my car pops mostly when its cold under a load sometimes it will run for an hour before its runs fine sometimes its in 10 mins if i push the clutch in revs up fine or get on the throttle hard it goes normally i did a mass air conversion but i dint do the 2 optional things the fuel signal wire and and the speed sensor wires ive changed the whole distributor and its not the problem i cant find any vac leaks or here any its idles pretty normal all the time it has stalled a few times on it own anyone know what it could be thanks