This is dangerous in itself as diesel fuel is a relatively complex mixture of aromatised hydrocarbons containing potentially carcinogenic elements.

Thirdly, what does it accomplish?...Nothing, you cant tell at what pressure the injector is opening at (which will vary greatly as the injector spring weakens with age) this being the most impotant carachteristic of an injector. You cant tell if the spray pattern is correct!...in fact you can hardly tell anything usefull at all!!!

THERE IS NO ARGUMENT HERE......NEVER TEST INJECTORS OUTSIDE OF A SPECIFICALLY DESIGNED TEST APERATUS!!!!!!!!

Simon

<hr width=100% size=1>I'v got 2 ears.2 eyes and 1 mouth....if only i could use them in that proportion!

 

[dickh]

Definately take them to you local injector man - I had 3 injectors overhauled at a cost of under £100 a couple of years ago - they didn't need it but thats another story!

<hr width=100% size=1>dickh
I'd rather be sailing... /forums/images/icons/smile.gif

 

[charles_reed]

Take them to a good injector servicing company - these are few and far between and yellow pages might help, far better to phone up a big haulier with his own workshop and find out who they use.

Bench testing is about a 5 minute job and frequently they'll do it for nothing - adjustment will cost about £8-£12 per injector. If you need a rebuild the cost is in the new parts, allow about £40 per injector. However injectors (probably Bosch) will do about 10,000 hours before needing rebuild and your Volvo would have been scrap long before that happened.

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[Croucher]

Trevor
It may be easier to go to Basildon's Burnt Mills estate.
Commercial Diesel firm where I took my injectors a few years ago. However can't remember their name Price compared with Mudplugger's as I recall but did take a couple of days. I will have a look tonight at receipts if it helps.

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[ongolo]

And I cant believe how many people have only theoretical knowledge on a subject and argue about it.

Injector opening pressure ranges from about 110 bar on simple Lister engines, to 150 bar small Isuzu engines, Bosch used to be 170 bar but have gone up now to 220 bar for better atomisation, Some Cat engines have an opening pressure of 400 bar and common rail pressure on elctronic disel system used to be until recently 800 bar but have now gone to 1200 bar.

If you keep your extremities further than 4 inches (100mm) away from the injector, it cannot injure you anymore, gas has very little mass and looses velocity almost instantly.

What you can well establish, when your engine does have a bad knock, does not start or smoke white (not blue) is by removing an injector and test it as has been described. If it sprays it means it is ok even if the fuel efficiency is not good, but if it drips, you have a problem. If you ever have seen a faulty injector drip, which I daubt, you will know that there is a problem.

As far as inhaling the atomized fuel goes, do you smoke? Every injection pump specialist has inhaled fumes many times. We also wash our hands in diesel or petrol which is also supposed to be wrong.

How do you bleed your system? Do you wear a protective suit for that too? And do you have a special extraction fan to remove the diesel fumes when the engine heats up after bleeding it?

In idle my injectors inject about 6.4mg (or 0.0064gramm) of fuel which is almost nothing if dispersed in the 9 cubic meter of my engine room.

And have you seen an injection tester? It is a little hand pump, with a gauge on top, a little tank and a pipe for the injector to go onto, and then you pump and spray. Into where ever. The nearest one is about 20m (meter not miles) from me.

Get real, how are you going to establish one day some 2 weeks from the nearest port, whether you have a big end going or whether you have an injector dripping? Symptoms can be very similar.

One prblem overlooked is that you should not spray onto a hot manyfold, but that is not a problem either, by the time the engine is cold enough to remove the injector, the manyfold will probably be below the flash point anyway.

This here in my opinion is related to PRACTICAL BOAT OWNER, and for all practical purposes, when you on your own and have problems, you have to fix them. And it is no use to scare the unexperienced into paralysis.

regards ongolo


rega

<hr width=100% size=1>1000 dream about it, 100 talk about it, 10 start and 1 completes it

 

[anchorhandler]

''""If you keep your extremities further than 4 inches (100mm) away from the injector, it cannot injure you anymore, gas has very little mass and looses velocity almost instantly.""""

Atomised diesel is not a gas, it is made up of finite droplets of diesel which, although small still represent a mass. Granted your hand would need to be within a few inches of the nozzle in order for the diesel to penetrate however are you really saying that, after considering the potential consequences of blood poisoning, you recomend that everyone suffering injection problems goes and tests them into the engine bay?.........and how long do you think it would be before someone, somewhere (after listening to your advice) gets a bit too close to the tip of the injector by accident or by other means and unfortunately suffers the consequences?...A mate of mine is now permanantly scarred after spending several weeks in A&E due to a hydraulic hose bursting while we were 'jacking' off a cylinder head. The hose contained hyd-oil at 400 bar which attomised into a high pressure jet and cut through his stomach!


