1.6D glow plugs relay?

[ilMamo]

Hello from Italy and sorry for my poor English!

Last year my 1981 1.6 diesel westfalia died on the highway. I think it was the relay in the engine bay that stopped letting the diesel pump from doing her work. We rebuilded the engine and changed the relay.
After 5.000 trouble free miles, the van is sometimes behaving weirdly:
- once the engine died stopping at a traffic light (fortunately it started again immediatly);
- when I turn the ignition key the glow plugs light comes on normally for some seconds but sometimes the starter motor doesn't turn;
- last week i took the van for a ride and it went perfectly for 20 miles or so, then I parked. After half an hour I came back to the van, turned the ignition key and the glow plugs light started to "flash" (was wobbling like a bad contact), the relay in the engine bay buzzed and the starter motor didn't turn. After some knocks on the relay it started perfectly and since then is working fine.

I've already bought a new relay, but I'm not sure it's the problem..

Any guess? I need a reliable van because I've a 4 months baby and my wife is going to kill me if we stop in the middle of nowhere during holidays...

Thanks!

[kit]

Could it be the battery earth?

[ilMamo]

Could it be the battery earth?

Do you mean the connection between the relay and the battery/ground?