TD5 injector testing / missfire

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steve's P38 RR

steve's P38 RR

Active Member
Posts
716
Location
Suffolk
Hi, I have a missfire and bad starting on my discovery 2 not had it long and done a few jobs / service to it these include egr blank middle box replacement pipe, all filters changed, injector loom, 4 glow plugs.

main question's are how can i test a injector and are they programmed to that cylinder, was thinking about running the engine with the rocker cover off and unplugging 1 injector at a time and one that doesn't make the engine run worse is faulty.

also after seaching on here found it could be just the seals on the injectors.

If i buy a used / recon injector can i just fit it or do they need programming to the ecu ?

cheers steve.
 
Hi Steve.

It,ll be really messy if you run the engine with the top off !.

You can, however, just hold the cover down while you run the engine. ( with an assistant ).

I assume you,ve checked for oil in the ecu,s red plug connector ? ( sorry, just read that you have ).

The injectors are coded to each cylinder, but can easily be re-coded with Hawkeye or Nanocom.

Del.
 
the injectors work best when programmed to a specific cylinder, also without rocker cover on your oil will **** out everywhere as td5 pumps oil into rocker cover to lube cam etc. try changing injector seals as they can give the symptoms you describe, and oil in the red ecu plug can, have you had fault codes read
 
yeah, ive read the fault codes but only with a sykes code reader, no faults showing on that. I've replace the loom as the plugs on the ijectors were full of oil but haven't had the plug off the ecu i'll do that today, i know I should of done that but didn't oil in the main plug to the injector loom on the head so didn't think it would get to the ecu.
 
steve's P38 RR said:
yeah, ive read the fault codes but only with a sykes code reader, no faults showing on that. I've replace the loom as the plugs on the ijectors were full of oil but haven't had the plug off the ecu i'll do that today, i know I should of done that but didn't oil in the main plug to the injector loom on the head so didn't think it would get to the ecu.
Click to expand...


Thats where it causes the problems.

You,ll be amazed that oil can travel all the way down the INSIDE of the wires and make it to the ecu.

Make sure you dissconnect the battery first.

Del.
 
took the plugs off the ecu and there as clean as a whistle in there did find one black wire had come out of the red multi plug so I refitted that and no difference.
 
You need to find out which cylinder is giving the problem.

Is there anyone near you witha Nanocom/Hawkeye ?.

Its quite longwinded, swapping injectors around to identify a duff one, and graet care needs to be taken when removing/refitting them.

I,d check the injector terminals for resistance first, if they all match, then I,d check resistance bact to the ecu. ( thats fron the ecu, through the injector and back ).

Del.
 
I'm going to try and take it over mansfield 4x4 in bury tomorrow morning get them to read it not sure which kit they have its a blue touch screen thing, there where able to read my p38 with it and re sync me ecu's etc.
 
NO codes showing at mansfields but on live data number 1 injector was reading a lot higher than the others at times, so new injector on order, i'm keeping my fingers crossed,

On a plus side got my bcm emabled for front fogs so they are now working and as heated front screen so can get my chipped screen changed now, Well as soon as the missfire is fixed.
 
steve's P38 RR said:
NO codes showing at mansfields but on live data number 1 injector was reading a lot higher than the others at times, so new injector on order, i'm keeping my fingers crossed,

On a plus side got my bcm emabled for front fogs so they are now working and as heated front screen so can get my chipped screen changed now, Well as soon as the missfire is fixed.
Click to expand...


How much difference was there on injector 1 ?.

If your injector is duff then, yes, the amount of " trimming " that the ecu needs to do to make it fire at the right time will increase, BUT, if the ecu cant " trim " the injector enough, it will log a fault against that injector.

Injectors are VERY expensive, an many people change them unecsessarily.

If your going to have the injector/s out then I,d suggest doing it before you buy a new one, and checking the condition of the copper sealing washers, as these become pitted and can cause rough running.

Continuity checks on the wiring will also cost nothing, and you could find you have chaffed wire somewhere.

Del.
 
Well the copper washers were pitted, but I didn't have the time to just do them and see if they made it better so stuck a new injector in number 1 at the same time as doing all the seals and checking the adjusters on the rockers were all set right.

I know it needs programming (but I can't get the car back there till sat) but they said I should notice it better even without programming but guess what it seems excitly the same as before?

