car wont tick over

i bought a mk1 with a kr conversion init when i bought it the previous owner said the cold start had gone thats y it wont tick over ive changed this part and still the same anyone got any advise in what my problem is thankyou all

does a 16v have an Idle Stabilisation Valve like the other later gti`s? thats normally the problem on them with tick over and stalling problems, its usually located just in front of the rocker cover on an 8v, not got much experience of the 16v set up but i guess its simmilar