Advice on possible faulty D5 Fuel Pump

[lpg224kw]

Hi

Advice sought re the following
car V70 D5 2002
symptoms

1. Occasional engine cut out, typically when pulling away from standstill or when moving slowly, engine having been at low load. "Urgent Engine Service" warning produced. Turning the ignition off and then back on again has always got the car going again.
2. Erratic low load throttle response. Most clearly demonstrated when steadily opening the throttle with the car in neutral, throttle response is non linear, i.e. the revs jump up in big steps and then remain stationary or even fall back. Happens most around 1500 rpm, with the revs jumping in a 500 rpm step upto 2000 rpm. On closing the throttle, the behaviour is reversed with the revs hanging then jumping down. A plot of throttle position and revs against time would not look pretty.
3. When trundelling along at 40 mph in top gear the engine occaionally apppears to pulse at a frequency of ~0.5 - 1 Hz as if the throttle was being repeatedly opened a bit then closed a bit, although of course the right foot is staying put. (because I'm trundelling along...) Mway driving appears fine at the moment


The cut out behaviour has suddenly got more frequent. Visit to main dealer for diagnostic test returned error codes ecm 2505 fuel pressure too low and ecm 2503 fuel pressure fault. Dealer checked pres sensor, filter injectors and pipework but could find no faults. they diagnose faulty fuel pump thats £1780 fitted to you sir.

my sentiments on the matter would not last long on a well moderated forum.

any advice/recommendations would be greatfully received, particularly on the probability of correct diagnosis and where to get the fuel pump (low /high pressure + fuel pressure regulator, is this a Volvo only part?)

also Main dealer has said that the ECU needs are program if an elctromechanical part such as the FP is fitted... Really??

[S60-MBS]

Try the simple and cheap cure first by changing fuel filter.

[lpg224kw]

Replaced fuel filter ~1000 miles ago. No improvement

[Bernard333]

I am assuming due to the high price that your garage diagnosed the two stage high pressure mechanical fuel injection pump and not the in tank electric pump ? I had problems with fuelling that were vaguely similar to yours now cleared up but never correctly diagnosed and still dont really know what caused it in the first place despite various garages looking at it . First off my electric in tank fuel pump did fail , I know that because I still have the old pump and its dead ,it was replaced using a pump from an old Toyota diesel at a cost of £10 for the pump itself but in taking the pump/sender unit out of the tank the person doing the removal was so ham fisted they broke the union to the syphon pipe which straddles the two halves of fuel tank but they didnt realise how critical this small part was , I found out when my car broke down in France still showing over half a tank of fuel but thats a separate matter . You can have the low pressure pump pressure tested and it should give out 2bar when its on , its controlled by a relay and for normal driving you dont need it except for starting and when you accelerate because the mechanical fuel pump mainly sucks fuel through for normal driving . My electric fuel pump failed at about 115k miles . I have been told by two different experts one on this forum and another at a diesel specialist in Blackburn that the high pressure pump on the D5 is very reliable and unlikely to fail . If the pump is failing due to 'eating' itself up and you have the plastic cup type fuel filter with paper insert rather than metal canister then you could have a look in the bottom to see how if metal particles are in there , if the fuel pump is eating itself then it can send the metal particles back down the return fuel line to be deposited in the bottom of the cup , mine was doing that but still not enough to diagnose a failed fuel pump and that was nearly 20k miles ago. I believe replacing the fuel pump is straight forward bolt off / bolt on with no adjustments , you are supposed to fit new high pressure pipe and as far as I know no software resetting is required , there have been a few of these sold on ebay for £80 and I had quotes from breakers for around £300 which seemed a bit steep . There was also problems with the fuel injectors on some early D5 engines which I think were only resolved on late 2003 models it is possible you could have a failing injector . The in tank electric fuel pump can fail gradually over time although I am told these are also normally very reliable but if its failing the effect will be to starve the high pressure pump , you could also have a partial blockage somewhere , an easy test is just remove the rubber pipe feeding the mechanical pump and switch on the ignition making sure you have a container to catch the fuel that should pump out .

[john1958]

Might be worth checking if air is getting into the fuel line.
I had similar symptoms but not so serious and the fault lay in corrosion of the fuel pump as it sits at the back of the car and exposed to raod salt etc. The corrosion was at the mating surface causing the seal to open slightly and air would get in. My car is 2002 and was 6 years old then.

[lpg224kw]

Thanks guys

I have made some progress having located a friendly dealer in 2nd hand volvo parts who suggested that I didn't buy one of his many injector pumps because (in agreement with Bernard) they very rarely fail. Also he sells them for £80 ( cf £1200 for a new one !!!) the fitting is straight forward and there is no need for ECU interfacing providing you correctly match the pump with the injectors. So this is a big relief and it looks like I should be able to find a cost effective solution... eventually

How do you test for air leaks.... can you tell by examining the filter contents? or how else?

