Member Since: 08 Jun 2022
Location: South
Posts: 16
Low Fuel Pressure - Low Pressure Pump??
Hi all,
I seem to fix one problem and another appears; the joys of D3 ownership!
I relatively recently (June/7k miles) serviced the car including a new fuel filter (I believe Mahle from memory). It has driven perfectly all this time, however driving home last week and I had an ‘Engine System Fault’ message, followed by ‘Special Programs Unavailable’ (or something like that). The car lost power and throttle response, dropped the gears and it seemed to come back to life. I drove it to work yesterday and it seemed to occur frequently when I put the engine under any sort of load, uphills being the worst. I didn’t get the special system error, but the Engine System fault was frequent to say the least. I had to pull onto the hard shoulder because the car had slowed to 10mph up a hill on a national limit main link road, waited in neutral and it pulled off as though nothing had happened. Got to work safely an spent time googling. The IID tool read error P2290-00 (6C) which points to Injector Control Pressure too low if this is any help although I know lots of codes work in tandem.
Managed to make it home, I only got the error once or twice driving at a very steady 40mph, stayed in 4th gear and it seemed to be happy enough - I didn’t try and push it just to be safe. I had the IID tool plugged in on the way home and when the issue did occur, it looked like the fuel pressure dipped, spiked then consistently dropped moments before the engine fault. Spent the evening on this forum and google trying to find ways to diagnose, stumbling across the walkthrough provided by Robbie on the low pressure fuel pump.
I have been out there today and tried to follow Robbie’s write up, although I’m not sure how accurately so I’m hoping some of you may be able to point me in the right direction and understand the results.
1. Unplugged the relay for the fuel pump and read the DC amps in place of the relay with the IGN off, which came out at 3.59a. I didn’t measure at the fuse with the relay in and the IGN on, I forgot. Is this worth doing?
2. I read the pressure at the Schrader valve in the engine bay with the IGN off, which was 0 bar.
3. Switched the IGN on, the pressure read at 0.45 bar.
4. Turned the engine on and the pressure dropped to 0.3 bar, with the needle vibrating?
5. Took the engine to 2000rpm and the pressure dropped to 0.2 bar.
Firstly, are there any tests or combinations that would tell me the issue beyond the above, or does the above point to a fault in the LPFP? The readings seem low to me (especially the current draw) but the pressure didn’t seem shockingly low - I can’t work out if the pressure should drop under load or not and what this points to the fact that it does.
I gather there is a connector behind a wheel arch that could be loose, is it worth checking this or as the issue is relatively predictable I assume this is unlikely. Finally, could this just be the result of crap fuel?
My gut based on the above is that my LPFP is on its last legs, not quite gone yet but possible? I’m hoping its not the HPFP as that would have to go to a garage and this close to Christmas who knows when I will get it back…
Any help appreciated, if there’s extra steps to try to diagnose I can hopefully do those. I’m just really hoping it’s something I can do at home! Many thanks in advance!!
19th Dec 2023 4:58 pm
ds23man
Member Since: 19 Jan 2013
Location: Ainum
Posts: 227
How many miles did the car?Citroen DS23IE
Audi A6 2.4 V6 Avant Quatro (1998)
Audi 80 2.6 v6 Cabriolet (1996)
John Deere 4240S
McCormick 323
19th Dec 2023 6:28 pm
StillBasilisk
Member Since: 08 Jun 2022
Location: South
Posts: 16
It’s currently on around 177k miles. I serviced it at 170k ish, having taken ownership at 160k.
19th Dec 2023 7:01 pm
ds23man
Member Since: 19 Jan 2013
Location: Ainum
Posts: 227
HPFP.....
It is a wear and tear part, like your brakes, tires and EGR valves. Had the same problems at this mileage, dropped the tank to replace the LPFP and ended up replacing the HPFP.Citroen DS23IE
Audi A6 2.4 V6 Avant Quatro (1998)
Audi 80 2.6 v6 Cabriolet (1996)
John Deere 4240S
McCormick 323
19th Dec 2023 7:08 pm
PROFSR G
Member Since: 06 Mar 2017
Location: Lost
Posts: 5043
Re: Low Fuel Pressure - Low Pressure Pump??
StillBasilisk wrote:
Any help appreciated, if there’s extra steps to try to diagnose I can hopefully do those. I’m just really hoping it’s something I can do at home! Many thanks in advance!!
Pull the fuse for the LPFP and see how it drives, just don't gun it! If it drives OK without the aid of the LPFP then the HPFP is likely OK and the problem is in the tank. ie Duff LPFP, or if there's brass particles in the tank the HPFP is on it's way too.yµ (idµ - eAµ) ψ=mψ
19th Dec 2023 8:00 pm
StillBasilisk
Member Since: 08 Jun 2022
Location: South
Posts: 16
Thanks for the replies, appreciated. I’m not sure I want to jump to conclusions on the HPFP just yet, largely because I’m not sure I can face taking the engine bay apart!
If that were the case though and it is indeed the HPFP, based on it being an 05 D3 2.7 I have seen a couple of part numbers that could match; is this the case or is it the same pump (ie eu3)?
