The generator matrix

 1  1  1  1  1  1  1  1  1  1  1  1  1  1
 0  4  0  0  0  0  0  0  0  0  0  0  0  4
 0  0  4  0  0  0  0  0  0  0  0  0  0  4
 0  0  0  4  0  0  0  0  0  0  0  0  0  4
 0  0  0  0  4  0  0  0  0  0  0  0  0  4
 0  0  0  0  0  4  0  0  0  0  0  0  0  4
 0  0  0  0  0  0  4  0  0  0  0  0  0  4
 0  0  0  0  0  0  0  4  0  0  0  0  0  4
 0  0  0  0  0  0  0  0  4  0  0  0  0  4
 0  0  0  0  0  0  0  0  0  4  0  0  0  4
 0  0  0  0  0  0  0  0  0  0  4  0  0  4
 0  0  0  0  0  0  0  0  0  0  0  4  0  4
 0  0  0  0  0  0  0  0  0  0  0  0  4  4

generates a code of length 14 over Z8 who´s minimum homogenous weight is 4.

Homogenous weight enumerator: w(x)=1x^0+91x^4+1001x^8+3003x^12+24576x^14+3003x^16+1001x^20+91x^24+1x^28

The gray image is a code over GF(2) with n=56, k=15 and d=8.
This code was found by Heurico 1.16 in 1.12 seconds.