Hey thanks for coming back with feedback..
Fuel cap - I did replace mine about 6 mths back, with an 'equivalent' after mkt job, as I was getting a lot of fuel odour after stopping..particularly when full..and I actually found that fuel had expanded in the tank and was seeping [sp?] from around the filler...so i replaced it with new as above for to suit an Isuzu rodeo ute here in Oz...I still get a little odour when she sits in the garage after a run but much improved and seems to pretty much have fixed that problem.
Battery - was checked and replaced [3 days ago] as it was showing low voltage..apparently battery when car is running should show voltage of 9.5 to 10 [amps] or higher, the old one was hovering around low 8s...and as I said in the thread was 'lazy' when cranking to start..this same engine is/was used extensively [the 3.2L] in the Holden/Isuzu work ute here in Oz, and when i queried a local tuning shop that services 'heaps' of them..he said to me thats the first thing he'd check..

So so far with the new battery on board no 'light' and a nice positive crank to start..
regards