Thats interesting Martin, I can't find any circumstances on mine where the electric pump will cut out with the engine running. Makes me wonder if either mine has a different setup or perhaps my low pressure pump is getting weak!Pleiades wrote: After the spheres I had a play with the ignition and pump thingy, the proccess seems to go like this.
Turn on the ignition and the pump will buzz for about 3 secs, or untill it has built up full pressure to the filter, when the engine starts, the pump will start running again to keep the pressure up to the main high pressure pump, this electric pump will keep on cutting in and out whilst the car is running just to keep pressure up, BUT, if you dissconect the electric pump whilst the engine is running, it will keep on going.
xsara high pressure pump
Moderator: RichardW
If the pump is cuting in & out while the engine is running then the only possibility here is that either the pump is faulty or it's wiring.nick wrote:Thats interesting Martin, I can't find any circumstances on mine where the electric pump will cut out with the engine running. Makes me wonder if either mine has a different setup or perhaps my low pressure pump is getting weak!Pleiades wrote: After the spheres I had a play with the ignition and pump thingy, the proccess seems to go like this.
Turn on the ignition and the pump will buzz for about 3 secs, or untill it has built up full pressure to the filter, when the engine starts, the pump will start running again to keep the pressure up to the main high pressure pump, this electric pump will keep on cutting in and out whilst the car is running just to keep pressure up, BUT, if you dissconect the electric pump whilst the engine is running, it will keep on going.
The pump should run at all times while the engine is running.
It would also be impossible for it to cut in & out as the fuel pump feed comes from the second side of the double relay and on the same output is the feeds to the airflow meter, clutch switch, turbo electrovalve & egr electrovalve. So cutting power to the LP pump would also cut the power to these items.
As for the engine continuing to run when the pump is disconected, i have never tried it so i cant say for sure but i was wondering how long you left it disconected for ? maybe it just needs to use the fuel left in the pipes ?
It seems strange that they would also fit the inertia switch to this same circuit if cutting power to the fuel pump circuit does not cause the engine to cut out.
I have been watching this thread with interest. The HDI fuel system is a box of tricks, and any practical information about weaknesses is handy in case of problems.
I have checked, and the engine of my 2001 Xantia HDI stops immediately if the plug to the tank unit is disconnected.
There is plenty of information about the DW10 Bosch EDC15C2 system on the web at
http://www.christiantena.pwp.blueyonder ... operation/
It is more or less the same information as in Revue Technique for the Xantia HDI. Here is a summary of the fuel system description.
The fuel delivery system consists of the submerged lift pump in the tank, the filter unit which also contains a diverter to heat the fuel at low temperatures (heater coil in thermostat casting), the high pressure pump, common rail and electronically controlled injectors, and a fuel cooler underneath the car in the return line to the tank.
The lift pump is an eccentric (constant displacement) roller impeller driven by a DC motor, all submerged in the tank. There is a relief valve set to 7 bar, and the working output pressure is in the range 2 to 3 bar. There is also a 300 micron (coarse) filter.
The filter unit consists of the element (5 micron), a bimetal diverter, and a pressure control valve. Below 15C, all the fuel goes via the heater coil in the thermostat housing, 15C to 25C progressively less, and above 25C none. The pressure relief valve shunts excess fuel back to tank. Output pressure to the HP pump after the filter is 1 to 1.5 bar. Presumably the pressure drop through the filter is quite high.
The cam belt driven high pressure pump is only a source of pressure, and has no part in timing the fuel injection. It produces 200 bar within 1.5 crankshaft revs, and a maximum pressure of 1350 bar. Absorbed power is 3.5KW maximum (getting on for 5 bhp – cam belt needs to be OK!). A minimum of 0.8 bar is required before fuel passes to the pump high pressure stage. Surplus fuel joins the filter bypass, and flows back to the tank via a cooler unit under the floor.
According to this description, the lift pump runs all the time the engine is running. Also, if it is correct that the HP pump needs 0.8 bar before it kicks in, the engine might not start if the lift pump is on the blink, or the filter blocked. Immediately the engine starts, the battery voltage will rise a volt or two, which might get things going, at least for a week or so.
Fred
I have checked, and the engine of my 2001 Xantia HDI stops immediately if the plug to the tank unit is disconnected.
There is plenty of information about the DW10 Bosch EDC15C2 system on the web at
http://www.christiantena.pwp.blueyonder ... operation/
It is more or less the same information as in Revue Technique for the Xantia HDI. Here is a summary of the fuel system description.
