Okay so basically, this truck runs really rough at idle it a 1991 ford f150 with the 4.9l i6. Whe. I got it i didn't run i put new to me injectors from picknpull and the all work i think. But after puting them in i put new wires an plugs in it and then i thought mabye the fuel pressure regulator was bad so I put a new one on and it didn't change. One of my friends said to check the IAC and i did as far as i know if work good. So then someone on here said mabye it was the MAP sensor and wh. I unplugged it the engine stalls also when i inplug the IAC it stalls too. It sometimes has trouble cranking whick is weird cause it has a new starter, battery and starter sellanoid it also has a new clutch and throw out bearing. I've checked for vaccume leaks and thers none as far as I can tell. I took out the ecm and there were blown capacitors and resistors, I have replaced them with new ones, im really af a loss right now. Its not throwing any codes.... help plz.