[redbeard0531]

<edit>Removed stuff covered by people who replied faster that me.</edit>

Here is what I suggest.

GoSub Fire3:

Fire3:

count Var word 'Number of 26ms periods
Fire3On Var Bit ' 1 if the piston should fire

If p2_sw_trig = 1 then Fire3On = 1

If Fire3On = 0 Then DontFire:

If count < 3000 then
relay1_fwd = 1
count = count + 1 + delta_t
Else
relay1_fwd = 0
count = 0
Fire3On = 0
EndIf

DontFire:

Return

That is how I would do it, but it may not be exactly what you need.