Member Since: 14 Apr 2021
Location: Trondheim
Posts: 29
Low fuel pressure codes caused by limp mode on acceleration?
Hello,
Has anyone had low fuel pressure codes caused by a fault somewhere else causing limp mode on acceleration?
The theory is something along the lines of: The fault is with another module or component during hard acceleration causing a sudden rise in RPM so the fuel pressure regulator can't keep up and the ECU registers low fuel pressure. Even though the root cause is somewhere else that is not monitored and saves a fault code.
I have chased a fault causing limp mode on acceleration for some time thinking it must be because of the codes I get relating to low fuel pressure. But then I saw a couple of comments on here where the issue may have been somewhere else. One comment was that the car had a similar issue but he kept using the car and it disappeared when the torque converter was changed??
The codes I get are P2290-00 Injector control pressure too low, P0087-00 low fuel rail pressure, or P0089-00 fuel pressure regulator performance, max amplitude. Limp mode happens every time I accelerate hard for å few seconds. Both low pressure and high pressure fuel pumps are changed to no effect. Injector balancing is within normal range. Pressure sensor on rail, fuel filter, brake pedal switch, battery also changed recently. I saw another unfortunate guy on the forum which has chased the same fault for 2 years swapping both pumps twice and fuel lines etc. so I want to be sure before I maintain the narrow focus.
The first message in the dash is HDC fault, then the other messages and suspension lowering. Does this happen everytime on limp mode or is this an indication of something?
Any help is much appreciated.
The car is a 2007 TDV6 with ECU tune and otherwise runs great and starts easily.
21st Jul 2021 7:23 pm
Torgeir
Member Since: 14 Apr 2021
Location: Trondheim
Posts: 29
Update - fault found (Edit: Fault still there)
Did a Injector leak off test and two of the injectors had excessive leak on the return. This would cause the fuel pressure to drop on the rail. Hopefully this will be the root cause for my faults. So in my case it seems the codes were indicating the correct issue at least.
Edit: Fault still there after replacing injectors.
Last edited by Torgeir on 5th Sep 2021 1:16 pm. Edited 1 time in total
23rd Jul 2021 10:15 pm
PROFSR G
Member Since: 06 Mar 2017
Location: Lost
Posts: 5062
Correct, if too much fuel is being lost via the leak back lines it can result in a code for reduced fuel rail/and or injector pressure. That's the great thing about the "leak off test" despite it's simplicity as it can help you nail down any pressure loss between the pump/rail and injectors. Thus hopefully avoiding unnecessary replacement of perfectly good but expensive fuel pumps!
The only caveat I would hold is that you do not also have a P0087 code in the mix too. (reduction in the low pressure fuel supply!)
Hopefully you have finally nailed it now, and if you have, well done for following a logical diagnostic path and thanks for sharing your experience and the results.
I know from your posts this has been a long trial for you, and sometimes that's just how it is despite your very best effort and your many tedious hours of frustrating work. Even so, it's all to easy to fire the "new parts cannon" when problems such as this occur, but to be honest the answer very often can be staring you in the face. (diagnostically)
It just takes a a logical approach, and very often a bit of lateral thinking and then, you're suddenly there!!!yµ (idµ - eAµ) ψ=mψ
24th Jul 2021 2:41 am
Glennyoung33
Member Since: 26 Jul 2021
Location: Swansea
Posts: 1
Discover 3 on acceleration into limp mode 2290 issue
Hi Torgeir did the injector turn out to be problem, I have the same problem.
I done the filter, break switch, break bulbs, I have good low pressure fuel supply.
Was going to do leak test as you did, just checking did this cure your problem. Thanks Glenn
26th Jul 2021 8:56 pm
Torgeir
Member Since: 14 Apr 2021
Location: Trondheim
Posts: 29
Update
Still no fix but we (garage and I) are quite certain it is still one of the injectors.
So the garage has been at this for a while now, had all injectors out and tested them, new tips on all 6 and 2 were fixed some more since it had a higher return leak. All done by local injector specialist company.
Since then there has been the typical knocking sound when it is warm caused by one of the injectors but only at 1400-1800 RPM and very low amount of throttle. If the throttle is increased it disappears. We spoke to the injector company and they only test the injectors at "idle" and at full throttle and a few places in-between so it could be that they miss it if it is a periodic fault in the actuating element, especially if it only happens when warm.
It is fine on idle and a leak-off test shows all injectors are good. Injector balancing show Injector 1 and 6 has values around 1000 and the rest lower. When I logged the values Injector 1 went above 1200 for a short while when I was driving slowly trying to listen for the knock. So my main suspect is injector 1, but is there a way to diagnose which one it is for sure while they are in the car?