""""What you can well establish, when your engine does have a bad knock, does not start or smoke white (not blue) is by removing an injector and test it as has been described. If it sprays it means it is ok even if the fuel efficiency is not good, but if it drips, you have a problem. If you ever have seen a faulty injector drip, which I daubt, you will know that there is a problem.""""

Granted a dripping injector will cause diesel knock (as well as afterburning and poor (early) injection), but to suggest that just because an injector sprays...it is ok!!!....Of course since i dont have any experience, i would never had seen the effects of repeated early injection/ignition on bottom ends or piston crowns that i have never had to change as a result.


""""As far as inhaling the atomized fuel goes, do you smoke? Every injection pump specialist has inhaled fumes many times. We also wash our hands in diesel or petrol which is also supposed to be wrong.""""

No... i dont smoke but i certainlt dont go around advocating that isnt unhealthy for you either!!! Just try to find a reputable injection company that doesnt have guards around the testing equipment!!! (as required by the HSE!)

How do i bleed an injection system through??? I Bleed any injection system through the proper way, by slackening back the compression fitting or gland at the inlet a turn or two then turning the engine over. I dont really see how taking an injector out of an engine and injecting fuel through it into the engine bay "bleeds" the system as this is EXACTLY what was happening before but now instead of the injector spray being confined to a cylinder, its blasting out into the engine room!...Find me any engine manual that suggests to bleed a system through this way and i will happily do it!


""And have you seen an injection tester? It is a little hand pump, with a gauge on top, a little tank and a pipe for the injector to go onto, and then you pump and spray. Into where ever. The nearest one is about 20m (meter not miles) from me.""

Refer to the Health and safety agency for that one!!..unbelievable, you must believe that asbestos pipe lagging is good also?...i'm sorry, i dont have much time for the "because its always been like that" attitude!


Anyway this is boring me now, i've had enough of 'scaring the inexperienced' into staying that little bit safer....

Simon


<hr width=100% size=1>I'v got 2 ears.2 eyes and 1 mouth....if only i could use them in that proportion!

 

[colvic987]

i am in the process of getting both copper sleeves on my md7a replaced and the injectors serviced, given a price of £120 approx, went in to get the cylinder head gasket , £48 excl vat, £24 for the manifold gasket, the gaskets alone will be nearly 40% of total price, i was expecting extortion, but not to this level, (another satisfied volvo customer)....

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[Avocet]

I'm with Ongolo on this one! My injector sprays at 112 bar. My workshop manual tells you to crank the engine with the injector out and look at the spray pattern - it even gives a picture of a correct and an incorrect pattern so you know what to look for. It tells you to keep eyes and skin from coming into contact with the high pressure spray for the obvious reasons that have been stated but there's no more drama than that.

When I was a kid we were told to look before we crossed the road. At this rate I'm expecting to be told that I must advise my kids never to cross roads!

...or go to sea for that matter!

I think anyone who has stood on a petrol station forecourt on a warm day for a few minutes will have had plenty of exposure to diesel vapour!

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[anchorhandler]

Hello Ian
Thanks for your comments, it made me go back and read my original post to realise that maybe i was 'overdramatising' the scenario.

My original point though still stands, when your 'broadcasting' to a large audience such as on this forum, you have to give advice which err's on the side of safety. Who knows how many people have read this thread from around the world, some experienced with engines, others not. What i wanted to convey to was to treat high pressures with respect, especially high pressure fuel systems. These systems have the potential, especially if mis-used, to cause serious harm.

I have to say, i'm surprised to hear about your engine manual though....how old is it?

regards
Simon


<hr width=100% size=1>I'v got 2 ears.2 eyes and 1 mouth....if only i could use them in that proportion!

 

[Avocet]

Hi Simon,

Yours is, obviously, a fair point too! - especially in the light of some of the stuff on the "getting sued" thread! My feelings, though, are that I need to make some sort of stand against the current tide of "compensation culture". 20 or 30 years ago, nobody would have thought twice about giving all sorts of help and advice that they wouldn't dare give these days. Hell, I now have to think twice about offering someone a lift these days in case they have to use the middle rear seat which has a "lap" rather than a three-point seat belt! Similarly, I think kids these days get much less opportunity for adventure on extra-curricular activities because teachers are getting scared of having their butts sued off if something goes wrong! My kids aren't even allowed to play conkers any more!

Although we (as a society) might have fewer accidents, I'm not sure we're any better off for it!

Anyway, I could rant on all morning but my employer would probably take exception so I'll shut up - but I understand where you're coming from, mate!

The manual, by the way, is a BMW marine one from (I guess) the early-to-mid 1980s.

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