Escape

You can't really select 4th with the ZF in the D2, you can only allow the ECU to shift up to 4th if it thinks that is the correct gear. Are you sure you're not in 4th? Revs too high could also mean the lock-up isn't engaging. Best test would be to take the car up to speed, let it shift through the gears in D and when it should be in 4th move the lever to 3rd and watch the revs. You should first see a notable increase in revs and then a small drop, as the lock-up engages in 3rd. Once you can confirm the problem, I'd start by looking at the oil in the autobox. Maybe it would benefit from an oil and filter change. Filip

Simon, I'm well aware that the P38 was state of the art in it's time. And it took the competition many years to try and catch up. So I'm not really serious about simplifying everything. 😉 The whole reason I'm using a P38 for my project and not a Classic is because I've got used to all the creature comforts. And the extra space, not to mention the absence of rust. 😛 But on the other hand, I like my cars simple as in not too much electrickery that thinks it can do a better job than the driver. Hence going to all the trouble to convert to manual. I'd prefer a little stick for the transferbox as well, but that would likely end up a serious bodge job. At the cost of the nice interior layout. So the all-relais alternative for the ECU seemed like a good alternative. As for the HEVAC, I don't use or want all the auto features, I'm very happy with basic controls like in a Defender or classic Lotus: temperature (without feedback), distribution and fan speed. So next time an HEVAC module fails and leaves me too hot or too cold, I might just look into manual control for the blend motors. The windows can stay, complete with one touch comfort function please. 😉 Greetz, Filip

Could be a bad connection, that is only noticeable as revs/vibrations increase. Always a good idea to check all cables before replacing parts. 😉

^^ what he says. Check the output from the ECU with diagnostics, if that's OK look at the wiring and last resort the dash itself.

Yes they did! Instead of a nice sturdy little gear lever, you get a button (manual) or an H-gate (automatic) to politely ask a computer to change range for you. If all conditions are met, the motor doesn't bind and the position switch is in good order, it will do so. To be fair, usually it works OK, but is the ECU fails, there is now an easier alternative. 😉 Lotus claims the electric windows fitted as standard to the Elan +2 (the first Lotus so equipped I think) were no heavier than the manual winders. I wouldn't mind winders, less to go wrong, but I must admit it's easy to be able to lower the passenger window from the driver side. Especially when using a RHD car in Europe, where everybody walks up to the wrong side if they want to talk to you. 🙂 Filip

I think the improvement in brake feel might have more to do with the cars and braking systems evolving over time. Especially the Range Rover, as top end of the range. As for the P38a system, the wiring is actually rather simple. Rave lists it all, including the diagrams @elbekko posted earlier. All the valves have their default state to allow normal operation of the brakes. The hydraulic booster has it's own wiring, with a pressure switch controlling a relay, independant of the ABS ECU. It was all designed (and rightfully so) to allow as much functionality as possible even if a fuse blows or the ECU fails. So using it without the ECU shouldn't be a problem. You could even wire the low pressure warning lamp to work without the ECU. Filip

Some cars (like old BMW 5) came with a hydraulic brake booster, but without ABS/TC. It doesn't really matter what is used to assist braking, either vacuum (engine or electric) or hydraulic pressure. You could fit the pump, accumulator and master (with the complete valve block) of an ABS vehicle but not use the control unit. That would give you brake assist, a fail safe system but no ABS or TC. It would be a lot of work and probably not cheap unless you have a donor vehicle. If you're not happy with the brake feel, why not use an electric vacuum pump instead of the engine vacuum? Easier to tune to your desire and independant of engine revs. You could change the master and/or add an adjustable pressure regulator to the rear for even more flexibility. This is exactly what is being done to some Lotus Esprit when the first generation ABS system starts to act up. With very good results. Filip

What did you do to fix it? Bad connection somewhere?

I can confirm, the later covers have the oil feed directly to the bottom of the pump. And the camshaft is shorter, it just reaches the sprocket with no 'nose' for the dizzy drive gear.

I find the Bilsteins too hard on the Range Rover on anything but good roads. But might be just what you're looking for on a lifted Defender for road use, to reduce sway.

