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Speeduino – Rover SD1, A Rather Large Update

Gather ’round children, let grandpa Kelvinator tell you a story.

It was a warm summer’s day….

Well yeah, it’s been damn hot recently, and since my last update I have been working on the Rover every single free second. This is going to be a long post in order to catch up on what I have done.

Having the loom basically laid out, I took it into the house and began to wrap and sleeve the wires. I’ll tell you now, braided sleeving is a bit of a pain to do. It’s very time-consuming, it’s hard on your hands, and not much fun. When I had mostly sleeved the wires, and wrapped various parts in self amalgamating tape (which in contrast is awesome. Its a strong rubber tape that sticks only to itself, and doesn’t leave any horrible residue like insulation tape) I quickly laid it over the engine and cut the wires to length.

In order to wire in the injector resistor pack I needed to somehow obtain the weird plug. I sourced one from a Jaguar a while back, which is an exact fit, but unfortunately as the Jag is only a 6 banger, it was missing two injector feeds. I didn’t want to, but I couldn’t find the weird little female pins it uses by themselves, so I had to de-pin and cut two off my spare SD1 loom.

With the additional wires

That was the final piece in the plug finding puzzle, so I started assembling the loom and adding all the connectors I need. First up was the JPT injector connectors.

These are proper sealed connectors with seals and boots. To actually crimp them properly you really need a proper crimping tool. I picked up a ratcheting tool and the correct dies from Aliexpress.

It works mint.

The boots are bloody hard to put on though, but the plus side is that they won’t come off in a hurry.

I used the same crimping tool to assemble the TPS waterproof connector

Injector connectors

Once all those connectors were in place, I took same brave pills and cut the loom in half.

I needed to add in a pair of large waterproof connectors in the engine bay so I can split the engine and interior sections in half. It was a lot of crimping, that’s for sure! Because I needed two connectors, I used opposing connectors so they cannot be incorrectly connected (both sides of the loom have both a male and a female connector).

This is the half of the loom that goes into the car through the firewall

With the main connectors fitted, I refitted the engine harness once and for all, and reinstalled the plenum.

You may notice in the last photo that the TPS is missing. I took my original one off because I was loath to cut the plug off and ruin my perfect working original one. I remembered that I had a spare in my boxes, with the connector already missing. I figured like mine before I fixed it, this one was probably suffering worn tracks too.

I opened it up, and sure enough it was badly worn. I wanted to try fixing it anyway, but it looked pretty bad, a lot of the track was missing.

In comparison, this is my one that I fixed

I trimmed off the wiper, and used some quick-setting super glue to move it slightly.

Unfortunately during testing after my repair, it failed my tests. There just wasn’t enough good track left to save it, and the wiper couldn’t make a perfect clean sweep.

So once again I was thrown into “Plan B” mode. I purchased a new Wabash generic rotary sensor a while back, as with some fettling a couple of other SD1 owners have managed to fit them and then they had a nice reliable, easy to source, replacement. Fitting this takes a lot more work than just changing the plug, so I initially wrote it off as too hard for now, but now I didn’t have many options. Cut the plug off my good original TPS, or make this one fit.

I made it fit.

I started with the bracket the original TPS mounts to on the plenum, and traced around it and through the holes onto some scrap aluminium plate

Good old coping saw came into play again. That thing really gets my “tool of the year” award.

This is the sensor

Test fitting the plate

It needed to be spaced out from the plenum in order to fit the screws that hold the sensor to the plate. A test fit with the sensor in place was on the cards

Two things. I don’t have any photos of the finished product, but I did end up painting the plate in low gloss black like everything else, and if I were to do this again I would use the sensor that has the flying leads instead of a connector. There is little to no room between the sensor and the two throttle body coolant hoses for the plug. I did make it fit, but at some point I might just end up looping the coolant hoses and doing away with them.

With that in place it was finally time to get the interior loom in place and test fit the Speeduino.

With the Speeduino wired in I tested the cranking, and sure enough the coolant temp sensor (once calibrated using Ramons specs), intake temp sensor and most importantly, the crank position sensor all read correctly. I did have an issue with the TPS reading backwards though, but swapping the Vref and Ground connections sorted that issue and the new TPS calibrates perfect.

I couldn’t try starting the car though as I was missing one kinda important thing. Ignition leads. Because I was ditching the poxy distributor and going for custom coils, I needed to make a set of leads as an off-the-shelf solution doesn’t exist.

I purchased a universal lead kit out of the States made by Pertronix. I got the kit to suit the GM LS engine, as they use the same coil terminals as the VW coils in using. They also have 45 degree boots (I wanted 90 but couldn’t get the perfect combo).

All the leads connected to the spark plugs on the Odd bank of cylinders, as I ran the wires to gauge length

With the leads roughly in the place they will be when running, I took them off one by one, cut them down and added terminals and boots.

I got a flashy MSD crimping tool for the job, that you use in the vice, but it really didn’t work well for these terminals. It had a habit of crimping one side down and only bending the other slightly. I had to finish the crimp with pliers. It had a good cutting guide though, for stripping off the insulation without cutting the core.

First four leads done

The now useless distributor cap is in the way, but at some point I will either buy or make a Dinky Dizzy to replace the whole distributor, but keep the important oil pump drive. I’ll need a donor dizzy from a later RV8 if I want to make my own.

Dinky Dizzy (Photos courtesy of Megasquirt V8). It’s really just a full distributor cut down above the bearing, with a cap on the top to keep dirt out.

And all the leads installed

The current mess under the dash. It works, but it’s ugly (for now)

The plan is to take the interior loom and Speeduino out again, so I can add plugs on the ECU side and mount the Speeduino in the housing. That will tidy it up a lot.

Today was the day. I have been having some issues with the fuel pump not priming, and the coils not being configured correctly, but it seems like at least for now, its working.

This happened when I turned the key for the first time with everything connected

I needed to check the static timing, so with a timing light and lot of cranking, I wound it back from 200 degrees ATDC, and ended up at 157 degrees ATDC, where the TDC mark was sitting right under the pointer. Woo.

With the timing now correct, I tried it again

For almost zero tuning, and with the cranking advance incorrectly set to 0 degrees (forgot to change back after checking timing), it actually started and ran really well. Responsive, and pretty smooth. Idle is high, but that’s to be expected (I had to increase it heaps when i got the car, and the rocker cover gaskets wouldn’t be helping in the state they were in).

Unfortunately it wouldn’t be my car, or British, if it didn’t choose to celebrate in its own way….

Apparently the auto trans pump made enough pressure in that short run to rapidly eject a bunch of fluid from the (blocked off) cooler hose when I shut the engine off. Ah well. I plan on servicing the auto anyway, lol.

So that’s where I am tonight. The car starts and runs. Great success.

Next up is installing the radiator and fan, then jacking the car up and pulling off the exhaust so I can fit the wideband O2 sensor. Been putting that off, there is an awful lot of coolant and now trans fluid under the car.

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steven tomkins
steven tomkins
6 years ago

hi dont know if you can help my sd1 vitesse has had some new injector caps fitted at some time and i would like to just make sure the wires are on the right way round on the injectors . if looking at number two injector from the drivers side i have the live wire from the resistor pack going to the left hand side of the connector any help thanks steve