My 88 dodge aries is throttle body fuel injected and when the temp falls below 30 outside, it will crank but not start. I sprayed starting fluid and it ran on that then died. it starts and runs when outside temp is above 30. I checked ignition and mechanical timing and both were perfect. it also has good spark. it seems to flood when it is cold.

lots of guesses. sure.. common here.
first would be a real tuneup , using the 60,000 mile list. for sure.
filters and spark parts. (my guess is you did)
1994 is a great year, all 93+ jeeps are good from 93 to now.
I presume this is USA car, and you scan it and there are no
DTC errors.????
seems its flooding ,
if 5% throttle makes it start, that is lack of air or flooding
if wont start and the super secret WOT crankings clear flood , then was flooded, Wide open throttle cranking , cuts all fuel (the secret)
so is , IAC/ISC stuck closed, chean it yet.
or injector leaks (pass the injector leak down test ,does it?0

got 500k miles o jeeps from 88 to 99+
and the ISC stick on them all.

the ISC is the electric, ldle speed control valve.
if it sticks closed, you cant get full air supply to start.
had to clean mine every 10 to 20k, miles.
until i found the magic, spray that cured that.
"klondike gun lube spray": looks like teflon after it dries.

that run rough started is called misfire.
and is flooding, (if injector are not leaking) its air supply wrong.
one more thing,
the ECT must read 30F when parked overnight, and was 30f.
see? a cold engine will be near ambient air, first thing, in the morning.

running old fueL:?
running summer fuel from last August?
the ECT sensor causes injections to match true temps.
make sure it reads right for all bets off.

clean ISC first. not shot gun parts
for that cash you could have got a nice scan tool.
like this.

http://www.walmart.com/ip/Equus-3140-Innova-Diagnostic-Code-Scanner/14644660

the prefect tool for 93-95 jeeps. does OBD1 on JEEPS !!!!

yes it should suck the gas in not blow it out.

sounds like you have a fuel pump problem, fuel pumps will usually get hot and then shut off allowing it to sit 30 mins lets the pump cool down allowing it to start pumping, the way you can test it is get a can of starting fluid the next time it quits raise your hood and spray some fluid down into the throttle body and if it starts and then dies it is most likely your fuel pump, hope this helps.

Did you check the fuel pressure before you replaced the pump ?
Can you spray carb cleaner or starting fluid into the throttle body and make the engine want to start ?
If it is throttle body injected, can you see the fuel spray when you crank it hot ?

starting fluid is a thing of the past. dont use it. this car doesnt have a carb, its a throttle body/ electronic fuel injection system. you most likely have a fuel pump or fuel pressure regulator issue. test the fuel pressure, should be anywheres from 35-50 psi

Sometimes you can straighten the little rod to have it close better using a pliers

Sounds like the fuel pump is bad

Vehicle has a carburetor and you might want to make sure the choke is properly adjusted and not sticking.

remove the air filter housing from the throttle body, or if its mult-ported injection, remove the large air duct. Do this the night before. The next day, before cranking and having a spray can of carb. cleaner, spray a couple of shots of carb cleaner either into the large air duct, spray towards the engine, or if its single body injection, spray directly on to the throttle body.

Crank engine immediately, preferrably have some one else sitting in the car to start it after you spray.

If the car even tries to start, replace cold start relay.

its the map sensor