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Martin Tyas
Sr. Member
Posts: 278
Espace, because it's worth it!
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« Reply #32 on: April 13, 2007, 09:52:31 pm » |
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I hope your car will be as well as you seem to be! We are all happy you are here with us! Good of you to say so Anders.... I guess that I was just lucky to have a small brain in a big cavity so it would seem that little harm was done And the only indication that I had undergone any procedure was a very small scar where they went in to the femoral artery in my groin before using imaging systems to navigate their way up into my head from there. I was obviously out of it when they packed out the aneurysm with platinum coils but it was a bit disconcerting having them go back in to my head the same way a year later for a check up.... whilst I was awake Anyway... that's getting off topic. I had heard about Roy and his level of knowledge and expertise but hadn't contacted him. I'll try sending him an e-mail just to see if he has any previous experience of such a problem. thanks Martin
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1968 Cessna 182L Skylane 1991 BMW 520i SE Auto 2002 Grand Espace 2.2dCi "The Race" 2003 Astra 1.8i Cabriolet "Edition 100" 2011 Insignia SRi VX-Line Red 2011 Honda VT1300CX Fury
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Anders Dinsen
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« Reply #34 on: April 17, 2007, 02:40:28 pm » |
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Hi Martin Yes, Roy knows a lot about these cars and has both experience and knowledge to understand how and why components fail. He is quite gifted. I have also coupled his experience with my own garage's work with excellent results. The comment about the ECU needing to know what has changed is interesting. I am personally feeling that there is something we don't know since the ECU is not reporting a problem - yet, the car won't start. For some reason, the ECU is ignoing a condition that would normally result in a fault code being raised, but we don't have enough information to say what. It's good though that your garage seems to work systematically on the problem. My fingers are still crossed! - Anders
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1982 Talbot Matra Murena 2.2 prep 142 2017 BMW i3 "Charged Professional" 94Ah
Used to own: 2001 Renault Matra Grand Espace "The Race" V6 24v 1997 Renault Matra Espace 2.0 8V 1987 Renault Matra Espace J11 2.2
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Martin Tyas
Sr. Member
Posts: 278
Espace, because it's worth it!
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« Reply #39 on: April 18, 2007, 04:53:54 pm » |
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Before doing anything else this morning or making any decisions I first contacted Feather Diesel ( www.feather-diesel.co.uk) to find out what they would charge for supplying the components.... out of curiosity as much as anything else because unless there was an absolutely incredible difference in price I would let the Renault dealer supply and fit the parts.... because as much as I want to keep expenditure to a minimum I do not consider profit to be a dirty word and the dealer has to make some out of parts as well as the labour (not only to cover general overheads but also the costs for training & special service tools)... but secondly, at least with parts both supplied and fitted by the dealer there is some warranty / come-back on the job. Feather advise that they would first test the pump and injectors. The pump test would cost £157 and to test the 4 injectors would cost £110........... BUT...... to test the pump it still has to be removed so there is the cost of labour for doing that as well as for it's replacement, plus the pump to rail pipe, irrespective of whether the pump tested OK or not.... AND at less than £300 for a new pump from Renault they couldn't test and then refurbish the existing pump for less than it would cost to have brand new one. Regarding the injectors.... the test can only determine whether or not the injector is working satisfactorily but if it's not working the test will not determine if the problem is mechanical or electrical and whilst they can resolve a mechanical defect they cannot repair a solenoid problem. So by the time you take account of the labour to remove the injectors, the new high pressure pipes required when re-fitting them plus the cost of a test it's more economical simply to go ahead and fit a new No.4 Injector and pipe. They couldn't quote me exact prices for the pump or injectors because I didn't have either the Renault of Bosch part numbers and unfortunately the Bosch system didn't have the details even though I drilled down the system with him to get to a G9T 710 in a JE0K.... but he did say that the pump would be about £300 and the injectors over £200 each so pretty much in line with the prices quoted by the Renault dealer. Also, each injector is tested individually and data recorded that has to be programmed into the injection computer which then controls when and for how long the injector is opened using the individual parameters for each injector so Feathers may not have been able to do the job properly without the Renault diagnostic/computer box. As Roy pointed out in common rail diesels it's the injectors and the computer that does all the fuel metering and not the pump which simply delivers fuel under high pressure in to the rail. That's why, in relative terms the pump is quite low cost and the injectors expensive. I later spoke to the dealer again advising that I simply couldn't justify having a £2300 expenditure but would sanction them replacing No. 4 injector and pipe plus the pump and the pipe to the rail but asked them first to change the injector and then re-test the pressure using the diagnostic computer as well as trying an alternative pressure regulator as Roy had suggested. Roy's opinion was that the low pressure reading could have been partially if not fully down to the injector leak off. He also thought that at only 22bar pressure it was unlikley to start at all but would certainly run badly....which it didn't once it was running. However, they were adamant that the pump is goosed and cautioned me that if the pump was breaking up then there could be particles elsewhere in the fuel system that could ultimately end up in the other injectors or the new one. They think that it's a particle from the pump that found it's way in to No.4 injector to cause the leak off problem and the reason for there being essentially two problems occurring simultaneously. It's also why they wanted to change all 4 injectors so they could ensure a clean system. But I refused to have all 4 changed and instead asked them to save me the old pump so I could take it apart to help determine the extent of any risk I faced from further metalic particles. I'll keep you posted as to any developments. Martin
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1968 Cessna 182L Skylane 1991 BMW 520i SE Auto 2002 Grand Espace 2.2dCi "The Race" 2003 Astra 1.8i Cabriolet "Edition 100" 2011 Insignia SRi VX-Line Red 2011 Honda VT1300CX Fury
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Anders Dinsen
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« Reply #40 on: April 18, 2007, 09:06:42 pm » |
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Hi Martin
I picked my Bosch Automotive Handbook (try Googling for it) and turned to the "diesel-engine management" section to look at how the injectors and fuel pump works. I've never before bothered reading about it, but I must say that it's really an incredibly simple system. The computer software probably isn't, but the system as such is...
