TD4 cold starting problem - senior help pls!

Hi,

Just moved to South Africa from the UK, I bought a 2002 Freelander TD4 as a run around even though I was warned not too by many people - I should have listened. I have experienced a raft of problem which have all been solved with my own knowledge base, I won't bore you with these tonight, however the final one is causing me serious mental strain. Tomorrow I will be John Cleese with a stick giving the car a whipping if you cannot help

I bought the TD4 as I am very familiar with the M47 engine having owned an MG ZT CDTi and tuned it well! I thought I could fix all issues on diesels having rebuilt vintage Lister diesels and having automotive electronics experience along with intermediate knowledge on common rail diesels.

The problem....

The car requires "winding up to start" when cold (20+ centigrade so not glow plugs!) this consists of some 5-7 seconds of cranking before it "catches", across all 4 cylinders.

In the first week the in tank pump became noisy and failed, the car had been difficult to start and I assumed this was the problem. After being quoted £450 by the independent Landrover dealer I bought an aftermarket unit from the UK and imported via UPS and fitted it yesterday thinking it would fix the problem.

This morning I went to start it and the same symptoms presented themselves 5-7 seconds cranking. When warm the car starts without issue but degrades the colder it gets. I therefore went through the usual suspects as follows:-

Bought a new battery just in case as the other one failed after <1 minutes cranking when testing

Checked wiring between HP fuel pressure sensor and ECU pin to pin - no resistance.

Checked HP fuel pressure (as stated on this forum)

"Connect multimeter between battery neg and blue/black cable (connector clean and pushed firmly onto HP sensor, you will have to probe into the connector)

Ign on (position 2) 0.5v approx
Engine idling 1.3v approx
3000 rpm 2.0v approx "

My results Ignition on 0.5V - Idling 1.3V spot on to the above results!

So I thought maybe low HP pressure when cranking, no problem here - with the cam sensor disconnected and cranking I got 1.3V indicating no injector leak back and no problem with the HP or LP pumps.

The car has done 122,000 Km's (76,000 miles) and has full Landrover service history. Performance is fine and no apparent burning of oil so I cannot believe its low compression but remain open minded.

I guess I could take it to the local "stealers" and put it on the testbook but I am not sure this would tell me anything (standard eobd reports no codes)

So please save a Freelander from a whipping and help me out!

Thanks in advance....

Were your voltages at cranking instant or after a period of cranking, ie 5-7 seconds? Have you confirmed both Lp pumps are running and checked LP sensor volts....

Low pressure sensor (located top of fuel filter housing) voltmeter connected between battery earth and green cable:

Ign ‘on’ and both pumps heard priming- 3.9 to 4volts.
Engine running both at idle and up to 3000rpm- 4 to 4.1volts.

I assume you have eliminated a restriction at the fuel filter although you would expect it to show at high rpm also.

Is it smoky at start up? I know the miles are relatively low but wondering if poor injector spray pattern/atomisation is the cause. You could always try some injector cleaner in the tank for a few fill ups. Forte diesel system treatment or Millers are both recommended on here, otherwise it's injectors out for testing.

Hi Chaser,

Thanks for the response.

In answer to your questions:-

-The HP voltage is pretty instant within 1 second of cranking.

-Unfortunately the wrong filter was sent from the UK, but as you say no lack of performance (and service 2000kms ago)

-Did not know which wire to test LP voltage so thanks, will test in the morning

I did consider IAT out of calibration and under fuelling engine when cold?

Whatever happens if I find the solution will feed back as I have found a number of posts similar to mine without a resolution being posted.

faulty injector leaking back ?

Optimus Prime said:

faulty injector leaking back ?

Click to expand...

Exactly where I would start looking but he seems happy that the HP sensor volts at ignition rule this out. Could always double check via the leak off pipes though. LP sensor volts could possibly give better a indication.

Thanks for the ongoing ideas...

Just an update for you. The LP voltage on G/W wire into the ECU is 4.3V when ignition is turned on (very quickly). As stated the HP pressure is 1.4V on cranking and always starts on the nail when warm/hot so I am ruling out injector leak back for the moment.

In regard to the IAT I disconnected the MAF (which incorporates the IAT) and it may be co-incidence but it started on within 2 seconds from cold (18 centigrade in Durban this morning). This idea was given to me by Ron who makes the Synergy unit for the M47, he states that the ECU defaults fuelling as if the outside temp is 0 Centigrade.

I am coming to the conclusion that maybe the M47 does use heater plugs above 5 centigrade. I am having great difficulty identifying wiring to and from the heater plugs, in addition the specific relay. I have found the enclosed text from another web posting, I guess I could download the Rave CD but this would be costly and slow here in SA so any upfront help would be appreciated.

In regard to the text below I have found fuse 6 (100A) and I guess what must be the relay (it is marked SM on the fuse cover and is yellow) and sits directly in front of fuse 6. The issue I have is that I cannot find the wiring to glow plugs without removing the inlet manifold, even though I have tested all wiring under the ECU cover and cannot find contact with multimeter between the othrside of the relay and glowplug wiring. Interesting though I can find four wires as stated in the text below but no connectivity between the four wires and relay. Maybe I have the wrong relay? Even if its not the heater plugs I would like to exclude operation of them during this "fix", apparently disconnecting the coolant sensor forces the ecu to activate them, the issue is I cannot find the coolant sensor!

