Thanks for your reply Bruce you are right about the Gremlins. I have Replaced F.I relay and resoldered R.S.and tried swapping with Fan relay have Cleaned all connectors and cleaned the R.P.M sensor all wiring looks good but I have not been able to undo the main loom connectors they won't budge have given them a good soaking with contact cleaner grounds appear to be OK. I have not yet tried Starting with the A.A.M disconnected will try next time engine cuts.
When the engine cuts, the spark looks good and there appears to be fuel prssure in the rail, Soo if the injectors are operating ? it should start. I am told by Volvo dealer here that I have very limited diagnosis checks available on older model cars.You mention checking fault codes in the computer are you able to tell me how to do this please.I have mannaged to obtain the 5280 Fault test diode device and am running with that plugged in as shown in the F.A Q pages
but apart from glowing when I switch the Ignition on it does nothing whilst Iam driving "as yet".Given that the engine starts after a 35-45 minute wait I am assuming "rightly or wrongly" that some component has overheated and short-circuited, and needs to cool off coils will do that but mine still has a spark
when the engine stops. In the F. A. Q page someone claims that the R.P.M. sensor will act in this way,Do you know whether this is correct, if it is then this could be my trouble. I am told that a replacement is around $300+.
Thanks for your interest will go gremlin hunting once more