Type 8 returns a range reference so you need to use "Set V =" I added a bit of error handler too.
Option Explicit
Sub WoVbaAppInputbox()
Dim Myformula As String
Dim Formulacell As Range
Dim v As Range
Dim TryAgain As VbMsgBoxResult
Myformula = Application.InputBox(prompt:="Enter formula", Default:="=SUM(", Type:=0)
If Myformula = "False" Then Exit Sub
SelectAgain:
On Error Resume Next
Set v = Application.InputBox(prompt:="specify range", Type:=8)
If Err.Number = 13 Then
TryAgain = MsgBox("you didn't select a range, do you wish to select again?", vbYesNo + vbQuestion)
If TryAgain = vbYes Then
GoTo SelectAgain
Else
MsgBox "You do not wish to continue the code will now exit", vbInformation
Exit Sub
End If
End If
v.Formula = Myformula
End Sub