Well it could be many things, can you describe what sounds its making when you try to start it? If you are really pointed in the fuel delivery direction then possibly fuel pump. They are common to fail and easy to replace.
Take exhaust and handbrake cables out
Drain the fuel the lazy way
Now release the plastic light weight tank without worries, just hold it with your hands. Make sure all connectors are off and the filling neck is unscrewed from the top too. Voila
Jet wash the tank inside and outside. Use brush to scrub like mad inside to remove the dirt that has gathered over the years. Keeps clogging the fuel filter in the future.
Throw away the old french mareli fuel pump and go make china great again (half price) http://www.ebay.co.uk/itm/391267855629?_...EBIDX%3AIT
tips: don't force any connections out with screw drivers etc, they are all press (like a button) and pull style.
Part number is 1525H8 http://i.imgur.com/XG4c6qA.png
02-07-2016, 02:45 PM
(This post was last modified: 02-07-2016, 02:47 PM by dumdum.)
If it's a com2000 variety ie a later lingo from say 02-09 then the fuel pump relay is built into the psf1 (passenger side fuse box aka the big board with twenty odd fuses behind the passenger side headlight) under the bonnet and isn't swappable by itself, it's a replace the lot job as its soldered in and potted, however I will add that I have only ever had wiring faults and power supply faults cause none running issues, never touch wood had a none runner due to a psf1
If it's an early one it'll be part of the double relay second stage which only kicks in on cranking and is negatively triggered from the engine ecu
Chances are you you have a broken wire or power supply/earth fault somewhere...