Fuel pump relay chattering

Ok, here on for the books, my 1996 Lumina PD (132K)has been acting weird lately, it will sound as if the car wants to stall, but the auto idle cranks it up again. While this is happenning the relay that contols the fuel pump chatters, like a door buzzer. Now I've done the usual, change the relay, cleaned the contacts into the fuse box, cleaned the fuses, and their contacts. Still does it very intermittantly, and seems to happen more when the car is cold. Is that relay controlled by the PCM, if so I have a spare which I'll change out next. Any ideas?

yes, it is controlled by the pcm. what i would do is take a look at the relay. find the controll terminals, the ones that are shown coming off of a coil of wire on the top of most relays, and then follow them back. one should go to ground, and the other should go to the pcm. check for cracked wires, loose or corroded grounds and bad terminals. if nothing is found, is safe to say the pcm is on its way out.