When you say unplug fuse 1 and drive, if the current issue is only there when I stress the engine (ie uphill) do I have to replicate the scenario to know if that pump is the issue?Or are you saying that if it doesn’t drive properly at all with the fuse pulled then the issue is HP? Fingers crossed the issue is LP related, much more confident with that!
And this is my daily driver for work so anything to be done I’d hope to do over Christmas! Thanks again.
20th Dec 2023 7:07 pm
PROFSR G
Member Since: 06 Mar 2017
Location: Lost
Posts: 5043
Removing the fuse on the LPFP and driving the car will help you to lean to either the HPFP or the LPFP depending on how the car performs during the test.
It's not fool proof, but does give a good indication as to the HPFP's solo performance capability. And, that of it's internal pumps/sensors before firing that very expensive parts cannon!! I would personally lean towards the LPFP first! Not least because the is the much less expensive component to replace, but also because you can clean the pickup gauze and examine the tank contents for any signs of HPFP failure (brass shards)
If you find brass in there the HPFP is kaput, if not just fit an OEM LPFP, (Genuine LR orBritpart) genuine fuel filter, and go from there. yµ (idµ - eAµ) ψ=mψ
20th Dec 2023 7:40 pm
StillBasilisk
Member Since: 08 Jun 2022
Location: South
Posts: 16
Okay, I will try that thank you. I have ordered a LPFP in the meantime just because I can then fit it over the break if required rather than diagnosing it and waiting for weeks for one to arrive! If it is the HPFP then I might have more of a problem, but as you say start cheap and work up!
21st Dec 2023 7:29 pm
StillBasilisk
Member Since: 08 Jun 2022
Location: South
Posts: 16
So update to my woes…
Replaced the LPFP which was a job in itself. Couldn’t see brass in the tank but I didn’t fully empty the tank as I didn’t have anywhere else to put the fuel (I guess I filled up just before the issues!)
I bit the bullet and ordered a HPFP from PF Jones, I gather it’s a recon one from Siemens. Spent the past few days replacing it, I have to say it is one of the worst designed engine bays - to the point one of the bolts holding the pump down is covered by the crankcase breather pipes. The pulley on the back of the pump is fitted in a hole in the rear belt cover, but you can’t pull the pump forward to release because the filter housing is in the way. Anyway. High pressure pump replaced, I have just got it all back together, primed the system and it started! Left it on idle for 5 mins or so whilst I cleared away tools, then drove it out of the garage, turned it around on the drive, went to pull away and it cut out. Now it won’t start at all. Cranks fine, but never catches. I read codes and it looked as same codes appeared as before, cleared them, cranked a couple of times and re read faults, nothing to note.
I am 90% sure connectors etc were clear and well sited as putting it all back together, so I don’t know what the issue is. I can’t believe the duration it was running for was just using up fuel within the injector pipe… maybe I’m wrong? Going back out tomorrow to start taking apart again, but I am leaning towards the recon pump being duff. We shall see!
Thanks for your help to this point regardless!
6th Jan 2024 9:58 pm
PROFSR G
Member Since: 06 Mar 2017
Location: Lost
Posts: 5043
Did you bleed it properly? They take quite a bit of bleeding and often require a lot of cranking to fill the injector lines fully.
You won't get codes until it runs or after a few start cycles,.yµ (idµ - eAµ) ψ=mψ
6th Jan 2024 10:52 pm
StillBasilisk
Member Since: 08 Jun 2022
Location: South
Posts: 16
Been out there today, redid parts I looked at yesterday, put it back together again. Belt is on and appears to turn. IGN on for 20s, off, repeat 30 times. No air coming out the schrader, straight fuel. Fuel was in the return pipes from the injectors which implies they are receiving fuel? Cranked 4 or 5 times for 5 secs or so, nothing. Got the battery on charge but I’m now out of ideas. Meant to be driving to work tomorrow!
7th Jan 2024 3:00 pm
PROFSR G
Member Since: 06 Mar 2017
Location: Lost
Posts: 5043
Still no codes?yµ (idµ - eAµ) ψ=mψ
7th Jan 2024 3:17 pm
StillBasilisk
Member Since: 08 Jun 2022
Location: South
Posts: 16
Not engine related! All audio and auxiliary.
7th Jan 2024 3:19 pm
PROFSR G
Member Since: 06 Mar 2017
Location: Lost
Posts: 5043
Try cranking for a bit longer, if there's fuel entering the cylinders it has to start. Unless there is no fuel entering because the injectors are not firing! Check wiring to the injectors, HPFP, FRPS, (EMS and ECU fuses?)yµ (idµ - eAµ) ψ=mψ
7th Jan 2024 3:38 pm
ds23man
Member Since: 19 Jan 2013
Location: Ainum
Posts: 227
Sounds like a lot of air in your HP pipes to the injectors...Citroen DS23IE
Audi A6 2.4 V6 Avant Quatro (1998)
Audi 80 2.6 v6 Cabriolet (1996)
John Deere 4240S
McCormick 323
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