Hi Trefor, thanks for the reply.
Its fitted to a Nissan Almera N16 with the YD diesel engine Y reg, and old car, which responded to some tlc and a service very well, and which the lad used to get to work. In traffic one day it spluttered and stopped, so he waited a little while and restarted the car. It made it to nearly the top of the hill and stopped, with the mil light now on.
It was towed home and checked over, fuel to pump and fuel arriving at the injectors. The engine runs on cheapo easystart so the engine itself is ok, with the cam timing etc. being fine.
The pump was removed after diagnosis via the mil light, and, after making a special tool to keep the pump sprocket from disappearing down into the engine, and engine out job to fix !
The on board self diagnosis via the mil light says spill circuit fault. I know that the tranny in the pumps electronics that powers the spill solenoid/electromagnet has a habit of failing, overheating as its fuel cooled. This pump is fitted to various other vehicles, and I was hoping the spill solenoid was a reasonably common part.
The electronics has a good chance of being repaired by a firm up north, who only require the electronics part, meaning that the wires to the spill and stop control solenoids need to be cut. This has allowed access to the wires so a continuity check was made, all good so far.
I would like to know the resistance values of these parts, as the spill solenoid has a very low resistance, meaning it may be burnt out ?
The stop solenoid has a resistance of about 5 ohms measured, which seems about right ?
If the spill solenoid has burnt out, this may have caused the tranny to fail and take out the micro processer as well ?, or visa versa.
If that is the case then a "new" pump will be needed, which will require "matching" to the cars ecm.
The wires from the car ecm to the pump have been checked for continuity being ok. I will be making some "break out wirers terminals" in the engine compartment close to the bulkhead, so values and signals from the ecm to the pump can be seen on a scope, so at least I will know some hand shaking is going on. The other possibility is a bad connection at the ecm and/or pump, again hopefully fixable via the breakout wires terminals and some terminals at the pump. The pumps pin out is visible now and the terminal pins getatable, only needing some terminals that will fit the pins.
If all this fails and we cannot get a pump at a reasonable cost, the car will be scrapped and our love affair with a Nissan will be well and truly over, for ever.
We should have got a VW, but nothing was available locally at the time.