The fuel delivery system consists of the submerged lift pump in the tank, the filter unit which also contains a diverter to heat the fuel at low temperatures (heater coil in thermostat casting), the high pressure pump, common rail and electronically controlled injectors, and a fuel cooler underneath the car in the return line to the tank.
The lift pump is an eccentric (constant displacement) roller impeller driven by a DC motor, all submerged in the tank. There is a relief valve set to 7 bar, and the working output pressure is in the range 2 to 3 bar. There is also a 300 micron (coarse) filter.
The filter unit consists of the element (5 micron), a bimetal diverter, and a pressure control valve. Below 15C, all the fuel goes via the heater coil in the thermostat housing, 15C to 25C progressively less, and above 25C none. The pressure relief valve shunts excess fuel back to tank. Output pressure to the HP pump after the filter is 1 to 1.5 bar. Presumably the pressure drop through the filter is quite high.
The cam belt driven high pressure pump is only a source of pressure, and has no part in timing the fuel injection. It produces 200 bar within 1.5 crankshaft revs, and a maximum pressure of 1350 bar. Absorbed power is 3.5KW maximum (getting on for 5 bhp – cam belt needs to be OK!). A minimum of 0.8 bar is required before fuel passes to the pump high pressure stage. Surplus fuel joins the filter bypass, and flows back to the tank via a cooler unit under the floor.
According to this description, the lift pump runs all the time the engine is running. Also, if it is correct that the HP pump needs 0.8 bar before it kicks in, the engine might not start if the lift pump is on the blink, or the filter blocked. Immediately the engine starts, the battery voltage will rise a volt or two, which might get things going, at least for a week or so.
Fred
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chelseaalan
- Posts: 9
- Joined: 09 Aug 2008, 10:16
- Location:
- My Cars:
HP pump
Hi Fred,
what a very informative reply.The original problem with my non starter happened within a few days firstly going from turning over 5-6 times to non start without easystart.
The RAC guy seemed to know what it was straight away and I don't know if this has made me look at the HP pump as the only prob.
I don't know if it makes any difference but at the same time the glow plugl light on the dash packed up.I out even when the ignition is just turned on,it used to show for about a second before this.
You said the LP pump could possibily be at fault or the filter.How can I check this as I can hear the pump 'buzzing' and where is the filter?.
Any info you can give me would be most grateful as I have limited mechanical knowledge and if this goes into the shop I will get hit for hundreds of pounds that I cnnot afford and it may not even be the pump.
Boy would I be GUTTED argh!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!1
Cheers
Alan
what a very informative reply.The original problem with my non starter happened within a few days firstly going from turning over 5-6 times to non start without easystart.
The RAC guy seemed to know what it was straight away and I don't know if this has made me look at the HP pump as the only prob.
I don't know if it makes any difference but at the same time the glow plugl light on the dash packed up.I out even when the ignition is just turned on,it used to show for about a second before this.
You said the LP pump could possibily be at fault or the filter.How can I check this as I can hear the pump 'buzzing' and where is the filter?.
Any info you can give me would be most grateful as I have limited mechanical knowledge and if this goes into the shop I will get hit for hundreds of pounds that I cnnot afford and it may not even be the pump.
Boy would I be GUTTED argh!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!1
Cheers
Alan
Hi Alan,
The motor trade normally tries diagnostic tools in combination with experience, and unfortunately in this case the RAC man could be correct. The other (scientific) approach is to chase through the system checking whether things fit the known design. In this case, the delivery to the HP Pump should be above 0.8 bar.
So before committing to a new HP Pump, it may be worth trying to check pressure at the filter output. If it reaches over 1 bar during the initial 3 second burst of the lift pump, the lift pump and filter are likely OK. If lower, suspect the lift pump. Unfortunately, if you do not have some DIY experience, this may be difficult, but here is what I would do in the circumstances.
You would need a suitable pressure gauge for this range, and some way to T into the pipe. After removing both the plastic shrouds over the engine area, the filter unit is a round black plastic housing with 5 pipes at the front of the engine. The input is lower right, underneath are the two heater pipes, and the T on top has the tank return to the left, and the output to the HP Pump on the right. All pipes have quick release fittings, you hold the coloured tab pressed and pull it off.
A word of warning! The HP Pump is extremely sensitive to any contamination, even a small quantity of fine dust, so scrupulous cleanliness is essential. It is worth having someone operate the ignition switch when you disconnect the output pipe, letting some fuel spew out to flush any dirt. Then take great care everything connected is very clean.