So can any one tell me the position of the injector loom wires in the red plug on the ecu so I can check them.

I didn't think a broken wire was the fault as it smokes so much put this down the the injector over fueling and making a miss rather than not fueling at all the missing.
 
Get the garage to do an electronic compression test.This is done with an inductive clamp around one of the battery leads.The clamp is attached to an oscilliscope which shows the current taken by the starter motor.Five equal peaks shows good compression on all cyls.I've done plenty where one cyl is low,often a bent con rod or sha--ed rings etc.
its an easy test without getting your hands dirty.saves hours messing with swapping injectors etc with no improvement.But the owner is then faced with an even larger bill....
 
Next step if it was still the same after getting the injector programmed was going to be compression test, not heard of a electronic test before tho, Engine had a rebuild with new pistons 10k before i got the car, so hope not also as the problem has been getting worse and nothing was done (ie sucked in water) i'm hopping it electrical.
 
my disco 2 had oil in loom always had missfire 8 months aft new injector loom i found oil in the under bonet fuse box /grey multi plug top right hand side cleaned this and missfire gettin better also oil in maff plug if u have had oil in red plug before it can spread everywhere check all plugs you can find good luck
 
steve's P38 RR said:
Well the copper washers were pitted, but I didn't have the time to just do them and see if they made it better so stuck a new injector in number 1 at the same time as doing all the seals and checking the adjusters on the rockers were all set right.

I know it needs programming (but I can't get the car back there till sat) but they said I should notice it better even without programming but guess what it seems excitly the same as before?

So can any one tell me the position of the injector loom wires in the red plug on the ecu so I can check them.

I didn't think a broken wire was the fault as it smokes so much put this down the the injector over fueling and making a miss rather than not fueling at all the missing.
Click to expand...

Again an injector has been unecessarily changed !!!.

What I would do now is take the rocker cover off, and with the help of a friend, disconnect each injector in turn whilst holding down the rocker cover. This will tell you if its the injector/wiring.

You did,nt mention the black smoke !. You could also be suffering from a pooped air flow sensor, ( just take it for a run with this un-plugged to see ), or a collapsed turbo hose, or even a damp air filter come to bits in the air box.

Del.
 
50 pence said:
Again an injector has been unecessarily changed !!!.

What I would do now is take the rocker cover off, and with the help of a friend, disconnect each injector in turn whilst holding down the rocker cover. This will tell you if its the injector/wiring.

You did,nt mention the black smoke !. You could also be suffering from a pooped air flow sensor, ( just take it for a run with this un-plugged to see ), or a collapsed turbo hose, or even a damp air filter come to bits in the air box.

Del.
Click to expand...
Not a good idea,disconnecting injectors is not a nice thing to do to the ecu,and a failed AFM will only cause under fuelling - not black smoke.
What it does need is a diagnostic session with the right kit and someone who knows what to look for.
 
eightinavee said:
Not a good idea,disconnecting injectors is not a nice thing to do to the ecu,and a failed AFM will only cause under fuelling - not black smoke.
What it does need is a diagnostic session with the right kit and someone who knows what to look for.
Click to expand...


I wouldn't say its black smoke grey ish really its going back on the disgnostics tomorrow and getting the injector programmed and hopefully look into it a bit more, I have use basic code reader and can drive a injector at a time and they all clicked to sound's like there getting power ok, we'll see what tomorrow brings but not holding out much hope to be honest.
 
Was there any further progress with this?

I have a 2000 td5 auto that runs on 4 cylinders for up to 1 min when first started in the morning or at the end of the day (if cold). Also it won't drive until it's running on all 5, you can put it into drive and try to accelerate and it won't even pick up any engine revs.

Its had a cylinder head so all the sundry bits swapped the injector loom replaced and the ecu red plug cleaned out regularly, its also had silicon hoses and a new turbo, fuel filter swapped and system purged, so id be interested in any suggestions as I had it down now to an injector.
 
I'm with 50 pence on this one. Had the same problem which was cured with new injector seals and washers. The copper washers were knackered.
 
It dosen't look like i updated this,

the problem is no compression on number one cylinder, so the heads got to come off for inspection, when weathers better and have so funds to repair whats needed.
 
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