1 wire alternator help

Hello i am new to the forum and was hoping someone could hepl me out with what seems to be an electrical problem on my 87 lx. Car ran great after
My h/c/i swap but stock 75 amp alt could not keep up with my electric fans. On went a 140 amp 1 wire powermaster 1 wire, and now it bucks and pops like crazy. I Ran a 4ga wire from alt to cutoff switch in the hatch, and 1ga to batt and back up to solonoid. Sound right? Run like this its popping and bucking above 2000rpm, like the ignition is shutting off. Also it melted the contacts in the solonoid causing the starter to stay engaged. Puts out 14 v at idle.Putting the stock alt back on eliminates the prob. Prob shoulda got the highly recomended 3g .Any help or suggestions are greatly appreciated

Thank you for your responses. The Powermaster i have is a 2g style 1 wire. From what ive been reading i need to put 12v to the yellow/white voltage sense wire, and the green/red ignition wire, as only the 4ga (with megafuse) wire comes off the alternator back to my cut off switch, hence the "1 wire hookup". Powermaster's instructions say nothing about this, even though its a vehicle specific peice. I suppose thats why when i put the stock alt back on and plug it in, the car runs like a champ. Again, i appreciate the help, and your 93 gt looks sweet! Ill have to put up a pic of my lx.

I should have realized with no power to the the red/green ignition wire i was running only off a half dead battery, without enough juice to fire all cylinders above 2000rpm. Waiting on my new low mount alt. bracket to come in before i can try