Anyway, it seems that there's no filter inside the injector - petrol injectors have a small filter fitted that can be exchanged. So if there's metal in the system then it may get stuck in the injector, preventing full closure, or damage the nozzle or needle, or any other component in the injector. The injector is made in such a way that the solenoid and return spring actually doesn't provide the full opening force - it is augmented by the hydraulic pressure in the system.
In other words, the leak-off test sounds to be the correct way of diagnosing an injector. But since the others are okay, why should they go wrong? Because they are old? Perhaps, but since they are far more expensive than spark plugs on a petrol engine, I still think it's a good idea to keep the others, and besides, I don't think they are much more difficult to replace than the heater plugs (I know they are a pain to remove).
There is a fuel pressure sensor fitted in the fuel rail - it's odd that the computer hasn't detected the low pressure?
I don't know how little pressure the system can work with, but I tend to agree with Roy that if the cranking pressure is as low as 22 bars, then the running pressure should also be very low, and then I don't understand why the computer has not detected this?
I think by the way, that the relatively low price of the pump is affected by the fact that there has been several failures reported of these. Bosch had lots of problems with these, and I think Bosch lost a good deal of money on the common rail diesel systems back around 2000. Then they have probably increased the price of the injectors... the price of those sounds a bit silly.
- Anders
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« Last Edit: April 18, 2007, 09:10:28 pm by Anders Dinsen »
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1982 Talbot Matra Murena 2.2 prep 142 2017 BMW i3 "Charged Professional" 94Ah
Used to own: 2001 Renault Matra Grand Espace "The Race" V6 24v 1997 Renault Matra Espace 2.0 8V 1987 Renault Matra Espace J11 2.2
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Martin Tyas
Sr. Member
Posts: 278
Espace, because it's worth it!
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« Reply #41 on: April 19, 2007, 07:11:52 pm » |
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I still think it's a good idea to keep the others, and besides, I don't think they are much more difficult to replace than the heater plugs (I know they are a pain to remove).
It's not necessarily the physical removal and replacement of the injectors that's the real problem Anders (although in the service bulletin covering the G9T engine in Lennart's vault it shows a special service tool) but it's the requirement for not only having access to but knowing how to use the Renault diagnostic and set up computer because each injector has it's own individual set of values that have to be programmed in to the injection computer. That is also why the suggestions, as good as they are, to obtain the parts from an accident damaged or scrapped vehicle cannot be practically pursued because I cannot realistically envisage a Renault dealer accepting to set up the computer after I've fitted second hand parts. And unless you could interrogate the computer of the car from which the injectors were removed how do you get the values that are required to be programmed in? Are these just advances in technology or part of a well executed plan by vehicle manufacturers to ensure that you go back to an authorised dealer for almost all service work? There is a fuel pressure sensor fitted in the fuel rail - it's odd that the computer hasn't detected the low pressure?
I don't know how little pressure the system can work with, but I tend to agree with Roy that if the cranking pressure is as low as 22 bars, then the running pressure should also be very low, and then I don't understand why the computer has not detected this?
