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alexatnd

Member Since: 19 May 2015
Location: Yorkshire
Posts: 278

injectors all high impedance

ok so given that im fitting a new. ACR cylinder head and cam to my TD5 i thought I'd. go the whole hog and get the injectors tested/refurbished, so sent them off to United Diesel Fuel Injection Services Ltd to be checked out.

Injectors were deliverd next day and. then i got a phone call that afternoon saying all 5 injectors were showing high impedance andn failed at 1st hurdle. As they cant get the electrocal parts, not much they could do with them.

Basically. ws told that while they would work, highly likely to cause problems when running/warm with fault codes appearing.

Net result is I'm waiting delivery of a set of reconditioned injectors costing slightly more that price of. refurbing the ones ive got.

Now wodering what could have caused them to go phut!.

Gertie had been sitting for a month or so b4 i put a newly charged battery in to drive the 10 ft to put nose in my garage. Problem was when i turned the ignition key, was treated to loud relay clicking noises from area of fusebox behind. gear lever and the EMS and glowplug lights were flickering at a high rate.
Switched off, gave all the relays a re-seat , tried again and she started almost 1st time.

Basically nose in garage, injectors and head off, left injectors sitting on top of chest freezer near doorway till i sent them off a couole of days later.

Not aware of any. injector fault codes ... gues too late to look now.

So question is what can i test b4 i connect up the unexpected expensive. injectors as i'd grumble a bit if these ones go phut! as well

A Santa - 1977 Series 3 - new chassis, tub, disc brakes,SU Carb
Gertie - 1999 110 TD5 - like a Phoenix from the ashes back on road... almost
Effie - 2004 110 TD5 County

23rd Nov 2024 12:00pm

MadTom

Member Since: 10 Sep 2013
Location: Olomouc
Posts: 625

Electrical part of injector is just a coil. Mechanical parameters of the coil are fixed (diameter, length, diameter of used wire and number of turns), so you can easily measure the reasistance of the coil.
When operated, coils in injectors are driven by ECU - pulsed voltage 85V with approx. 25A of current. Measuring of the resistance cannot with some multimeter cannot damage the injectors.
TD5 engine ECU is tightly controlling the current through injectors, so if you had not any problems with engine running of fault codes, I would check the injectors by someone else. It is wery unussual to have all injectors broken. I can imegine it only with broken ECU - burnt through in multiple places, as it has switches for both positive and negative wire to injectors. "Drobek" = The Small One - Discovery 2, "Blufínek" = The Blue Thing - Defender 130, and for me at least Ford Mondeo

26th Nov 2024 9:37am

alexatnd

Member Since: 19 May 2015
Location: Yorkshire
Posts: 278

Many thanks for the reply. yeah, bit twitchy about installing. new ( refurbed) injedtors if theres a chance of them getting trashed.

Suppose 1st thing is to plug in my LynxEvo to see if there are any errors. guess can do that even if the injectors arent connected just to see if there are any existing error codes

Have found a company that will check out the ECU for me ... obviously at a price ...
A Santa - 1977 Series 3 - new chassis, tub, disc brakes,SU Carb
Gertie - 1999 110 TD5 - like a Phoenix from the ashes back on road... almost
Effie - 2004 110 TD5 County

26th Nov 2024 11:27am

MadTom

Member Since: 10 Sep 2013
Location: Olomouc
Posts: 625

You can connect injectors (old ones) without mounting them in the engine head, and then test them through diagnostics - ECU can click them. Do it more than once for all injectors and look for any faults in ECU. "Drobek" = The Small One - Discovery 2, "Blufínek" = The Blue Thing - Defender 130, and for me at least Ford Mondeo

27th Nov 2024 9:13am

TexasRover

Member Since: 24 Nov 2022
Location: Paris
Posts: 1084

2002 Defender 110 Td5 DCPU Chawton White

Yes I would take the feedback from this specialist with a grain of salt. Possibly they misread the specs because it would be very unlikely that ALL 5 injectors removed from a running engine would all be faulty, especially since there is not much to the electrical parts of an injector.

Note that Td5 injectors are not like modern Common Rail injectors, maybe the expert got confused. Where on common rail the solenoid opens to allow flow, on Td5 injectors the solenoids stop (disrupts) the pressure and fuel outflow once enough fuel has passed by bleeding off the pressure to the return line. The pressure does not come from a common rail pump but instead is build up within the injector by the camshaft, same system as used on large industrial diesel engines.

27th Nov 2024 9:33am

derbywill

Member Since: 25 Mar 2010
Location: Derbyshire
Posts: 559

I was talking to an injector specialist who seemed pretty clued up on Td5 injectors and said the coil has a really tight tolerance and they cannot get them new anymore, so maybe yours just unfortunately fell slightly outside this limit, Better the change them, rather than recon them just to fail down the line.

Cheers

Will 2005 90 XS
1954 86'' Series 1 tilt
1968 88” 2A 200tdi
2002 110 Hardtop

27th Nov 2024 10:14am

alexatnd

Member Since: 19 May 2015
Location: Yorkshire
Posts: 278

MadTom wrote:
You can connect injectors (old ones) without mounting them in the engine head, and then test them through diagnostics - ECU can click them. Do it more than once for all injectors and look for any faults in ECU.

What a good idea. This is tail end of a long battle.

Originally asked local garage to change injector seals on this engine ( never done it before) ... and all 6 rocker arm bolts sheared .... Had a spare td5 10p engine in garage ( as you do

) so they took the head, injectors and all off that and fitted it

Then had head gasket losing cooland issues so took original head to be skimmed and tested by machine shop in Castleford and fitted that with the (spare) set of injectors given the ECU was reprogrammed for them.