2nd Aug 2021 8:12 pm
PROFSR G
Member Since: 06 Mar 2017
Location: Lost
Posts: 5062
I think I'd bit the bullet and buy new replacements for the suspect injectors, rather than risk an over fuelling event resulting in a broken crankshaft! yµ (idµ - eAµ) ψ=mψ
2nd Aug 2021 8:33 pm
Torgeir
Member Since: 14 Apr 2021
Location: Trondheim
Posts: 29
The plan is to buy new injectors to replace the bad one or two. The problem is to identify which one it is for sure since the fault only happens at an rpm where you can't diagnose it.... At idle they are all fine. Can I trust a injector balancing figure when it is not at idle? I have 6 refurbished injectors now so I don't want to start changing one injector around 6 times to find the fault if I can avoid it.
2nd Aug 2021 8:43 pm
PROFSR G
Member Since: 06 Mar 2017
Location: Lost
Posts: 5062
No it has to be read at idle, otherwise very specialised equipment is needed above that.
There's a reasonable possibility you might need more injectors in the near future. If you go for all 6 now it eliminates all doubt as well as risk!
Remember too Siemens/VDO say these injectors are not serviceable.yµ (idµ - eAµ) ψ=mψ
2nd Aug 2021 9:21 pm
Torgeir
Member Since: 14 Apr 2021
Location: Trondheim
Posts: 29
Update: Fault was not the injectors!
Replaced all injectors with new ones. No improvement against limp mode on acceleration. I am now back at square one. LPFP, HPFP, 6 injectors replaced, new filter again yesterday. No improvement. The only difference is that I am getting some new and different codes in addition to the olde codes.
P0089-22 Fuel pressure regulator performance - general signal failure -signal amplitude maximum
P00E -22 Fuel volume regulator control exceeding learning limit - general signal failure - maximum amplitude
P117D-00 Fuel volume regulator control exceeded maximum control limit
P2290- Injector control pressure too low
C1A02-94 Rotary encoder stuck in intermediate position - component failure - unexpected behavior
Most of these are new except for the P2290. Will try to sort out the rotary encoder first.
5th Sep 2021 1:15 pm
PROFSR G
Member Since: 06 Mar 2017
Location: Lost
Posts: 5062
Terrain response control knob might be goosed but I can't see it causing the fuel system faults.
Are the wiring/connectors to the fuel rail switch and the hpfp valves OK?yµ (idµ - eAµ) ψ=mψ
5th Sep 2021 1:23 pm
PROFSR G
Member Since: 06 Mar 2017
Location: Lost
Posts: 5062
Actually, come to think of it have you considered there might be an issue with the FRPS? Apart from the fact that it's the only bit you haven't changed, it's responsible for the injection duration and the PCV delivery.
As with the other components in the system it is not supposed to be opened/removed, and Siemens/VDO say it must be replaced complete. yµ (idµ - eAµ) ψ=mψ
5th Sep 2021 10:09 pm
Lrstaylor
Member Since: 03 Oct 2018
Location: Kent
Posts: 619
We chased p0087 codes for ages still getting g the codes randomly even after changing the hpfp at an early stage.
After checking and changing lots of parts we replaced the hpfp again......fixed.
read somehwere that some refurbished units are of poor quality and did not solve the issue, Lucas euro car parts ones if i remember correctly
I recently changed my HPFP (sent my own unit to PF jones for overhaul) and refitted and all ok now, i was getting low fuel pressure at rail code aswell
Are the fuel pressure regulator and control valve not part of the HPFP? might be why your getting these codes if the HPFP hasnt been repaired properly
granted all this is based on if its a refurbished pump
6th Sep 2021 4:39 pm
Torgeir
Member Since: 14 Apr 2021
Location: Trondheim
Posts: 29
What is the FRPS? Pressure sensor on the rail?
If so, the previous owner replaced it. I have bought another one but not fitted it yet.
The HPFP was a refurbished one.
6th Sep 2021 8:13 pm
PROFSR G
Member Since: 06 Mar 2017
Location: Lost
Posts: 5062
Yes, it's the fuel rail pressure sensor but it's critical you have the correct one which is rated for the tdv6 system. I think for that reason Siemens/VDO only make it available with the complete rail.
Though there does seem to be sensors available separately, there's no guarantee they are the same. You can confirm or otherwise by the labelling numbers on the switch. yµ (idµ - eAµ) ψ=mψ
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