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Head gasket saga begun .!!

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Tjensen   
Sun Apr 12 2020, 12:46pm

Joined: Jul 17 2012
Member No: #954
Location: Bergen
Loose gasket on one injector: leaking diesel down to warm areas of engine, then start to smoke. I had this problem. Easy to fix (for the garage)
sidenham   
Sun Apr 12 2020, 08:42pm

Joined: Jul 23 2019
Member No: #3993
Location: St Marys Bay, Kent.
Loose gasket on one injector: leaking diesel down to warm areas of engine, then start to smoke. I had this problem. Easy to fix (for the garage)


Tjensen. Thanks for the imput, but not sure what gasket you're talking about, On the 2.7 injectors the only seal is a copper washer and there all brand new torx down correctly with no leaks to the pipework.
sidenham   
Tue Apr 21 2020, 09:41pm

Joined: Jul 23 2019
Member No: #3993
Location: St Marys Bay, Kent.
It's a sad sad day but I have to announce the end of this Saga. My problematical big girl has succumbed, she's given in, and allowed me to FINISH her.

I've worked on some of the greatest cars ever built, be it repairing or re-building Classics such as MK2s Triumph Stags and the like. But this engine, replacing both cylinder heads in situ that's without taking the engine out has been an experience. But doing it on my driveway outside the garage because it's too big to go in and shut the doors, during this winter, on the windswept coast. !!

Was a Nightmare. The last things needed to end the smoking fuel problem was 3 refurbed injectors. She was taken around for the roadworthiness MOT and sailed it with just a couple of advisories.

Basic stuff to do, but she sounds and runs " Silently". She's had a complete polishing and is fabulous. I'll add a few pic's soon for your appro.
sidenham   
Sat May 16 2020, 09:27am

Joined: Jul 23 2019
Member No: #3993
Location: St Marys Bay, Kent.
Here we go again !!!! , My big girl has decided that I haven't done enough, fuel wise. I changed the injectors return pipe (bleed off) for a Jaguar/rover one but one of the O rings was weak and started to leak. SO changed that for a repaired old one of mine (Pipework) all good bled and no leaks with plenty of pressure. Turn her over nothing, spins well had no problems before changing this pipework all electrical connections looking as they should. I think it's an electrical problem because the fuel is there but just won't fire. Any ideas what could be happening or not happening.
Trainman   
Sun May 17 2020, 10:37am


Joined: Apr 12 2010
Member No: #86
Location: Penwortham
I’ve had something like this before....... probably not the same thing.......but.....

If the car has had the battery disconnected then try to lock it and unlock it, if you don’t the immobiliser kick in.......

Sorry if it sounds like a baby step...... just a thought
sidenham   
Sun May 17 2020, 11:59am

Joined: Jul 23 2019
Member No: #3993
Location: St Marys Bay, Kent.
Umm, Thanks Steve I'll keep that in mind. I'm in the middle of changing the high-pressure switch in the fuel rail. And drying out all the wiring around the H/P fuel pump area, diesel oil everywhere again. My grandson turned the ignition on whilst I was in the middle of removing stuff. opps.


Just checked my fault codes and there it is P1164 which relates to fuel pressure switch in H/P rail above h/p fuel pump. Had a look at the pumps belt just to see if it was still in it little tensioned state, and it seems fine.

On the C6, if the pressure is not high enough will the ECU send or not send a signal to the fuel injectors to open as required. And should the Fuel pressure be good and the switch be operating correctly what else would stop the injectors from opening?.
sidenham   
Wed Jul 01 2020, 04:59pm

Joined: Jul 23 2019
Member No: #3993
Location: St Marys Bay, Kent.
MORE PROBLEMS. I've now got p0193 and she shut down.

I'd come back from a trip to relatives in london, the next morning went out to start her and she started misfiring badly. Touched the cables going to the high pressure fuel switch/hp pump solenoid and she stopped and that was that.

What I've done so far is replaced the high pressure fuel switch/ the high pressure fuel pump/ fuel filter and checked all the connectors are in ok condition. Fuel from tank pump is fine but no pressure from high pressure pump, think solenoid is not opening.

Cables all seem to be sound except I cannot get a reading from the solenoid 12v back to the ecu, ignition on. The pressure switch wires , orange/green/blue all show a circ no matter which wire is tested same for the wiring to the filter connector. Thats orange to blue green to blue or orange to green. I'm stumped.

Is there anyway to check if these wires are doing the things they are supposed to do OR is there a Auto Elect mechanic out there that can help trace this fault for me LOCAL. Can't get anyone local it seems to come out to me, St Marys Bay Area, east coast kent. It can't be much but I'm not up to diesel electrics.

.
C6Dave   
Wed Jul 01 2020, 06:39pm


Joined: Oct 01 2009
Member No: #1
Location: Northumberland
Have you changed the High Pressure Fuel Sensor?

