still intermittant starting issue

well, I switched out my latch relay and I am still getting the same intermittant problem with my 87 4.0. Usually it will run great, but ocassionally, like it did this morning, the engine will just keep turning over and not catch until I pop the hood and unplug/replug the IAC. The IAC was replaced this summer with a brand new part, all the ignition connections and so forth are good but, its just the odd time that it just won't catch. I also make sure that I cycle the fuel pump a few times to make sure its getting fuel.

are you sure your disconnecting the iac and not the cps wiring harness. if in fact it is the iac, take it out, clean and inspect for proper operation.

the wires I am disconnecting are right on the IAC, the plug snaps in to the IAC, if i unplug it with the key on and plug it back it, she will catch, otherwise she just cranks and cranks.

It sounds like you need to clean the connection that you keep unplugging .

Check the wiring for damage