well after getting the second new starter tonight the truck cranks fine, well after a short drive as i was pulling into the driveway i noticed that the RPMS went extremely low as in prolly 300ish so i went back out and the truck runs great goes threw the gears and has no lost power, but when you slow down the RPM's drop and the engine will die out then come back, in drive the idle is prolly 500ish unless you slow down its goes waaayyyy down but in park itll run fine and stay in the 7-800 range which was normal for the truck, it only seems like after you let off the gas the rpms drop

any ideas?

 

Take a look under the truck if the transmission has a speed sensor that may have the connector pulled out not seated well.
At decelleration, the PCM should keep control of the IAC so the motor does not do that.
Next, I would clean the IAC to be sure it's not sticking and it's connector is seated.
IAC control is the only way the PCM has to control the idle, at all times.
Good luck.

 

Where might this plug be if it has one? 97 F-150 4.6 4x4 automatic

and cleaning the IAC is it fine to clean it with Carb/fuel injector cleaner or something else?

 

after letting it warm up this morning i messed with it a little more itll do the same in park or neutral if you rev it up it dips down below 500, so this leads me to believe it has nothing to do with the tranny, so i pulled the IAC this morning and the inside of it was black as the ace of spades so i hit it with a little carb and choke cleaner and some the stuff came off so ima pick up a new can and clean it up good this morning (i barely had any left when i started it didnt spray for 30 seconds..)

i also pulled the air filter out and its nastey black i know it says dont replace it or what ever but im pretty sure this one will not clean up so im hoping after getting all of that cleaned and fixed maybe itll run better...

 

....I metioned the transmission because at that point you or I did not know the full extent of the issue.
....While driving, when you let off the throttle, the speed sensor is part of the feedback data that keeps the engine from stalling by not letting the IAC fully close when the throttle plate goes fully closed, preventing engine stall during decelleration.
....If this action were not designed into the program, you would be restarting the motor very often at a stop sign or traffic light.
....The speed sensing is the only way the PCM has to know what that driving condition/intention is besides the TPS and RPM.
Good luck.

 

I had my buddy scan it today (he runns a repair shop has all the goody's lol) and said that it showed it was still relearning its self after having the battery disconnected for 2 or 3 hours the other day i forget what code # he said it was

 

Your going over board on some of this.
It only takes a minute or so to reboot the computer after power down.
Only thing that is happening is the table memories drain off leaving the base firm program that you can't touch no matter what is done.

Every time a clear is done or a power down, the program goes back to re-diagnos all the functions all over again.
You will see a code 1000 with a good scanner and the PIDS that were not completed will show.
The fuel system takes the longest.
Spend your time finding why the IAC is not working instead of rebooting.
It does not help anything to reboot until you find the problem.
I'm trying to tell you how things work but you not wanting to listen much.
Good luck.

 

I took the IAC off and cleaned it got it shinning nice I just had him scan it to see an it was the 1000 the more I drive it around the better its got

 

Assuming there is no other issue, the IAC program operation has to relearn cold starts, hot restarts and load control with A/C and lighting loads and battery rechargeing loads.
This should be handled for the min amount of relearn time by rebooting, then cold start to full warmup with lights and heating fan on so the tables are rebuilt for max loading.
Then drive about 5 miles and do several hot restarts so hot restart sequence is learned and includes the battery recharges in the sequence.
After all this, the full range of starting conditions should be perfect everytime anytime.
Good luck..