"
DESCRIPTION AND OPERATION
CHARGING AND STARTING – Td4 DESCRIPTION

Starting
The starting system on the vehicle comprises a 12 volt starter motor which drives the engine to start the combustion process. The starter converts electrical energy into mechanical power. The vehicle electrical system must be capable of supplying sufficient power to enable the engine to be cranked.

Charging
The charging system comprises a battery and an alternator. The battery must be of a sufficient capacity to operate the starter motor and operate various electrical systems in the vehicle. The alternator charges the battery when the engine is running and increases its output as demand on the battery increases.

The instrument pack incorporates a charge warning lamp which illuminates when there is no output or a low output from the alternator. For a detailed description of the charging and starting system, refer to the Engine Management Systems – EDC section of the System Description and Operation Workshop manual.

OPERATION

General
Feed from the positive battery terminal (C0192) is supplied to the main relay, fusible link 1, fusible link 3, fusible link 6, and fuse 10 (C0632) on an R wire. All are located in the engine compartment fuse box. The battery (C0192) also supplies a constant feed to the starter motor solenoid (C0631) on an R wire.

Fusible link 1 is connected in series with fusible link 7, which is also located in the engine compartment fuse box.
Fusible link 3 (C0571) is connected to the ignition switch (C0028) by an N wire. When the ignition switch is turned to the 'ignition' position, current flows across the switch (C0028) to fuse 6, fuse 8, and fuse 19 of the passenger compartment fuse box (C0588) on a G wire.

When the ignition switch is turned to the 'crank' position, current flows across the switch (C0028) to fuse 5 of the passenger compartment fuse box (C0588) on a WR wire.

Starting
Main Relay
The earth path for the main relay coil (C0576) is controlled by the Engine Control Module (ECM) (C0603) on a WK wire. The energised main relay provides a feed to fuse 1 which is also located in the engine compartment fuse box. Fuse 1 (C0576) provides a feed to the glow plug relay (C0215) on an RW wire.

For a detailed description of main relay operation, refer to the Engine Management Systems – EDC section of the System Description and Operation Workshop manual.

Inertia Switch
Fuse 10 of the engine compartment fuse box (C0575) provides a constant battery feed to the inertia switch C0123) on a G wire. The inertia switch is a normally closed switch. If the inertia switch hasn't been tripped, current flows across the switch (C0123) to the fuel pump relay coil (C0730) on a GU wire.

The inertia switch (C0123) also provides a feed to the Central Control Unit (CCU) (C0428) on a GU wire. For more information on the CCU, refer to the Control Units section of the Workshop manual, and the Anti-theft Alarm and Central Door Locking (CDL) section of this manual.
+ANTI-THEFT ALARM AND CENTRAL DOOR LOCKING (CDL).

Fuel Pump Relay
The fuel pump relay coil (C0730) receives a feed from the inertia switch (C0123) on a GU wire. The earth path for the relay coil (C0730) is controlled by the ECM (C0331) on a BP wire. The energised fuel pump relay enables a feed from fuse 10 of the engine compartment fuse box (C0575) to flow across the relay switch contacts to the tank mounted fuel pump (C0114) and the secondary fuel pump (C0205) on WP wires. Both pumps are earthed on B wires.

Glow Plug Relay
Fuse 6 of the passenger compartment fuse box (C0581) provides an ignition feed to the ECM (C0603) on a W wire. If all criteria are met, the ECM (C0606) provides an earth path for the glow plug relay coil (C0215) on a BR wire.
Fusible link 6 of the engine compartment fuse box (C0577) provides a constant battery feed to the glow plug relay switch (C0215) on an NW wire.

When the relay is energised, the switch contacts close, allowing the glow plug relay to provide a feed to the following:

To glow plug number 1 (C0476) on a BG wire.
To glow plug number 2 (C0477) on a BP wire.
To glow plug number 3 (C0478) on a BY wire.
To glow plug number 4 (C0479) on a BR wire.

Starter Relay
Fuse 5 of the passenger compartment fuse box (C0581) provides an ignition switch 'crank' feed to the immobilisation ECU (C0059) on a WR wire. If the vehicle has been successfully re-mobilised, the immobilisation ECU (C0059) provides a feed to the starter relay coil (C0576) on an RW wire. The starter relay is located in the engine compartment fuse box, and is earthed (C0576) on a B wire.

A battery feed from fusible link 7 is now able to flow across the starter relay switch contacts (C0572) to the starter motor solenoid (C0178) on an NR then B wire. For a detailed description of the immobilisation ECU, refer to the Engine Immobilisation section of this manual.
+ENGINE IMMOBILISATION.

Starter Motor and Starter Motor Solenoid
The starter motor solenoid coil (C0178) receives a feed from the energised starter motor relay (C0572) on an NR then B wire (see above). The energised starter motor solenoid allows a battery feed (C0178) to flow across the switch contacts and power the starter motor.

