weak spark on plugs

[reevio]

im running a single coil pack and the spark isnt great ,when the cars cold it starts fine but once warm and i go to restart very hard to get it to fire up ive removed plugs and tested spark when hot and its very small or nothing atall its a second coil and a new set of plugs weak ground as my battery is in the boot with a cable grounded to the chassis any help much appreciated

[Sprocket]

should be easier to start a hot engine. Are you sure its spark and not poor crank enrichment settings when warm?

Have you checked the spark with one of these?

http://www.etoolcart.com/gunson-flash-test-ignition-tester-g4079.aspx

[reevio]

gunnis been round a couple of times had a play around but not as easy now as hes moved further away from me if you like ive got a log on idle if anyone wants to take a look whats the best way to post up a log and no not checked with a spark tester the good old fashion plug out on top of the engine job

[rob@vems.co.uk]

Could it be that the coil is old and buggered?

[reevio]

its the second coil the first one blew 2 drivers on the ecu gunni had to repair it or i think thats what happened