1995 2.1td SX Auto Project

[Dieselman]

Make sure the diode in the relay unit is functioning properly and has continuity in one direction.
Check there is power being supplied to the relay via F3 in the engine bay fusebox and the relay has a good Gnd.
Does the lamp go out when you trigger the relay manually?

If the controller isn't pulsing the relay, then it has to be a controller, or power input issue.

Nice strip-down of the diesel pump, all the way to the vane pump. You can replace the metering head O ring without removing, or dismantling, the pump; simply remove the injector pipes and loosen the metering head enough to sneak the O ring out and a new one in.

Always make sure your (wheel) nuts are done up tight enough. It will always be the front left comes loose due to the bolts being Rh thread.
I always leave the covers off until torqueing the bolts. 90Nm for Xm steelies, 100nm for alloys.

[josh2109]

Make sure the diode in the relay unit is functioning properly and has continuity in one direction.
Check there is power being supplied to the relay via F3 in the engine bay fusebox and the relay has a good Gnd.
Does the lamp go out when you trigger the relay manually?

If the controller isn't pulsing the relay, then it has to be a controller, or power input issue.

I've double checked my work today, the diode is good. I've got power and earth at the pins which they should be present on throughout the ABS system.

However, I've done more testing of the wires from pins 19 and 8 on the ECU, which go to the relay coil. I was measuring about 2.5v at pin 3 on the solenoid end of this loom - obviously not right. I then unplugged the ECU, and I was seeing this voltage rise to 4.5v. I can measure this at either pin 19 on the ECU connector or pin 3 at the solenoid connector. On pin 8 at the ECU connector and pin 2 on the solenoid connector I am reading 2.5v

Considering that the wiring diagram shows these as direct wires with no other splices, the only conclusion I'm coming to is that the loom must be damaged somewhere and I'm seeing a short between these wires and other circuits.

I've removed most of the loom and will start stripping it back and checking it over the next few days.

Nice strip-down of the diesel pump, all the way to the vane pump. You can replace the metering head O ring without removing, or dismantling, the pump; simply remove the injector pipes and loosen the metering head enough to sneak the O ring out and a new one in.

Thank you - I did strip it to a bare housing, but forgot to take a photo of this stage. I actually found it very enjoyable to strip and rebuild, I like jobs like that, I'd happily do that job again rather than continue to work on the ABS wiring.

I did consider swapping the o ring in the way you suggest, but I've had a series of leaks from this pump and decided that it was for the best to swap out every seal for new. I was already doing the timing belt, so it wasn't much extra work to remove the pump.

Always make sure your (wheel) nuts are done up tight enough. It will always be the front left comes loose due to the bolts being Rh thread.
I always leave the covers off until torqueing the bolts. 90Nm for Xm steelies, 100nm for alloys.

I do the same as you - I only put my wheels back on when I have the torque wrench at hand, and fit covers once the nuts are torqued. what went wrong here was I pinched the first bolt on the outside of the seat on the steel wheel by hanging the wheel from it when struggling in the dark, and it didn't self centre as the others went on. The first time I checked it, there was no play in the wheel or the bolts, but I took it for a couple of laps of the block (it's a dead end here, so quiet and mostly safe) and then as you rightly predicted it was the front left wheel that gave the game away; a couple of the bolts backed out slightly at this point. I have one of those threaded rods for seating wheels that use bolts, so I've now made myself get into the habbit of using that rather than trying to hold the wheel in place with one hand whilst threading bolts with the other and swearing.

Looping back to the subject of hard/slow starting, I've now replaced the negative battery cable, added a relay to the starter solenoid circuit, and I've replaced the glow plug wiring with suitable wire. The car still struggles to start, despite cranking healthily now. I guess the last place to look is the pump timing - I've started playing the game of tweaking the pump back and forwards earlier today, to try and see if I can improve it. I will double check the fuelling adjustments on the pump too, just in case.

On the subject of electrics, I note that even with the starter solenoid circuit interrupted, the colling fans run when I put the ignition to the 'start' position. That's definitely not right! I was thinking a bad earth at first, but if I'm breaking the circuit to the solenoid and it isn't being energised then that's now leading me to believe that there's a short in the loom for the fans somewhere. I also can't help but wonder if this is related to my issues with the ABS wiring.