Central Control Unit (CCU)
The CCU (C0428) receives a feed from the inertia switch (C0123) on a GU wire. If this feed is removed due to the inertia switch being tripped, the CCU will unlock all of the doors. For more details of CCU operation, refer to the Control Units section of the Workshop manual.

For more details of the Central Door Locking (CDL) system, refer to the Anti-theft Alarm and Central Door Locking (CDL) section of this manual. +ANTI-THEFT ALARM AND CENTRAL DOOR LOCKING (CDL).

NOTE: The CCU will only unlock all doors if the ignition switch is in the 'ignition' position. The CCU (C0429) also provides a signal feed to the immobilisation ECU (C0059) on a KN wire. This signal feed informs the immobilisation ECU to energise the starter relay. For a detailed description of the immobilisation ECU, refer to the Engine Immobilisation section of this manual.

END"

It's not easy to agree with your glow plug theory given that you say it's 18degC.

Disconnecting the IAT defaults to -5 so will increase fuelling whether you have a fault or not. It would be better to connect to diagnostic equipment and read live data.

Glow plug relay is in the e-box. Check fuse 1 engine comp fuse box.

ECT sensor is under the inlet manifold by no.4 glowplug.


IAT sensor resistances....

Temperature, °C. Resistance, k ohm

-20 (-4) 13.850
-10 (14) 8.609
0 (32) 5.499
10 (50) 3.604
20 (68) .420
30 (86) 1.662
40 (104) 1.166

The car requires "winding up to start" when cold (20+ centigrade so not glow plugs!) this consists of some 5-7 seconds of cranking before it "catches", across all 4 cylinders

Observe the exhaust tailpipe whilst an assistant cranks the engine from cold: No smoke at all until the engine actually starts would suggest LP/ HP fuel supply or injector problems. White smoke which actually smells of diesel would suggest a glow-plug problem but is unlikely at those ambient temperatures. D..

Thanks for all the input from you all..

So lets bring you up to date. Some very strange results.

Found the glow plug relay and wiring checked for resistance across the glow plugs. No resistance at all showing all are likely to be U/S and will require replacement.

Volt meter across relay coil no volts with ignition on showing no preheat of glow plugs. Connected diagnostics and checked live ECT and IAT data both within 1 degree of each other (20 centigrade), MAF around 25 at idle..

Started engine and I was stunned as the glow plug relay immediately activated for between 2-3 minutes (even though no glow plugs work!). So its strange that it post heats but not pre-heats.

Checked for injector leak back to be on the safe side had maybe 3 drops after 15 seconds total cranking.

Unfortunately I cannot get to the ECT to simulate a cold day without cutting the ECM wiring as I cannot find it, I guess its a manifold off job?

So in summary all parameters within spec, even if I change the heater plugs it wont pre-heat and change the starting issue. No bl**dy use them coming on afterwards. So I am still not sure if they should or should not come on at temperatures above 5 centigrade. So I guess its a couple of cans of Forte in the hope it cleans the injectors/rings maybe and that the glow plug operation is correct unless you guy's have a brain wave!

Thanks for your ongoing input and help.

So nothings changed car still needs winding up 5-10 seconds to start at 18 centigrade.

Everything double checked.

LP 4.3 volts (=36psi/2.5 Bar)
HP on cranking (immediately) 1.3V
Double checked injector leak back (all 4 ) both static and engine running no visible leak back.

I have also had it (provisionally) confirmed that heater plugs on common rail generally only operate above 5 degrees but come on post starting (for 90 seconds or so) for emission purposes (mine are shot and due to be replaced shortly but relay only operates post heat after engine start).

I had the compression checked today by means of battery cranking amps on Bosch diagnostics so I hope someone can translate the output for me?

The compression units used on the (Bosch) graph varied between 94 and 112, the workshop said the units were BAR however this would mean around 1500 PSI? Hmm I think not, it cannot relate to PSI as it would not start at those pressures . The battery cranking was minimum around 140 amps and the maximum (compression) varied between 250 and 265 amps.

Th workshop Manager said this was fine but I do not know how you relate this to PSI or CR of 18:1 any ideas.

Thanks in advance..

Well I must admit I never believed in magic potions but...they work!!

After 6 weeks of analysing this (see posting) problem a simple solution appears to have been found. After taking advice from united diesels in the UK I was advised to change the injector nozzles as they can stick. I therefore have purchased 4 injector nozzles which are currently on their way to SA in my daughters baggage. I was also advised three weeks ago to use Forte advance diesel injector cleaner. I met the representative out here talked through the problem and he kindly gave me 2x300ml bottles, the first I added to the tank when 1/4 full this made little or no difference, however he did advise me to carry out a shock treatment (which I delayed as I had ordered the new nozzles) in the following manner.

Remove fuel filter and diesel within, fill fuel filter with the Forte solution replace let pump run for 20 seconds start engine and let idle for 5 minutes to let solution hit the pump and injectors. Leave overnight and drive normally the next day.

So next day started the car which still had difficult starting, however the following day (and subsequent two days) it has started on the button.

So magic potions do work lets see if the problem returns, if so at least i will have new injector nozzles to fit!