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7 Posts
Discussion Starter · #1 ·
Hello, I have a 4.6 with the GEMS engine, and I have a problem that knows one can identify.

The engine on low revolutions runs poor and I looks that fails in some point’s ….
Connecting the T4 Diagnostic system, we get the following error code;
“Problem on Injector 1, open or electric failure, check connections and plugs”
“Problem on Injector 4, open or electric failure, check connections and plugs”

- The Injector’s are bout new, we already replace the injectors 1 with the 2 and the 4 with the 3, clear the codes, and then again when start the engine we get the same codes on injectors 1 and 2. So the problem is not the injector.
- We test and check the plugs and also the wires from the injectors to the GEMS ECU, with a continuity test, it’s all OK.
- We change the spark plugs and cables for new ones, and get the same errors.
- We test and change the position of the coils (its 4) and the errors are the same ….
- We have now also test a new GEMS ECU and we get always errors on Injector 1 and 4.
- The Crankshaft and Camshaft sensor’s are new.

The diagnostic T4 system always pointing for an electric problem on the Injectors 1 and 4, we think that we check everything related and don’t find anything.

Any one has an idea?????? What can we check now?????

It’s possible to have a mechanical problem? Or a valve problem or timing chain?????

Its possible to have some probems on valves or tapets, or crankshalf or camshalf ????

Any ideas????

Everything is welcome!!!!!!!!!

Thanks in advance and best regard’s
Paulo Miguel
Lisboa - Portugal
RR 4.6 HSE

7 Posts
Discussion Starter · #4 ·
Thanks, for the replays,

I as there again to make some more test´s on the RR.

The cam and Crank sensor´s are new, I tried to disconnect them and the engine stop´s, it means that is normal and they are ok.

Also I tried to disconnect the Knock sensors, it´s not improve, in fact the engine shake more, it also means that they are working ….

I change again the GEMS ECU to the new one, clear all the faults , and when run again the engine, it get again the same error´s.

Now after calling Land Rover Portugal and UK, several times ….. We decide to open the engine, and take out the heads.
It’s possible that the problem is from the Camshalf, exhaust or admission valves, valve springs or extenders to the valves not calibrated.
Or also the timing wells or chain.

Since that we will open the engine, I will order from RPI two complete kit’s for head rebuild, camshalf, timing chain.

This is the kit that I ask for ;

New Valves# (16), New Springs# (16), New Oil impregnated Valve guides# (16), (as used Range Rover 4.6 HSE). Fully enclosed Valve seals# (neoprene),

Piper Torque-Max camshaft, timing chain set, standard hydraulic tappets and all standard gaskets

Mean wile any other ideas are welcome.

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