That's indeed correct! David, if we ever meet, you've earned yourself a Belgian beer. 🍺 Ben helped me design it, many moons ago, so he wasn't allowed to guess on here. 🙂 I've had a few ECU's fail and as the ones for the manual are harder to find, I decided it would be nice to just build a simplified control box. Tested in a car today and everything works, including the messages on the dash. Only problem is the non-latching switch in the manual cars, but that's easy enough to replace. I'll be using a bunch of Carlings instead of the original switches anyway. I still need to add something to select neutral as well but haven't decided on using an extra switch instead of faffing about with fuse 11 (as standard). As for fuses, the relays and cables should be able to handle the fused 30A without any worry. I could always replace it with a 20A fuse, just to be safe. The problem in the early ECUs was the prolonged high current through the power transistor if the motor stuck. With limited cooling they soon gave up. The relays wont have this problem. Now, on to the HEVAC... Greetz, Filip

@Elbekko would like that, a simple controller for the HEVAC! Temperature should be easy, just a mom-off-mom Carling switch to control the blend motors. You could do the same for the distribution, but you'd not have the info about the actual position selected. Might just give it a try. 🙂 That would be several small plugs, not the one big black one in the picture. This thread was meant as a little fun, now I'm ending up with ideas for yet more work. 😄 As long as we get some laughs out it. 😉 Filip

Do the intermediate serp covers have the oil pump on the crank, instead of on the dizzy drive? Never knew that.

You got it! After all, you only need wipers and lights right, everything else is just added weight. 🤣 If only I could... It's something a lot more basic (and unnecessarily complicated in the P38), but I'm still proud of it. An EAS replacement would be nice (I've seen 2 driveblocks fail on customers cars recently), but to read the height sensors would require something more complicated than a relay, and that's beyond me to design/fab. Alarm/central locking is a good call as well, as it's basically a simple system with just a few microswitches. But incorporated in the BECM, so possibly a can of worms once you start tinkering. Anyway, not much left now, is there? 🙂

Getting very close. 🙂 Obviously a P38, it's for my project (the one sitting on the lift for the past year or so...). But not the gearbox, it will be a manual. And I think 3 relais wouldn't cut it to give decent control over the autobox. But an interesting idea! This controller is to replace an ECU that's more prone to failure than the one for the autobox, especially on early cars. @Simon_CSK that's not sad at all, it just shows how knowledgeable we are about these cars. 😉 Which is also why forums like this are so helpful, those in the know often only need a reasonably accurate description of an issue to be able to identify the cause and a possible solution. Filip

Not the engine, though that is a very similar plug. The engine side will be handled by MS, with the usual D37 plug. There's another ECU that can be replaced by just a few relays.

Which ECU? There's quite a few of those. 🙂

Can anyone guess what this little bit of electrickery does? I'd worked out the schematics years ago, the lockdown meant I finally had time to put the prototype through the test. Took a bit of time, but in the end it works as expected. 🙂 Filip

Those symptoms are indeed typical of low voltage. Normally, all faults should clear when the cause is fixed. But as you've driven the car, it's possible the EAS and ABS have gone into hard fault. Best to get the codes read and reset and try again. Have you tried the car since? Worth a try to disconnect the battery, give it a proper charge and then reconnect everything. Filip

The higher torque at lower revs is indeed due to the longer intake runners. At the cost of a very little bit of top end power. The Bosch sequential injection was for emission purposes, to comply with Euro3 and similar.

That's the one I meant. Couldn't find a part number either, but the part definitely exists.

The wires are all white from C0789 (or C806 on <99 cars) on, as those are accessible from the outside (in the loom between the body and tailgate) and could pose a security risk. The other connector, coming from the right body harness, is color coded. 😉

The wire diagrams are in RAVE, that's the easy part. But both the Disco 2 and P38 Thot use an immobiliser. The BCU or BECM has to provide the correct signal to get the engine ECU to start working. There are kits to bypass the security, but might be cheaper to just fit a MegaSquirt, especially if you don't have an ECU, loom and all sensors to go with the engine. Also worth noting the Bosch injectors operate at higher pressure (3.5 bar) compared to older LR EFI systems (2.5 bar). Filip

If it's leaking at the connection, a new O ring can only help. Maybe at some Loctite 577 or similar to fill (small) kinks. Or even liquid gasket. I wouldn't trust tape, I can't even get it to seal on water pipes half of the time (but that's probably just me 🙂 ).

The motors have a rotational potentiometer in the gearbox, so the system should be able to work out the position of the flaps. You can force a calibration cycle with diagnostics, sometimes that's enough to get them going again.