Found some Tech Docs showing the location - Click Here -

Having said that, fuel filter itself is a common problem.
Website
sidenham   
Thu Jul 02 2020, 10:15am

Joined: Jul 23 2019
Member No: #3993
Location: St Marys Bay, Kent.
Hi Dave , Yea I;ve replaced the hp fuel pressure sensor the fuel filter, fitted a new hp fuel pump, checked that the tank pump is delivering sufficient fuel so problem not there. Pulling of the pressure sensor plug and the same coloured wired plug on the fuel filter canister, no matter which wires are connector to a multi-meter, Ohms setting, an open circuit is present.

If this is controlled by a relay or is it direct from an ECU, not so easy to see on the wiring plans. Would love to know if a relay fault would cause this sort of ohms reading.

Another thing is that if the solenoid on the hp/pump is not opening to allow fuel to be compressed would that account for no fuel at the injectors. Very confused with the wiring on the fuelling side of this car. Might add that this is the third fuel sensor fitted but this last one is the real thing not chinese. For hig pressure pump solenoid read Regulator.
MGmike   
Thu Jul 02 2020, 12:09pm

Joined: May 21 2017
Member No: #3151
Location: South Queensferry
Dave the wiring diagrams are a bit of a challenge to read but be methodical and you should get there!

It looks like to HP pump solenoid and sensor is fed 12v from F5 in the engine bay which is in turn fed by a relay R2 in the same box. The rail pressure sensor looks a bit different with all cables going to the ECU. I would suggest you check for the presence of 12v at the two HP pump connectors and see where it takes you.
sidenham   
Thu Jul 02 2020, 04:30pm

Joined: Jul 23 2019
Member No: #3993
Location: St Marys Bay, Kent.
Hi Mike, Just checked and both hp pump plugs are showing 12v down to ground. I'm getting with ignition off an open circuit on all 3 wires with multimeter conected to 1-2, 2-3, 1-3, 2-3. The same apply to the 3 wires on the filter housing plug. If this is happening would you say the ECU has a fault , and if so would it not show a code relating to it.

The only code coming up is p0193 but it's a new good one. If diesel fuel was in the harness or the pressure sensor plug would that cause this problem.
C6Dave   
Thu Jul 02 2020, 05:51pm


Joined: Oct 01 2009
Member No: #1
Location: Northumberland
sidenham wrote ...

The only code coming up is p0193 but it's a new good one. If diesel fuel was in the harness or the pressure sensor plug would that cause this problem.

P0193 points to the HP Fuel Sensor or the wiring harness so if your 100% convinced the sensor is OK then yes it could be a wiring /connector issue.

However the Tech Doc say's the pressure is reading to high, not low


Website
MGmike   
Thu Jul 02 2020, 07:45pm

Joined: May 21 2017
Member No: #3151
Location: South Queensferry
sidenham wrote ...

Hi Mike, Just checked and both hp pump plugs are showing 12v down to ground. I'm getting with ignition off an open circuit on all 3 wires with multimeter conected to 1-2, 2-3, 1-3, 2-3. The same apply to the 3 wires on the filter housing plug. If this is happening would you say the ECU has a fault , and if so would it not show a code relating to it.

The only code coming up is p0193 but it's a new good one. If diesel fuel was in the harness or the pressure sensor plug would that cause this problem.


Are you talking about the three wires on the pressure sensor?
You can't measure resistance between the wires as they go directly to the ECU and in to the electronics which is unlikely to have any direct connection between them. Same applies for the filter wires.

You need to check continuity end to end of each cable e.g from the sensor to the ECU.

Having looked again as the diag's the sensor has a supply on pin 3, an earth (2) and a signal (1). The supply is probably 5v and perhaps you can check that with the ignition on? If that's okay check the continuity of the cable from pin 2.


sidenham   
Fri Jul 03 2020, 11:32am

Joined: Jul 23 2019
Member No: #3993
Location: St Marys Bay, Kent.
Mike thanks for all of that, good of you to take that much time on this for me. I've checked the voltage from the supply pin 3 ignition on it's 5v continuity from pin 2 ignition on to earth good. but signal wire 1 to earth shows 5v as well, is that correct. Souldn't that be dead without any pressure of fuel activating it.
MGmike   
Fri Jul 03 2020, 11:46am

Joined: May 21 2017
Member No: #3151
Location: South Queensferry
No prob's I quite like trawling throught wiring diagrams (sad I know)..

What you're getting fits with the p0193 from the info Dave gives above and suggests a faulty sensor! But is it.....

If the sensor is working then Pin 1 should not go higher than 3.16v for more than a few seconds. I'm guessing it tells the ECU to trigger the bleed off solenoid on the HP pump when the pressure is too high.

Test it again after removing the sensor from the rail. If the voltage drops it's not the sensor (Guessing it should drop to something like 2.5v)
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