So ive got the original injectors on the shelf. As you suggested, I'll connect them up and see what LynxEvo thinks of them Santa - 1977 Series 3 - new chassis, tub, disc brakes,SU Carb
Gertie - 1999 110 TD5 - like a Phoenix from the ashes back on road... almost
Effie - 2004 110 TD5 County

27th Nov 2024 11:06am

alexatnd

Member Since: 19 May 2015
Location: Yorkshire
Posts: 278

derbywill wrote:
I was talking to an injector specialist who seemed pretty clued up on Td5 injectors and said the coil has a really tight tolerance and they cannot get them new anymore, so maybe yours just unfortunately fell slightly outside this limit, Better the change them, rather than recon them just to fail down the line.

Cheers

Will

Yeah, so they had a set of reconditioned injectors that i've bought ... as per other reply on this thread.Will test with old injectors 1st to check ECU

Was talking to someone from Alive Tuning yesterday who said that theyve never found anyone who can recondition td5 injectors successfuly and my best bet would be to just try and find a working set.
A Santa - 1977 Series 3 - new chassis, tub, disc brakes,SU Carb
Gertie - 1999 110 TD5 - like a Phoenix from the ashes back on road... almost
Effie - 2004 110 TD5 County

27th Nov 2024 11:12am

Chris86

Member Since: 15 Jul 2014
Location: South Yorks
Posts: 789

Td5 injectors

We went through 2 sets of reconditioned injectors not operating correctly before getting a set that were supplied via Landrover (from Britcar).

Chris

27th Nov 2024 11:56am

alexatnd

Member Since: 19 May 2015
Location: Yorkshire
Posts: 278

eek! hope not, the replacement ones i've jsut bought are expensive enough
A Santa - 1977 Series 3 - new chassis, tub, disc brakes,SU Carb
Gertie - 1999 110 TD5 - like a Phoenix from the ashes back on road... almost
Effie - 2004 110 TD5 County

27th Nov 2024 1:07pm

MadTom

Member Since: 10 Sep 2013
Location: Olomouc
Posts: 625

Tight tolerances of coil parameters? Do you know details, or it is just a way, how to tell custommer, that they don't know, what to do? During my attemps to repair TD5 ECUs I made full schematics ot the ECU itself and some tabletop tester to run the ECU outside of the car. Power switches (TOP and BOTTOM switch) are simple, sensing circuits around them, to controll the current through injectors not. I was testing ECU first with set of used injectors, but it was quite noisy and smells from diesel. So I made some coil to simulate coils in injectors to make ECU happy. It was like 10% around coil parameter of injectors, and ECU is happy now. So no strict parameter.
Reconditioning injectors is all about the high pressure parts - pump, nozzle and the rest between then. I have seen some bad after attemp to clean then, and some good remanufactured with factory new parts. I'm not sure, that these parts are still possible to buy.
For testing, there is no need to set up the injector codes in ECU. TD5 will run with any codes, probably just not as smooth as possible. For longer use, it is necessary ut use right ECU/software in ECU with right codes. With Nanocom it is possible to write the injector codes with running engine and see/hear/feel the change. "Drobek" = The Small One - Discovery 2, "Blufínek" = The Blue Thing - Defender 130, and for me at least Ford Mondeo

28th Nov 2024 6:43am

alexatnd

Member Since: 19 May 2015
Location: Yorkshire
Posts: 278

MadTom wrote:
You can connect injectors (old ones) without mounting them in the engine head, and then test them through diagnostics - ECU can click them. Do it more than once for all injectors and look for any faults in ECU.

So do i have to unplug the fuel pump relay as well? or just connect injectors to the loom ?
Am I not going to have diesel spraying when i turn ignition on ? Santa - 1977 Series 3 - new chassis, tub, disc brakes,SU Carb
Gertie - 1999 110 TD5 - like a Phoenix from the ashes back on road... almost
Effie - 2004 110 TD5 County

3rd Dec 2024 4:25pm

TexasRover

Member Since: 24 Nov 2022
Location: Paris
Posts: 1084

The electric pump is just to feed and provide some positive pressure. The injection pressure comes from the cam that acts on the injector plunger. Without a cam there is no pressure. Also the solenoid releases the injection pressure

3rd Dec 2024 5:05pm

derbywill

Member Since: 25 Mar 2010
Location: Derbyshire
Posts: 559

Yes take the fuel pump relay out, or the fuel pump will run in the tank and fill the bores up with diesel.

Cheers

Will 2005 90 XS
1954 86'' Series 1 tilt
1968 88” 2A 200tdi
2002 110 Hardtop

4th Dec 2024 7:38am

alexatnd

Member Since: 19 May 2015
Location: Yorkshire
Posts: 278

The joys of finding what relays do what in a defender. Gertie is a 1999 td5 110
piccies attached, 2 relays under drivers. seat, few behind gearstick, some people suggested might be the green one ... the again local land rover parts supplier said its the yellow relay under the seat ....

Click image to enlarge

Click image to enlarge

.... and its the green one. Unplugging the yellow one under the seat stops EMS,glowplug and charging light from apearing Santa - 1977 Series 3 - new chassis, tub, disc brakes,SU Carb
Gertie - 1999 110 TD5 - like a Phoenix from the ashes back on road... almost
Effie - 2004 110 TD5 County

Last edited by alexatnd on 9th Dec 2024 11:27am. Edited 2 times in total

4th Dec 2024 5:09pm

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