On Friday the postman finally delivered the last components I've been waiting for to build my transmission controller. I assembled it on Friday night, and plugged it in on Saturday morning.
It worked! I could manually select all four gears, and when placed into auto it would select first. I did a quick trip up and down the street, and everything behaved as it should. Unfortunately the alternator that was on the engine was dead, and I've been waiting for the replacement to arrive, so I couldn't go far.
Today I fitted the replacement alternator, and after confirming that everything was good, I worked up the courage to take it for a drive around the block (around here, the 'block' is about 6km, and phone reception is patchy). The engine was warmed up, everything was behaving itself, so I hit the road.
The drive starts with a very steep ascent for about 600 metres. The car had plenty of power to accelerate up the hill, and I soon shifted to second gear. It continued to accelerate. I shifted into third gear, and it maintained about 40km/h up the hill. My concern was that the small diesel wouldn't have the power to shift the weight of the P38, but that has proven to be completely unfounded - it easily matches the V8 for low RPM performance.
After that, the drive is much more sedate, a few undulations and just one significant uphill section. The car cruises effortlessly in fourth gear at speeds as low as 40km/h, and pulls away smartly. Gear shifts are smooth and prompt. Coolant temperature remained steady.
I encountered my first issue at a stop sign. I have to revisit my code in the transmission microprocessor - the torque converter failed to unlock, so the car stalled when I brought the car to a stop. However, the car restarted immediately after placing it in neutral, and the rest of the drive home from there was uneventful.
I'm really happy! Definitely some improvements to be made to the transmission code, but other than that, it felt great. There are some vibrations through the body at idle, but when you're moving along they're not noticeable. There is less engine noise in the cabin than in my 406 with the same engine, although with the bonnet open the engine in the Range Rover is a little more 'diesel-y'. I suspect I haven't got the crankshaft position sensor in exactly the right spot. But the engine doesn't seem to mind, it pulls great.
The only other thing that there is left to do is to plumb up the water side of the water-air intercooler, to achieve the maximum potential of the engine, and tidy up some wiring in the engine bay. Down the track I will re-instate a cruise control, but I haven't decided yet whether I'll recomission the cable-operated Range Rover system, or rewire the switches directly to the engine ECU, which has a cruise control system inbuilt.
I will also get a torque converter rebuilt, as the splines on the one I have fitted at the moment are very, very worn, and I feel that the torque of the diesel - being significantly higher than the torque converter donor vehicle - will cause the splines to fail quickly.
I will sleep well tonight
