93 roadmaster - starting needs prime after sitting - somtimes

after sitting for a few hours it sometimes needs a squirt of gas in the throttle body to start, then runs and starts fine. Maybe a fuel pump issue but hoping for something simpler.

Sounds like a weak fuel pressure regulator. Might be time to give the TBI unit a refresh.

will have a look (when I figure out where it is )  [found it]
It would also occasionally stall out at a red light with AC on, does that support that diagnosis?

Possibly a fuel pump, or bad connection to the pump somewhere. When the engine starts, it may cause the connection to make contact. It could also be the ground at the thermostat housing. I would look at the ground at the thermostat, fuel pump relay, and the pump itself, in that order. The electric antenna relay is the same as the fuel pump relay, and located next to it. Probably not the regulator, or starting it with some fuel in the TBI would not make it continue to run.

One more possibility is the IAC. If it is closed, the car will not idle, and it will affect the engine at idle with the AC on.

With the engine cold, remove the bolts to the thermostat housing, and clean the threads in the manifold, and on the bolts. Clean the top of the ground stud, and the lugs. Reassemble. You do not have to remove the thermostat housing from the manifold, although it may come off. If it comes off, replace the gasket.

Did you check for codes in the computer? If not, check them, and get back to me.

What does the coolant temp sensor read compared to ambient?

The coolant temp sensor on the TBI does not keep the engine from running.

If the sensor is reading 40F high, won't it lean things out on startup thinking the engine is warmer than it actually is?

Similar but opposite effect, if it's unplugged it thinks it's -40F it riches the Air/Fuel ratio to something like 3:1 on startup.

If the sensor is out of range it will cause a code, and the computer will go to a preset "base" reading, and the computer will stay in open loop.

I was only getting 1 2 on the codes, but today I went back and waited longer and finally a 23 showed up - mat sensor. Another site suggested it might be stuck on high.
If that is the bolt thing that screws into the top of the engine, I remember replacing it about a year ago.

23 is IAT. Incoming Air Temperature sensor. It is located on the right side in the back of the air cleaner box.

Got it thanks, was not sure tbi counted as fi. Is that the right side looking in from the front of the car? There is a lead coming out on the passenger side attached to a small sensor.

Passenger's side.