The computer can detect this from the fuel pressure sensor but it doesn't come up as a warning on the dash. A dealer can get the pressure reading by interrogating the car's computer system using the diagnostic box which is where they came up with the 22 bar whilst cranking the engine over..... but until they do the leak off test they don't know exactly why the pressure is low or where the pressure is decaying. Just to give you a further update. I'd saved the filter that was fitted when the Espace had it's 72,000 mile service. So it has been on the vehicle for approx 3000 miles since the service and during the period when the starting problems manifested themselves. I had been wary of trying to open the sealed filter cannister in case I introduced contamination that would make it difficult to see if there was any pump debris but I took another look at it an decided to take a chance on trying to split it around the joint between the main body of the cannister and the cupped base. I ran a hacksaw all the way around but not all the way through the joint and then prised it open and withdrew the element from the body. There is no sign of any visible particles or debris trapped within the element but in the small amount of fuel residue that remained in the bowl I could see some minute particles... similar in size but not colour to the flecks in a metallic paint. However, these do not appear to be ferrous but more copper in colour as they glistened in the sunlight... so maybe phosphor-bronze from a pump shaft bushing rather than ferrous bits from the lobes of the pump vanes?. I phoned the dealership again this morning to check if the parts were available from Renault stock and when I was likely to get the car back. The pump will arrive Saturday and they will work on it during Monday and Tuesday. I spoke to a different guy in the service department and he was really trying hard to get me to replace all 4 injectors saying that if I only had one replaced then don't come back to them in 6 months when it's starting badly again and particles have got into the other injectors. He also mentioned the insurance jobs they do when people have put petrol instead of diesel in the tank and it has wrecked the pump. He was saying how they have to replace both pumps, all pipework, all the injectors and the fuel tank to make sure that there are no particles left in the system. So I simply said to him that he had just answered his own question as to why I would only have one injector changed.... what is the point of changing 3 good injectors if there is debris in the system because without a complete clean out of the system the debris could get into the injectors whether they are the old ones or new ones. "I see what you mean Mr Tyas" he replied!! I then went on to reiterate that the only way we will really know how bad or otherwise any contamination is likely to be is to strip the pump once it's removed. So they are giving me a call on Monday once the pump is off and we'll split it, see what damage there is and make a decision at that point as to how far we go or otherwise. Martin
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« Last Edit: April 20, 2007, 10:09:20 am by Martin Tyas »
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1968 Cessna 182L Skylane 1991 BMW 520i SE Auto 2002 Grand Espace 2.2dCi "The Race" 2003 Astra 1.8i Cabriolet "Edition 100" 2011 Insignia SRi VX-Line Red 2011 Honda VT1300CX Fury
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Anders Dinsen
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« Reply #42 on: April 20, 2007, 09:06:21 am » |
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Hi Martin
It's really good to hear that you've found a garage where they can actually communicate with their customers!
Yes, I think the injectors are precision devices - it probably doesn't take more than a few thousand nano-particles to change it's pattern a little with the pressure it is operating with, and further more, from how I understand the management system, it is running open-loop.
A (modern, my Murena doesn't!) petrol car uses an oxygen sensor to adjust the mixture, so a little difference between injectors doesn't matter much. From what I can read in the Bosch bible, there's no mixture sensing in the diesel common rail systems.
That means that the comptuer needs to know the opening times and flow numbers of the injectors - otherwise it will run the engine too lean or too rich.
The fuel filter is sitting before the pump, I would think that anything you were find in there would be coming from the tank and not the pump (if it's failing)?
But I really like your systematic approach to the problem!
- Anders
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1982 Talbot Matra Murena 2.2 prep 142 2017 BMW i3 "Charged Professional" 94Ah
Used to own: 2001 Renault Matra Grand Espace "The Race" V6 24v 1997 Renault Matra Espace 2.0 8V 1987 Renault Matra Espace J11 2.2
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Martin Tyas
Sr. Member
Posts: 278
Espace, because it's worth it!
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« Reply #43 on: April 20, 2007, 01:42:42 pm » |
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The fuel filter is sitting before the pump, I would think that anything you were find in there would be coming from the tank and not the pump (if it's failing)?
You are of course correct Anders.... however.... the fuel return lines, including the one returning unused fuel from the injectors go back to a manifold within the fuel filter housing before going back to tank via a heat exchanger to cool it down. So I thought it was worth checking whether the manifold in the filter housing was just used as a "junction box" for the return lines or if some of the returned fuel went through the filter housing before going back to tank.... in which case there could potentially have been some evidence of debris in the filter. Having opened up the fuel filter cannister I found that there is indeed a small (1.5mm) venturi within the return line manifold that allows some of the fuel back into filter housing. Whatever percentage of returned fuel goes into the filter housing through that venturi doesn't actually go back through the filter element but it does mean that debris from the pump (if indeed there was any) could possibly have found it's way into the filter housing and have settled in the bowl at the bottom. So it was maybe worth a look inside the filter as I wouldn't have wanted to risk re-using it anyway under the circumstances even though it had only been on the car for 3000 miles. Martin
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« Last Edit: April 22, 2007, 10:57:47 am by Martin Tyas »
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1968 Cessna 182L Skylane 1991 BMW 520i SE Auto 2002 Grand Espace 2.2dCi "The Race" 2003 Astra 1.8i Cabriolet "Edition 100" 2011 Insignia SRi VX-Line Red 2011 Honda VT1300CX Fury
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