It is also possible to monitor the high pressure sensor on the common rail using a voltmeter. According to Revue Technique, the pressure transducer output should be 0.5 volt before starting, about 1 volt (for 200 bar) during starting, and up to 4.7 volt corresponding to 1350 bar. You would need to have a bit of electrical knowledge. Anyway, this signal is fed to the ECU, and is what the RAC guy will have read out, so unless the input pressure is low it probably does indicate a failing HP Pump.
A question. Has the filter been changed recently during a service? There have been posts on this forum where HP Pump failure has followed getting the filter element changed, and advice has been to replace the complete filter unit, not the element. The design is poor, and it is easy to let contamination cross into the filtered side when the element is pulled out.
Fred
The motor trade normally tries diagnostic tools in combination with experience, and unfortunately in this case the RAC man could be correct. The other (scientific) approach is to chase through the system checking whether things fit the known design. In this case, the delivery to the HP Pump should be above 0.8 bar.
So before committing to a new HP Pump, it may be worth trying to check pressure at the filter output. If it reaches over 1 bar during the initial 3 second burst of the lift pump, the lift pump and filter are likely OK. If lower, suspect the lift pump. Unfortunately, if you do not have some DIY experience, this may be difficult, but here is what I would do in the circumstances.
You would need a suitable pressure gauge for this range, and some way to T into the pipe. After removing both the plastic shrouds over the engine area, the filter unit is a round black plastic housing with 5 pipes at the front of the engine. The input is lower right, underneath are the two heater pipes, and the T on top has the tank return to the left, and the output to the HP Pump on the right. All pipes have quick release fittings, you hold the coloured tab pressed and pull it off.
A word of warning! The HP Pump is extremely sensitive to any contamination, even a small quantity of fine dust, so scrupulous cleanliness is essential. It is worth having someone operate the ignition switch when you disconnect the output pipe, letting some fuel spew out to flush any dirt. Then take great care everything connected is very clean.
It is also possible to monitor the high pressure sensor on the common rail using a voltmeter. According to Revue Technique, the pressure transducer output should be 0.5 volt before starting, about 1 volt (for 200 bar) during starting, and up to 4.7 volt corresponding to 1350 bar. You would need to have a bit of electrical knowledge. Anyway, this signal is fed to the ECU, and is what the RAC guy will have read out, so unless the input pressure is low it probably does indicate a failing HP Pump.
A question. Has the filter been changed recently during a service? There have been posts on this forum where HP Pump failure has followed getting the filter element changed, and advice has been to replace the complete filter unit, not the element. The design is poor, and it is easy to let contamination cross into the filtered side when the element is pulled out.
Fred
... or a faulty injector, this is very common, a sticking injector will cause fuel not to build up enough pressure & therefore it wont start.thorter wrote:. Anyway, this signal is fed to the ECU, and is what the RAC guy will have read out, so unless the input pressure is low it probably does indicate a failing HP Pump.
You need to remove the return pipes from the injectors & clamp the pipe off, disconect the cam sensor (to stop the engine starting) & crank the engine, you should get no more than a trickle out of each injector, if one of them is spilling out a lot more that the others you have found the problem.
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chelseaalan
- Posts: 9
- Joined: 09 Aug 2008, 10:16
- Location:
- My Cars:
xsara HP pump
Hi Guys,
Hopefully the long saga of my non starting easystart drinking 2.0 sx is over.
A techy from my local Peugot dealership has come out to look at the pump.
He confirmed that it was not pulling pressure (showing me on his little magic laptop) so after taking off the fuel pump regulator and giving it a clean/blowout and hey presto my little baby now starts every time as she used to leaving me £20 lighter and a great deal happier.
Next week he will be back to service my 2ltr baby.
Thanks to all you guys for all your help and very informative answers.It is very much appreciated.
Many thanks
Alan
xsar 2,0 HDI sx.
Hopefully the long saga of my non starting easystart drinking 2.0 sx is over.
A techy from my local Peugot dealership has come out to look at the pump.
He confirmed that it was not pulling pressure (showing me on his little magic laptop) so after taking off the fuel pump regulator and giving it a clean/blowout and hey presto my little baby now starts every time as she used to leaving me £20 lighter and a great deal happier.
Next week he will be back to service my 2ltr baby.
Thanks to all you guys for all your help and very informative answers.It is very much appreciated.
Many thanks
Alan
xsar 2,0 HDI sx.