The problem is intermittant and worse with heat in engine bay (pull into service station after 200 miles of Abahn sillyness, leave engine ticking over to keep turbo lubricated, after ~ 5 mins we set off and almost as soon as we get going the engine cut outs when the engine bay temp at a max) I think I have a failing sensor with the fuel pressure sensor or the fuel pressure control valve being favourite. It may also be a MAF sensor, Accelerator pedal position sensor or the ECM..... How sophisticated are the diagnostics, can they identify faulty sensors? What about the injectors, can they be diagnosed as faulty or is this only diagnosed by trial?

I'm starting to get into this. 48 hrs ago I was very despondant thanks to ignorance and a feeling of utter helplessness when faced with a hugh potential bill. Now I can see that most of the potential causes of this problem can be fixed by me with 2nd hand parts (probably) for a fraction of the cost I was originally faced with. My V70 D5 is finally old enough for me to consider DIY as the only cost effective way forward, and guess what I'm relishing the prospect

Ralph

[Bernard333]

Ralph , I am just thinking that as yours is 2002 model you probably have the metal canister type fuel filter so you cant easily have a look at the sediment the same as the post 2003 D5s with the plastic cup and paper insert . The number of codes that are produced with OBD11 and the Can system mean that for example for the 02 sensors you get one code for voltage too low or another for no signal etc so I would say the codes read out would be good enough to highlight a potentially faulty sensor but can also be misleading . Being an electronics & control engineer from the jurassic period I am happy enough testing sensors individually as the way they work hasnt changed much since then and most of what you find on a car seems to me to work the same way as sensors you would find on a production line or in an industrial process control system (its the actual control system / ECU and data transmission which is still a mystery to me) , you get a voltage or no voltage or some voltage in between which can mainly be easily measured using a cheap multimeter , some sensors also need a voltage input . O2 sensors can be tested using the heat from a gas flame on your cooker and should give a range of 0.1 to 1V or more but you also risk damaging the sensor so this is a last ditch approach . Front 02 sensor switches five or more times a second and the rear less than once every few seconds when its working in the cat , you cant see this with a cheap multimeter but you can using an old oscilloscope bought off ebay , some of these cost thousands of pounds years ago and now you can pick the same one up for £20 , most of these are not really suitable for auto electronics but with patience they work and so far I dont think I have damaged anything and I dont want to invest in a dedicated item such as a Picoscope which costs over £500 however if I had the money one of these seems to me to be a viable alternative to the official Volvo diagnostics which would cost thousands of pounds and has the benefit of working on any make of car . You can download OBD11 basics free of charge at scantool.net and this will apparently do basic engine diagnostics giving live data but as far as I am concerned this would cover 90% of what I need , I have done it but have not been able to get it to work on my D5 but at least I dont seem to have caused any damage by plugging it in , you do however run the risk of completely wrecking the ecu according to some experts so you use it at your own risk , you need an older lap top with serial port the modern ones dont have one (you can use a serial / USB emulator but I believe these are not reliable ) . The internet has loads of free information on the testing of various sensors. A more basic approach for example with the MAF is just disconnect it and take the car for a drive and then reconnect it , did that with mine in January and it cured a long standing problem that has not come back although I find it hard to believe that its really cured as I am relying on the problem having been a dirty connection and I cant even see which one it was . As you may have gathered I have got past the stage were I have any worries about connecting into the electrical system as I was seriously going to just sell the car in January as a non runner but its running great now and generally speaking I have so far found the electrical system although problematic quite resilient to tinkering about with .

[lpg224kw]

SORTED!!!

2nd hand injection pump for £80, fitted myself in ~ 1 hr 45 mins start to finish and the car is transformed

On the negative side, how can a dealer quote £580 labour for a job that took me less than 2 hours reading from a Haynes manual????

Is there a RANT forum to air views on such things?

[v70-xc90man]

Originally Posted by lpg224kw

SORTED!!!

2nd hand injection pump for £80, fitted myself in ~ 1 hr 45 mins start to finish and the car is transformed

On the negative side, how can a dealer quote £580 labour for a job that took me less than 2 hours reading from a Haynes manual????

Is there a RANT forum to air views on such things?

hi which pump was it the electric tank pump or the mechanical engine pump?
please??

[Bernard333]

My guess for what its worth is that lpg fitted a replacement engine mounted injection pump and not the in tank pump but on the other hand its that pump which I am led to believe rarely fails and also I wouldnt understand how the engine mounted pump could fail intermittantly but I can see that the in tank electric pump certainly can fail intermittantly before finally stopping working altogether . Also please ignore me rabitting on about 02 sensors in a previous post because there are of course no O2 sensors on the 163bhp D5 engine , I have three V70s and its one of the petrol engined ones that I was connecting my oscilloscope to back in January when I had the two cars off the road and was trying the subsitution method of repair without great success , I have since learned that the output from the front unit isnt as simple as high/low it does give a readable signal to a scope but its very misleading , maybe better sticking with the output from a dedicated fault code reader like the ppc/bsr/nordic .