TD4 Injector advice needed please

Hi it's me again! It's been some time trying to sort out a miss fire wobble thing on acceleration - see other posts for history but I recently took it to a LR Indie who suggested I change the LP fuel pump and based on a diagnostic which showed injector one over fueling (a new reconditioned one!) suggested I swop it around to see if the fault followed it - we'll it did!

Here is a photo of the screen showing Injector 4 reading higher than others.

My question is does anyone know if this is enough to cause a wobbly hesitation patch?

angeloc said:

Hi it's me again! It's been some time trying to sort out a miss fire wobble thing on acceleration - see other posts for history but I recently took it to a LR Indie who suggested I change the LP fuel pump and based on a diagnostic which showed injector one over fueling (a new reconditioned one!) suggested I swop it around to see if the fault followed it - we'll it did!

Here is a photo of the screen showing Injector 4 reading higher than others.

My question is does anyone know if this is enough to cause a wobbly hesitation patch?View attachment 33298

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it could be that the other 3 injectors are reading low and the (new recon injector)is reading normal.i think removal of injectors and a proper bench test is the only way to find out,dont rely to much on computer diagnostic

normally if its a LP pump or pumps then you will get a mill light warning or go into limp home mode , its best to make sure the pumps are delivering correct fuel before looking at hp pump or even injectors ,not forgetting the simple clogged up fuel filter . . . . . .

Thanks for replies. The injectors were tested on a Delphi unit off the car and The company said 3 were ok one was not so bought a recon from them - this is the one that appears to be a lot different.

LP pump I changed last week because diagnostic showed it just below acceptable pressure - new one good. HP pump good as well but on the lower side of in spec.

Fuel filter changed 3k miles ago.

I use Millers in fuel as well.

Have you done basics like compression test etc?

Diesel Do said:

Have you done basics like compression test etc?

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Changed injector harness.

It seems fine - not done a compression test other than that done on a diagnostic - I believe it measures the resistance on the stater motor during cranking.

I have had 2 Sole trader mechanics one a LR Indie as well as a Diesel specialist company.

I going back to the company who sold me the recon injector on Tuesday with the car and they are going to look at it for me - it could be a faulty recon although it could be that when they tested the other 3 they missed something.

I was just wondering if the variance seen on the screenshot is something that flags up something to go to.
Cheers

angeloc said:

Changed injector harness.

It seems fine - not done a compression test other than that done on a diagnostic - I believe it measures the resistance on the stater motor during cranking.

I have had 2 Sole trader mechanics one a LR Indie as well as a Diesel specialist company.

I going back to the company who sold me the recon injector on Tuesday with the car and they are going to look at it for me - it could be a faulty recon although it could be that when they tested the other 3 they missed something.

I was just wondering if the variance seen on the screenshot is something that flags up something to go to.
Cheers

Click to expand...

I believe it looks for a speed variation in the crank sensor, ie low compression spins faster. Have you swapped them round yet to see if it moves cylinder?

angeloc said:

Thanks for replies. The injectors were tested on a Delphi unit off the car and City Electro Diesel said 3 were ok one was not so bought a recon from them - this is the one that appears to be a lot different.

LP pump I changed last week because diagnostic showed it just below acceptable pressure - new one good. HP pump good as well but on the lower side of in spec.

Fuel filter changed 3k miles ago.

I use Millers in fuel as well.

Click to expand...

Oh thats all good then, only i know it gets boring on this forum harping on about basic checks first ,but you will be surprised how many dive in too deep cos some bod on a phooter pulls there pants down , but in your case you've done the basics first, well done Earthling so yes leak off test or injectors appears correct . . . .let us know

Diesel Do said:

I believe it looks for a speed variation in the crank sensor, ie low compression spins faster. Have you swapped them round yet to see if it moves cylinder?

Click to expand...

Yes I swapped no.1 for no. and it followed the injector - does it look like no.4 is faulty? It is the new recon one.

