Can Any one help please

try taking the fuel line off at the tank and pocking a wire down it ,years ago I had a similar problem it turned out to be a small bit of rubbish stuck in the internal pick up pipe , now and then it woulld act as a butterfly valve and stop the flow ,it all depended on how much fuel was in the tank ,it took ages to find after almost replacing the whole fuel line .

Have you got all your facts right?

1998 TI could only be a petrol 4.5....

TI spec was never available in diesel, then again 4.2 TI petrol was available until 1997 and it was GQ....

Snatchem,
Check if it has a filter near near the fuel tank I had the same problem with an MQ I used to have.
Cheers

yeah check the fuel filter/ lines and tank. speaking of stories, when i was at holden we had the local boys in blue bring a new ss chaser in for work, had a bad miss when going hard under full load. very embarrasing for the hot shots to be passed by the cruisers when in a chase lol. So i'm in the seat driving with the boys alongside and we go for a run, sure enough top of third into fourth bam breaking down , back off, power again , same thing. couldnt top 140. They usually do 220 or so (so i've heard hehe). Anyway all diagnostics came back normal, so i drop the tank and remove the fuel sender/ pump assembly - all normal. Then by accident i shine the torch over the tank opening and something catches my eye. One Dirty big rag.. under constant hard accell the fuel pump has no return to the swirl pot and pulls full amounts from the tank, sucking the rag into the pickup and blocking the flow.. No explanation how it got there- it just was...

Ok sorry it is a 4.5, and Magic Nissan could have found the problem today as they found a strange wiring harness attached to the harness going to the computer. Some one (previous owner) has disconected something maybe sat nav and looped wires back into the plug and taped it all up. Here's hoping...

thanks everyone for your help

Snatchem