the idle is real high when its in park about 2 grand in drive it drops
to about 1 grand i have a new throtle position sensor that i got with
the truck but i dont know where it goes i think that it will solve the
problem the check engine light comes on after it runs for a bit i m
looking for a code reader but all i can find is readers for 96 or
newer the truck motor and tranny have never been rebuilt and have
264000 miles on them it runs real strong just idles real high im also
looking for a new tranny for it i need the e40d tranny 2x4 if you know
of any good deals/ please help asap thanks

The TPS may need replacing but, I do not think it is your
problem. Very high idle as you describe is usually a big
time vacuum leak. That vintage sometimes had a problem with
the upper intake gasket assuming that noone has screwed
around with the idle stop or something like that. If you
have have mechanical skills equivilant your ability to find
the TPS, this will be a job to be farmed out. If you E4OD
trans needs an overhaul or replacement, your '92 F150 is
probably not worth repairing. With a bad trans and a
spastic engine, you have a $300 truck. After you spend a
couple grand to get it operational, you will have a $1500
truck. You can search google for Ford EEC IV codes to find
instructions and pictures of how to get the fault codes.
Your next problem wil be finding the EEC IV diagnostic
connector over the left fender in the engine compartment.

Good luck

Lugnut

Check for vacuum leaks. Not just in hoses and fitting. Devices that
use vacuum can leak too. I recommend using a MityVac to check for
leaks.

You might want to pass this 411 along to the OP. Mine is
doing just fine.

Lugnut

whats a mityvac and where would i get one ? also i held my hands over
the intake so that it couldnt get any air and all it did was drop the
rpm to about 1grand it should of stalled out right i know it couldnt
get any air cause it sucked my hands in tight where else could it be
getting air from?please help

The MightyVac is a hand operated vacuum pump kit for testing
components. If I were you, I would start with a can of carb
cleaner or WD40 to spray around the suspected leak points
while the engine is running. When the engines changes while
you are spraying, you will have found a leak. Some folks
will tell you to use starting fluid (ether). Do not do this
as it can be very destructive of the engine if you hit a
large leak and it is highly combustible or, even explosive.

Lugnut

http://www.mityvac.com

Unlike the WD40 method, it allows you to test vacuum components, and
doesn't put crap all over your engine that you will have to clean
off. They are readily available at auto parts atores. You can also
use it to bleed your brakes, however if you are going to do that I
only recommend that you use it to drain your brake fluid reservior
then refill with new before bleeding the regular way (speeds up whole
process greatly).