Cant loc the idle air control vavlve located on a 1988 crown vic

Most likely the Idle Air Control Motor, but you could have other issues suck as a leaking fuel pressure regulator, bad EGR valve, or massive vacuum leak.

Dependent on what year you have. If it has an idle speed motor that could be cleaned as well as the throttle body. Idle speed motor may need to be replaced sometimes a good cleaning hooks them right up.

This is caused by the IAC valve. Over time the valve becomes gummy and inoperative. Get it replaced and the problem is solved. IAC stands for idle air control, hence the stalling concern.

perhaps you have a sticking IAC valve. Idle Air Control valve. pretty common concern.

if it was called an idle air control solenoid, then no it isn't hard to change. its on the throttle body area

Inside the fuel tank

i am trying to install an aftermarket temperature guage with capillary tube into my 1988 crown victoria ltd 5.0 efi. where does the capillary tube mount?

change the egr vavle !!!!!!!!

When you turn the key on does the check engine light come on? If not it may be burned out. It sounds like a MAP sensor or an O2 sensor is bad. I would suggest taking it to autozone as they do free diagnostic and seeing if a code comes up. If it is a sensor it should, if not it may be the idle sensor not reading right in the ECU. More than likely it is one of the sensors though.

change the idle air control valve and this will stop.