IAC problem getting worse

OK well my problem with the IAC is getting worse, I have tried cleaning the connection and replacing the latch relay. I think the old latch relay was good though because it was still starting the fuel pump. Unless I manually unplug and reseat the connection for the IAC, the engine will crank and crank and never start. This used to be an intermittant problem but its constant now. Its gotten really cold too. One thing that I wonder is weather the issue may be totally unrelated to the IAC. Its looks like almost textbook bad CPS/TDC issue, except its the IAC I am unplugging not the CPS. Appreciate any help on this.

Edit: Its an 87 4.0 AW4 by the way.

Have you actually removed the IAC and cleaned thoroughly? It may not make a difference but it's worth a try as it doesn't take very long. If it doesn't start and disconnecting the IAC allows it to start, replacement of the IAC may be necessary.

I haven't pulled the IAC yet or tried to clean it. Can you do that because I never even thought of that because I figured it would be too easy to get the pintle out of adjustment. Usually on a hot start it works better but its becoming pretty random. I can remember a few times it doing this after a hot start, but that was on the old IAC. What I am wondering is, by unplugging/replugging the IAC could I somehow be reseting the computer which is masking the actual problem which could be the crank sensor. I have heard stories from guys on the trail who have a crank sensor go out on them and just unplug it and plug it back in. Needless to say this isn't going to do much to make a broken sensor function but from what I understand it does somthing to the Renix ECU that lets the engine start.

remove the two little torq screws-
pull the IAC out backwards- try not to hurt the gasket.
take some gas- or tolulene-whatever, and clean the pintle off-
(remove carbon)
wipe clean- feel for any groove on the pintle- got groove?get new IAC.

Before re-inserting IAC, reach into the bore and clean the seat-where the pintle rests-

all the pintle does is move in to set on the rest in the throttlebody and out- no "adjustment" to get out of whack is available-the computer tells it how its done.

If you have an 87, and never have done this- your wayyy overdue. Its common pratice to do an IAC and throttlebody clean at the same time- every 3ed oil change in my case. Their carbon producing monsters- you have to clean them out or they get plugged up.