Please give me strength

[duke900]

After a long long time trying to get my s4 running right it still hasn't worked. No matter what I try I can't get s4 to run on both cylinders. I have no power getting to the rear jet on the throttle body, changed sensors, jet, checked wiring loom, checked and swapped ecu but still no joy.

Has anyone got another wiring loom and another ecu so I have changed everything to get it to run

Nick

[Martin C]

The injector is of course only activated intermittently by the ECU as the engine rotates. If you've checked the wiring loom and have good continuity from the ECU connection to the actual rear injector, whilst the front injector works OK, this suggests a faulty ECU. However, it may be worth disconnecting the ECU harness & rear injector, and testing this totally isolated wiring circuit with a temporary power supply and a small bulb. A test multimeter uses a very low current to test for continuity (to avoid damaging components), and can show apparently good continuity which fails under the higher actual working current. If the wiring won't pass enough current to light a small bulb, the wiring is faulty.

[duke900]

I have tried that too, I have tried the earth and positive on both power supplies to the injectors. The front has a definite positive and earth, however the rear has no positive earth and power. I used a bulb and on the rear power supply to injector and it just lights up very dimly though.

Any more ideas !

[satan916]

I've got a stock S4 ECU I can let you borrow (I'll need to find it as it's burrowed it's way into the deepest recess of the garage), let me know if you want it to try.

[duke900]

Thanks I think I need to get my hands on a complete wiring loom to solve the problem, can any body help with that?