good morning! time to turn to the pro'sand fingers crossed that you can help. here is the problem: 1999 dodge ram van 3.9L, when it sits overnite (temps 20's to 30's) van will not start in the morning. it will turn over and catch, will idle high for a second but when returning to normal idle speed, will shut down. will do this over and over. it will eventually start after some time, I'm talking at least a half hour of intermittent attempts. when it does eventually start, it will be fine all day long until the next morning. here is what i did so far:
changed the plugs, plug wires, distributor and cap, air cleaner, engine coolant temp. sensor. there is spark and fuel at the rail. I'm at a dead end and this is my last stop before the shop. Hoping you can help. thank you now and in advance.

 

will it continue to run if you press on the accelerator and dont let it return to idle?
would probably have the battery checked for a starting point have a load test done on it to see if its ok.

 

thanx for ur response bejay. no, i can rev it for a few seconds but it will still cut out. I'm waiting for my brother, he's going to bring some ether over. i'm gonna spray that in and see what happens

 

well, after banging my head off the wall again today someone suggested to call the local dodge dealer... they had the answer before I finished trying to explain the problem.
AIS motor... never heard of it but put it in and I guess i'll know in the morning if that was the correct answer. I'll keep you posted.

 

Automatic Idle Speed motor was the wrong answer, i'm going to try the battery.

 

Lets think abit here
If it were an old carb vehicle I would think the choke is sticking
It runs good when warmed to operating temp.
It starts good on start but dies short after.
I know that Chevs had 2 temp sensor
Lets think that it had 2 temp sensors
One for start (cold enrichment) and one for warming up
I will try to find a wire diagram and see if I am close or barking up the wrong tree

 

Check the fuel pressure, some electric pumps are known th have a cold soak problem. Could also be the pressure regulator sticking open(low pressure) while it is cold. The regulator works off of vacuum, when the engine first starts vacuum is high, which pulls the regulator open and reduces the fuel pressure, if it sticks the pressure would stay low and the engine could cut off.

 

I'd be looking at IAT (intake air temperature) sensor. The V-8's have a throttle body temperature sensor usually on side of throttle body (obviously) that does basically same, but on the 3.9L, the IAT sensor should be threaded into the intake manifold. Should be under air cleaner (you'll have to remove it) behind alternator, near top of intake. The IAT sends info to ECM regarding incoming air temperature & ECM uses this info to adjust injector flow (pulse width etc.) Approx. $35