Techbod Advice Please Its Back P1112

[coastline taxis]

this guy seems to know a lot about this engine and this is his answer and im leaning toward his answer ( copied from the picasso forum ) and injectors could be the problem.

how to make your own injector test kit.

 

http://images.google.co.uk/imgres?imgurl=h...l%3Den%26sa%3DN

 

canyondust Oct 28 2008, 01:18 AM Post #6

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Tank pump should produce 7-8Bar into the filter housing.

 

Preheat system I dont see has any great bearing on the current issue.

 

The high pressure fuel regulator wont cause the engine to 'run on' as in theory your injectors at key off should all be closed.

 

Monitoring the rail sensor (or from live data) during key on engine off, crank, idle, and say 2k may be worth doing out of interest to get some indication of the pump performance and possibly monitor the output pressure regulator.

 

The issue sounds like an injector problem rather than anything else. Ideally looking at what is known as injector adaptations (this is the amount of delivered fuel (in mm3/stroke) each injector has to be adjusted from the map data to produce the correct crank acceleration - or in other words correct combustion) and can be taken from the diagnostic port. This could give a quick a and clear indication of a faulty injector(s).

The leak back test is also very worth while and I would imagine most garages have the equipment - its essentilly 4 small bottle with tubes on that are connected to the leak back port on the injectors (so the normal black pipes are removed) - and the amount of fuel leaking back in a given time is measured and the balance observed.

 

Also measuing the capacitance of each individual injector solenoid is another very worth while, yet quick and easy measurement. This will give a very good confidence check of the condition of the Piezo Electric solenoids.

 

I would be amazed if it will fire at only 100Bar, I would like to see from a good pump around 200Bar after 1.5 to 2 revolutions and for it to sit nicely at 297Bar at idle.

 

So to sum up - ensure adequate rail pressures, pressure regulator performance (open close ratio OCR), Injector Adaptiations, Leak Back, solenoid capactiance.

 

I would hope from that the fault would be quickly diagnosed.

 

Regards

 

James.

HORRRAAAY HORRRAAAY the c5 just ran all day but i dont want to speak to soon. Went on a course for the canbus and ecu systems on tuesday and the guy that was speaking to us is one of the top men in the country. so at the end when he asked if we had any questions so i was off like a rocket to the front and explained about p1138 anyway he stopped me and told me that the fault was down to 1 of 2 things either the injectors or a bio metal strip that the early c5s had in the fuel filter housing anyway straight into the garage and swapped injectors over car ran 2 hour and ping back it came p1138. So next we changed the fuel filter housing and the car has now been on the road working for 2 days so heres hoping. Out of curiosity does anyone know what this bio metal strip is and does as ive never heard of it

[paul.h]

Could the bio metal strip be anything to do with water detection in the fuel filter ? Does it join up to the electrical connector on the bottom of the filter ?

[coastline taxis]

Could the bio metal strip be anything to do with water detection in the fuel filter ? Does it join up to the electrical connector on the bottom of the filter ?

nope no electrics to the fuel housing at all. we pulled the old housing to bits today and just couldnt see anything at all. Ive tried searching the net and nothing at all just know that the car is fine now so he was right

[techbod]

the bio metal strip is a heater element so expands when hot a bit like the thermostat none electronics but coolant temp controlled but still has that domino effect and that's why you get that fault code so if it didn't do its job it would shut the fuel off, never thought of that but its logged in the gray matter now for future reference :blink:

[paul.h]

In the RTA manual there is a cross section of a Bosch fuel filter which if I have got the translations right - shows the feed from the low pressure pump going in to the side of the filter casing to a (element thermodilatable) bi metal strip (?) which either directs the fuel down to a lower connection and out to a (boitier thermostatique) heating box (?) or up to the filter proper. The return from the heating box is at the bottom of the filter. The fuel goes through the filter cartridge from the outside to the inside and inside is a pressure regulator which either directs the flow to the high pressure pump or back to the fuel tank, through the top connections. It does not show the water detection which is on some other pictures.

 

There appears to have been a change of filter types, up to model OPR no 8936 it was a Bosch and from model 8937 it was a Mahle. In the Bosch filter the fuel heater is separate to the filter but in the Mahle filter it is part of the filter and has a 12v supply. This is providing my translations are about right.

 

The above may make sense to Coastline having now seen the insides of a filter.

[techbod]

I know what your saying but the bimetal strips isn't electonicly resultant to the ECU but will throw codes as should be expected when it fails

[paul.h]

Additional thoughts:- Whilst previously being fixed, the fuel filter will have warmed up (and bi-metal strip thus moving to direct the flow to the cartridge and not the heater - may be able to see the end of the strip by looking into the fuel inlet nozzle) allowing the car to run when the code was reset. The length of time between the apparent fixes and the fault re-occurring could be explained by the time it has taken the filter to cool back down again after warming up in the garage. If used on a warm day and the fuel in the tank had also warmed up then this could take a while - but if all is cold then just a few minutes. Maybe a way to test for this fault would be to warm the filter with a hair drier, reset the code and see if it runs. If Coastline had not been on the training course and learnt of this fault then it could have been next summer before the car ran again.

[techbod]

in theory you are right that's if you could see the bi-metal strip which I doubt "same as the thermostat you know its there but you have to remove it and test it to see if it works" apart thom the obvious problems it causes when it doesn't work :blink:

[coastline taxis]

in theory you are right that's if you could see the bi-metal strip which I doubt "same as the thermostat you know its there but you have to remove it and test it to see if it works" apart thom the obvious problems it causes when it doesn't work ;)

Took a grinder to the old filter housing today and found the strip its right at the bottom of the filter. Parts of it had been worn away probally with the diesel flowing past it. And i can honestly say that we wouldnt of found fault as our line of thinking didnt include the filter housing. Car is still running perfect so its sorted

[techbod]

now you will have to think in a different way and my self as it never occurred to me this would cause something like this