I have a 94 pickup 22re. Sat for 4 years and my son wanted to get it going. Mice ate most of the wires. Replaced the wiring harness on engine. Would start but when warm is would start running very rich and stall . Took to shop. They replaced fuel pump, filter, and spark plug wires and plugs. Will not give code.I replaced the IAC valve as that was why it was originally parked. Now I cannot get it to idle over 500rpm even with idle adjustment screw and it runs very rough and smells very rich at idle. If I keep the throttle at 1000 rpm it runs reasonable with only small miss. If I drive it then it works fine with good power unless I let it drop to idle. I am going to replace the main air sensor and TPS? May replace injectors. I don’t know what else to do if it won’t give a code. That is why I’m asking the question here. Shop was no further help and doesn’t seem to want to work on it. I’m willing to dig into it but don’t know what direction is best.