P1271 / P1272 error codes

[clampy]

Poor lux is a bit sick

280ks, 2009 D4D

injectors done at 200k, manifold clean done at 120k

seemed down on power, or maybe more accurately torque. 4th gear flat road takes over 10 seconds to get from 100 to 110 on gps. when i put my foot down it seems to have pickup for a split second before feeling like its just taking its sweet merry time to get to speed, most noticeable over 80. tyres just under 32" so bigger but not huge amount. no other mods to drive train. it has an ARB dual battery tray.

this time, to revisit the slowness i sent to my mech to get the manifold cleaned, but on start up after bleeding / priming the fuel system, it threw these codes P1271 and P1272. currently starts in limp mode. mech said fuel pressure in the rail was low / below target but i am unsure on specific numbers, ill get that from him

one code is fuel rail pressure valve malfunction (1272), and the other is missing signal from injector driver to ecu regarding the fuel pressure valve(1271). (since its the injector driver that talks to the pressure release valve) because one of the codes is a missing signal or missing confirmation, its gotta be wiring, or the sensor at the end of the wiring - in this case the pressure valve itself? There seems to be known issues with battery trays that relocate the injector driver (EDU) which can lead to wiring loom problems.

in recent months i also noticed the fuel pressure, when it gets up to 19000 psi or so (monitoring via generic OBD2 app), fluctuates by about 800 psi. only the other day i saw on the Techstream analysis thread that this means the SCV could need replacing. its a long body SCV.

current theories for codes are:
1 pressure valve failure
2 EDU (injector driver) or EDU loom failure due to ARB battery tray causing rubbing on loom (since ARB tray install relocates EDU)

theories for low power:
1 worn SCV
2 turbo vane stepper motor bolt is loose, causing vanes not to move correctly (unlikely but its an easy check so throwing it in)
3 fuel in-tank pickup screen blocked
4 faulty EDU / EDU loom


anyone got any better ideas? or things to check? mechanic will be doing a test of the looms relating to the EDU.

punch this "dtc p1271 1272 type:pdf" into the main searchy engine on the web and you get a pdf of the description and troubleshooting for these, otherwise i lifted other ideas largely from reading posts around this forum

[Gipsy]

Has your Hilux got a chip? Some chips make the common rail pressure valve blow off.

[clampy]

No mate no chip. no other drive train , engine, ecu, tuning mods.

[hiluxxury]

Its a rare one. Some have pointed to the pressure sensor on the common rail but its hard to confirm. Baileys diesel when the were active here posted a link that goes nowhere now. Perhaps give them a call?

[clampy]

So there is a plug that is on the same loom. Plugs in somewhere hard to reach down under the throttle body. Swirl valve? Dunno, it wasn’t me. But that wasn’t plugged in all the way and pulled out. That will cause the above codes. Sorted now

Anyone know SCVs? My rail pressure fluctuations are 800-900psi and techstream thread says replace. So might order one from baileys. It’s a long body SCV.

Currently setting up a windows XP VM to run techstream on my arm cpu laptop. Just need to make sure the USB device picks up the right driver and should be good to go. Will report back

[hiluxxury]

Could be a fuel supply issue as well. Have you done anything to the fuel filter recently?

A contaminated SCV can also cause some of the headaches you describe.

[clampy]

No recent changes that correlate to a drop in performance.

I had swapped fuel tank last year but I didn’t check the pickup screen coz I’m an idiot. Didn’t notice a change.

Last time the fuel filter light came on I replaced that and it was marginally better performance but still struggled to rev when under load ie trying to get from 90 to 110 requires planning.

If I rev it out in 3rd it takes ages to get from 4 to 4200 and good thing that’s redline coz unless I’m going downhill it won’t rev past 4200 in 3rd. Not that I drive it like that normally haha, but that can’t be right?

[Brokenlux672]

Hey mate got the same issues have you fixed it yet I replaced the injector driver module still no dice this is spinning my head around