Intermittent Starting 300tdi

I seem to have an intermittent starting problem on my 1996 'N' registration 300tdi. Its manual transmission 2.5 tdi.

When going to start the car, it operates as normal. Glow plug light comes on and timers as normal. Then sometimes it starts no problem, but other times there is nothing. No attempt to crank, just a click/clunk. You can usually get it started by repeated attempts at turning the key

The battery is a brand new 019 type with 950cca, and it also has a brand new starter motor and alternator. All of which were fitted last week as part of the cars refurbishment.

The stop solenoid on the back of the injector pump seems to be wired into a 12V cable from the glow plug timer relay on the back of the fuse box. I don't whether this is normal or something that was done by the previous owner as it is just solder into the cable as it enters/leaves the relay

Is there anywhere best where I should start the investigation?

I've been searching on google and a common problem regarding non starting 300tdi's appear to be a "spider" wiring on the alarm?

Also, does anyone know whether the this starting issue would affect an MOT, as its booked in tomorrow

Many thanks

Ade

Dicky immobiliser. Do you get the red landy with a key show on the dash??

Have the same on mine especially if I've sat with the engine off and key in for a while without doing nowt. Have to either press the fob or try and start him a few times then it catches.

Irritating but I'm a bit lazy to sort it and it don't really bother me.

Is it a auto ??

check all your earth connections are clean and tight