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Fuel injectors clean or replace ?

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The trouble with working nights is you get plenty of time to read and watch you tube videos, hence you tend to find find more potential problems you didn't know you had.

For example: I started watching videos on cleaning fuel injectors, the thought then occurred to me that I have never done mine all be it one instance of adding Redex to my fuel tank pre-mot.

Reading deeper into the subject there are several symptoms which suggest blocked or worn injectors ie poor idling (rough uneven), poor fuel economy, performance worse when engine warm than cold and smoke at start up. All of these faults I have so it got me thinking, how long have they been in the vehicle is it time to replace them are they just blocked or worn ?

So I priced a set of new injectors on eBay just to get an idea, as its easier for me to change them than go through the cleaning systems I have watched on you tube. Then I saw the price £165 to £200 for a set, now the cleaning option is starting to look more appealing :o.

The ones I watched where for saloon car diesel engines but principle would be the same, taking the feed and return through a plastic bottle containing the cleaning solution (different ones recommended different cleaners depending which video you watch).

The other option was to removal of the injectors and soak in a cleaning solution then scrub with a brush ? Again no specific cleaner stands out, people seem to have there own preferences.

I have in the past as I said earlier used Redex fuel additive, where you just add it to your fuel tank when you fill up and it cleans your system as you drive. Not sure if this is an effective method but is easier than the other methods above (getting lazy in my old age).

As I am now resigned to doing something about this over the next few months, I would like some advice on what others have used and how effective it has been ? Or would I be better saving up buying a new set of injectors and keeping the old ones as spares and cleaning them at my leisure ?

I am planning some longer journeys this coming year, so really want to get the old girl running as smooth as I can before then. If a new set of injectors is my best option, all well and good Ill bite the bullet. But in an attempt to save money and achieve the same outcome I am prepared to try the cleaning option if its proven to work.

As always any advice is welcome.

Regards Ian

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Before you choose to replace or clean having them tested would be the best solution. A reputable Diesel specialist should be able to pop test and leak test them for you then offer advice if anything is required. 

No point in cleaning them if they are need overhauling or are knackered in the first place. 

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Personally, I've never found cleaner makes a blind bit of difference so if i was at the point where performance was affected, i'd start looking at testing and reconditioning them as mentioned above.

You could try a can of cleaner, but i doubt it'll do much more than a placebo effect of smoother running!

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As per above,  send them to Bosch diesel specialist and get them looked at, out with injector issues,  The symptoms you've described can also be down to worm piston rings and valve seals amongst other things. I replaced mine a while ago I "think" I noticed some improvement but no huge night and day differences. 

My truck still smokes like a train when cold.  I've put it down to an old well used engine that needs a re build... 

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To be honest it only produces smoke on initial start up, after that no real signs of smoke. it's the rough idling speed and general performance that bothers me.

But as you said could be general wear its an old engine, although when it was in the garage just before Christmas for a new timing belt the mechanic said it sounded good and nothing to worry about. Maybe i am just being paranoid, to make sure will follow the advice and go to a Bosch diesel specialist to get them checked.

Thanks for the advice


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Hmmm you say it's just had a new timing belt...  I'd probably check the timing again... had some interesting experiences with getting that right this summer on a D1 300tdi, it really doesn't take much for a slightly miss timed belt to cause rough running... 

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To be honest it was running the same before I had the cam belt changed.

I mainly noticed the idle problem when sat at traffic lights, it started producing a little more vibration than previous so use to touch the accelerator slightly to smooth it out.

With respect to the cam belt change I took it to my local Land Ranger service garage who are specialists in Land Rovers, they are pretty clued up. The reason I paid for the timing belt to be done was I had heard a few stories of timing issues following timing belt replacements, so took it to the professionals (chickened out of doing it myself).

Ive also noticed a tapping noise (which is worse when I first start up) which I put down to oil starvation or poor set up of tappets (I did adjust to 0.20 and checked caps but little impact). Must admit recently I have fitted new door cards, rear seats and carpet so sound is more deadened in the cab than previous, so engine noise is probably more noticeable.

I asked the Land Rover mechanic about the tapping (after he had done my belt) and he said there is nothing to worry about he's heard a lot worse (seems to think its just diesel knock, whatever that is ?), in fact he thought it was a good sounding engine for it's age.

I have also read that the brake vacuum pump failing can make a similar noise, need to use the old screw driver stethoscope to track it down. Although the mechanic didn't pick up on that, again maybe me being paranoid.

So rather than a timing issue I would suggest it's more likely my engine is getting worn and tired or my fuel delivery system needs some attention.

To be fair once the engine is warm it runs reasonably well and on motorways I can accelerate with no problems and cruise at 70 mph. Not really been on a long journey in it for a while so don't know how it would behave then ?

As I said previously maybe it's me just being a bit paranoid, with the smoke at start up and particularly the rough idling.

I tend to get roughly 250 miles out of a full tank most of my routine journeys are traveling to work and back the journey is 80% motorway, don't know if this is good or bad fuel consumption wise ? Longer journeys I use to get closer to 290 or 300 miles before I needed a fill up.

Thanks for the follow up Mav.

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