Antenna immobiliser-ring: Your Volvo P80 C70 / S70 / V70 starts then immediately dies/ stalls
A classic symptom for 1999 and 2000 models. Not sure if earlier models have this part. Can be the fuel-pump relay but nine times out of ten, it's the antenna ring for the immobiliser system.
The ring around where your key inserts. Take the 3 torx screws out of the steering column, pop the clamshell off, and remove the antenna ring. Clean up the contacts on the plug and reinstall and see if it works again. No? Order a antenna immobiliser-ring.
A proper sized can of Deoxit D5 or Inox MX3 is nearly as useful as WD40. For old contacts. Unfortunately not as cheap, but don't bother with the incy-wincy 5 & 10ml tubes. They are a false economy. Buy one large can, it will last you a lifetime.
Without Deoxit or Inox the fault will return. [Great on Scalextric or your model railway BTW]
Not Volvo related, but a very good demo how effective these products are:
https://www.youtube.com/watch?v=NnnSjyXyhrU
It looks faked. It isn't.
Deoxit D5 or Inox MX3, both are identical. Thye work as a dielectric, and prevent reoxidisation. I swear by them. Use on hi-fi, your laptop/mobile too. Works with your driver door window-switch cluster issues too. On cars of this age many plugs , contacts and connections go iffy. Used it on corroded bulb fittings for my trailer and on my dishwasher only last week.
Deoxit D5 or Inox MX3? 300ml. Get whichever is cheapest, but never the tiny tubes.