Description
fuelpump only works when starter engaged

Explanation & Answer

fuel pump wouldn't have anything to do with the starter or battery. Start with the simple stuff and work you way up. check your cables for corrosion and snugness. check the wire(s) on your starter making sure they are tight and take a volt/ohm meter make sure you have voltage to the starter. check any secondary grounds. so on and so forth and hopefully you don't make it to the ignition. good luck.