If it follows the injector around and that's the only variable you change it can really only be a duff injector! New or not it sounds faulty to me

Diesel Do said:

If it follows the injector around and that's the only variable you change it can really only be a duff injector! New or not it sounds faulty to me

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I agree - sounds like it to me but trying to get suppliers to agree is a bit more difficult. It follows a series of bizarre incidents - I had a duff Injectir and sent it away for exchange but it was lost in post and I didn't send it recorded (Doh!) so I bought a second hand one that turned out to have the wrong nozzle in it - found out when all 4 were tested. A local ish diesel service had a recon for £120 so I bought it - it looks as though it's faulty but they have checked it on car then I took it out and down to them - They say it passed their tests but couldn't give me a read out because they had a fault with their computer - alarm bells. Anyhow I am at this point now and it's booked in on Tues - they seemed ok on the phone - we will see.

Just got to persist with them? Do the injectors need coding on these for manufacturing tolerance! If there's a big variation it can make them lumpy! I'm not an expert on td4s but depends how rough it's running as to whether it's just not been set up when it was fitted or it simply duff!?!?

When I had an injector that was quite bad, the difference on the computer was way more than that, pretty sure one was up to 20 on the scale or something silly. But, that was quite a duff one!

The injectors don't need coding my TD4 is a 2003 one - much later ones do but not this one.

The miss is not huge and in normal driving the car is powerful and smooth - its just when you are pulling away in second gear the miss sets up what can be described as a wobble or shimmy that is felt through the car then it goes, although the LR Indie said he could feel a bit all the way through the gears.

It is getting progressively worse as well.

It's the same with the prop off as well.

I have changed so much stuff on this car hoping to cure it - New VCU, new Duel Mass Flywheel Clutch and slave (the slave went so I had the lot done) 2 new ft drive shafts, new taper bearing on IRD, etc etc

If I put my Synergy on with either MAF Bosch or Pierburg it gets worse as if it is what I suspect it's over fuelling.

So it sounds like it sets up a judder in the drive train? Have you changed any mounts? Do you pull away in second from a standstill? I'm doing my rear diff mounts at the mo (the rear ones are knackered front ok) which appears to be the cause of a major judder caused by a minor clutch judder. It's very hard to remote diagnose. Does it do it at low revs, is it only as you're releasing the clutch, is it a set rev range?
The position you're in at the mo, I personally would want that injector replacing and get it running evenly on all four cylinders. Then progress with the judder if it's present still.

Hi angel......thought you'd be on yer bike trip by now.
When i had an injector on its way out I would get a wallowing feeling at constant throttle, near the end of it it would sound like a missfire on a 4 stoke until you reved it...... Also found synergy made it worse.
I'll be in angelsey 2nd week of August,and I I always have 1 or 2new injectors with me if that's any help.....if you need to test?

I start off in First so no probs there. I have changed the rear diff mounts, the VCU hangers and the front lower engine tie rod. I took the left hand gear box engine mount apart - all good there and I put a camera on the right engine mount again all good.

I have had the car on ramps with 4 wheels off the ground running and the vibe comes in at approx. 2225 to 2500 rpm.

I am going to insist on a replacement injector and see what happens then.

Cheers

mjrimmer said:

Hi angel......thought you'd be on yer bike trip by now.
When i had an injector on its way out I would get a wallowing feeling at constant throttle, near the end of it it would sound like a missfire on a 4 stoke until you reved it...... Also found synergy made it worse.
I'll be in angelsey 2nd week of August,and I I always have 1 or 2new injectors with me if that's any help.....if you need to test?

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Hi mj - I would normally be going but I took a very early retirement this year so between trying to get some work done around the house and sorting this out I between bouts of stupid weather I am running late. I will probably do a UK trip this year.

Thanks for the offer - hopefully it will be sorted by then. Enjoy Anglesey.
Cheers

hi angeloc it could be possible that if a injector is down the engin is shuddering just a possiblilty hope this helps

Yes my thinking is that it's an injector failing under a rev load range which sets up a wobble until it sorts itself out.