Toyota Rav4 D-4D Diesel - Fault Code Identification Problem

[szwajcarek]

Hello
I have a problem with Toyota Rav4 with D4D CR Diesel. I have red the faut codes using Bosch KTS and the Fault number is:
P1226 - Unknown Fault
Is someone able to tell me the description of the fault. I have searched in Autodata, Vivid Workshop ETC, but did not found it.
The problem is, that during the drive, suddenly the Fuel Pressure fall down and the engine runs in failure mode. In my opinion the problem may be in injectors or in Fuel Pressure Regulating Electro-valve.
Thanks in advance.

BR

[pkatra]

Hi
P1226 has various definitions, all of which are related to Throttle position sensor, Control Sleeve Malfunction or Fuel Pressure leakage.

The Toyota Code 1226 = Excessive fuel pressure leakage.

You might find that this code is being caused by something else in the fuel delivery system that is putting the Fuel Pressure Leakage out of its Parameters i.e. Injector lift Sensor(if fitted),Throttle position sensor or Control sleeve on the pump.

You say that you have replaced the Pump; this may need calibrating to both the Electronic control unit and the lift sensor (if fitted).

Due to the complexity of this system I would recommend that you find a Garage with suitable Diagnostic Equipment to test the operation of all these components and calibrate if necessary.

I hope this is of help to you

[Meat-Head]

the word on street is on peugot's and shitty renos crysler there is a 'high pressure' solenoid in the top of the diesel pump, these go fauly and cause MASSIUVE pressure in the rail, and causes limp mode, approx ?70 from a basch dealer, but DONT touch te end as it is VERY VERY VERY VERY fine mesh, it kills them more if you touch it

[JinDevil]

I have had the same problem

[szwajcarek]

Hi
Thanks for fast replies !
Toyota is really hard to diagnose with Bosch KTS, and as it is the only multi diag tool that I have, I will send it to someone with Techstream, etc.
I have not changed the fuel pump, but as Meat-Head suggests - it may be the " 'high pressure' solenoid ", but there is something like that:
After start, I have disconnected the high pressure selenoid, and the engine runs in failure mode. Let say that it runs quiet smooth, you can run till 3000rpm, but after few minutes the same happens, the fuel pressure suddenly drops down. This why I gues it may be problem with injector leaking (I don't know how to call it, let say that they don't keep up the pressure in rail - I have had similiar problems in Renault Dci engines) ?

BR

[dafdiagnos]

does it start white smoking & knocking when pressure drops off? when you disconnect pump e.m. valve the pump will run at full pressure

[szwajcarek]

Hi
Yes dafdiagnos exactly this happens:
when start smoke appears and knocking when pressure drops off.

BR

[dafdiagnos]

if you've got access to a good air compressor you want to trace & disconnect spill rail- either thru head or individual return- not sure on this engine & remove glow plug, fit a test coupling to injector & at @ 120psi check for stuck nozzles- will feel air returning or a bit of spit works well- check for bubbling

[Meat-Head]

if you've got access to a good air compressor you want to trace & disconnect spill rail- either thru head or individual return- not sure on this engine & remove glow plug, fit a test coupling to injector & at @ 120psi check for stuck nozzles- will feel air returning or a bit of spit works well- check for bubbling

confused, any chance of a rude photo?

[szwajcarek]

The car left my garage and was brought to Toyota, he will let me know what was it.
Anyway dafdiagnos could explain more the test procedure with compressor ? It maybe helpfull for future.

Regards

[dafdiagnos]

The car left my garage and was brought to Toyota, he will let me know what was it.
Anyway dafdiagnos could explain more the test procedure with compressor ? It maybe helpfull for future.

Regards

if you remove injector pipe from injector & fit test pipe with pcl coupling on end, disconnect spill return if thru cylinder head, or spill pipe from injector if not. if return thru head then connect air compressor- if air coming out then nozzle stuck open or weak. if return thr normal spill rail, remove glowplug & feel for air from hole. also can remove injectors, connect test pipe, dip injector nozzle in container of diesel & see if it blows bubbles

[Meat-Head]

if you remove injector pipe from injector & fit test pipe with pcl coupling on end, disconnect spill return if thru cylinder head, or spill pipe from injector if not. if return thru head then connect air compressor- if air coming out then nozzle stuck open or weak. if return thr normal spill rail, remove glowplug & feel for air from hole. also can remove injectors, connect test pipe, dip injector nozzle in container of diesel & see if it blows bubbles

so your saying is the airline is 120 PSI and it needs 100000000000000psi
to work the injector, so if you get ANYTHING out of the glowworm hole, or leak off, disconnect the PCL airline fitting and, remove the injector then reconnect the airline fitting, release the PCL connector and see how close to the bin you can get the injector????????

Thanks Meaty.

[szwajcarek]

Hi, Again
Well the only pressure that I am able to settle is about 35bar (490Psi)- I have an nitrogen cyinder that I use to check air conditioning system leakage.
I have found a book, about diagnosis of CR Diesel systems. This is what author wrote about injector leakage:
1. Nozzle leakage: To diagnose this kind of problem, we need to dismount the injector and put a pressure about 40MPa (400bar ) ? (off course using some special tools). During this test no fuel should leak through the nozzle, and from the overflow only little fuel should be noticed ? the fuel level should increase in speed of 2mm per 1 second in a transparent pipe. (You can see this special construction on photo nr 1 with this measuring tape under the transparent pipe ) ? This is impossible for me because I don?t have such equipment.
2. checking Overflow rate ? this is the only thing we are able to do, because we don?t need to dismount the injector. You need to disconnect overflow pipes and connect some transparent pipes with graduated glass with a scale. The test maybe done while crancking or idling. The fuel in the graduated glass should fill up slowly, and after some time we should compare each glass :
a) Bosch says that: an injector is leaking if the overflow fuel level is 3 times higher then in other glasses
b) Delphi piezoelectric injectors are imposible to test because they have no overflow.
I have found some test equipment from Lehnert ? see PDF attachment.

Regards

[Preecha508]

Hello
I have a problem with Toyota Rav4 with D4D CR Diesel. I have red the faut codes using Bosch KTS and the Fault number is:
P1226 - Unknown Fault
Is someone able to tell me the description of the fault. I have searched in Autodata, Vivid Workshop ETC, but did not found it.
The problem is, that during the drive, suddenly the Fuel Pressure fall down and the engine runs in failure mode. In my opinion the problem may be in injectors or in Fuel Pressure Regulating Electro-valve.
Thanks in advance.

BR

From this code maybe 78(7) for denso tester. This mean high fuel pressure large lake from injector

[szwajcarek]

Hi
I have the newest info about it. Guys from TOyota told the owner that this is a common fault. There is a problem with overflow valve inside the high pressure pump, it leaks - costs 400Euros .

Regards