Tdi Runs

The Tdi installation is now complete. I spent the last few days sorting out the exhaust pipe, which had some alignment problems between the first and second sections (much like the 12J’s during the vehicle rebuild), and a different routing at the back end, requiring a fabricated bracket behind the rear spring shackle mount. The front section of the exhaust has been wrapped in competition fibreglass exhaust tape to prevent any unwanted heating of the foot well or sound proofing.

The turbo charger needed the 8mm shim in the end. Though the shimming of the engine mounts helped a lot, the following fortnight saw some settling in of the rubber mounts, allowing the engine to sink a little. However, the shim works well as a solution to the foot well clearance problem – the turbo and exhaust are not at risk of contacting the corner of the foot well. The oil pipes had enough flexibility to reach the new height without difficulty.

Fitting the washer bottle became the next challenge after the expansion tank. In the end, fitting it beneath the expansion tank was the only viable location, and with the oil cooler pipes given a bit of a bend, it fits snugly and neatly. The two silicone pipes run with the main loom up to the bulkhead and then across to the left side grommets.

The wiring was a bit of a pain, running new 230A feeds from each battery in the rear too box to the engine bay (along with a control wire to regulate the split charger). The main battery cable was connected directly to the starter motor solenoid, with a 50A spur circuit around the back of the radiator to the lighting relays. The auxiliary battery was connected to the isolator switch mounted on the inner left wing. The switched output is for the winch, with a 50A spur from the live side of the switch for all the accessory circuits, including the radiator fan. The fan itself is controlled by an 88oC thermostatic switch in the bottom hose and by a manual switch on the lower dash, next to the hazard light switch. This means I can activate the fan if the automatic function fails or pre-emptively if the engine is about to start working hard.

The Kenlowe Hotstart was refitted in its original position, and some new pipework was made up to connect it, the heater matrix, the fuel heater and the engine together. Once complete, the cooling system was filled with a strong solution (60/40) of antifreeze.

The fuel system needed little alteration, having used the donor Discovery’s filter housing. Some new lines had to be made up between the filter and fuel heater, and the heater and injection pump, but this was not difficult. However, I had overlooked the fact that the new system would leave the filter unheated – the 12/19J injection pumps send their spill fuel back to the filter, but the Tdi sends it to the fuel tank. To ensure that the fuel in the filter was warmed, enabling SVO usage in cold conditions, I simply connected the spill line to the lift pump feed, so all warm return line fuel is recirculated through the filter and injection system. This also has the benefit of reducing the strain on the lift pump and preventing cross-contamination of the fuel tanks. It does mean that closer attention has to be paid to bleeding the system, as any air in the injection system will also be recirculated, now that it can’t be sent to the tanks, but in practice, that just means bleeding two or three extra times within a short period any time air has been introduced to the fuel system.

With all the fluids checked and the electrics completed, it was time to try the engine. With the fuel filter purged, the engine started instantly, and runs very smoothly. There is very little noise at idle form the exhaust, and barely a trace of white smoke just after starting. It should run very cleanly when run-in.