When I try to start my 95 F250 5.8L E40D auto this winter it doesn't like to stay started, if its below 20 degrees F out it will fire no problem, high idle for maybe a second then die. I have to give it some gas to keep it going and after 5 mins of that it Idles "okay." The problem has seemed to get worse because it was 33 degrees and still did the same thing only instead of dieing the RPMs would drop really low and it would barely idle, sparaticly jumping up and down. I did a tune up when I bought the truck in august of 2018 (except plug wires...) so this is it's first winter with me and it was a southern truck so its never seen this cold of a climate before, maybe its just not used to it?

From my research I think the problems could be the Throttle Position Sensor, the Engine Coolant Temp sensor, the Manifold Air Pressure sensor, or the Mass Air Relay sensor. I think its a sensor because once it stays running the truck runs and shifts really nicely and smoothly, except when in park just idleing after driving it seems like the engine RPMs move around a bit but I don't have a Tach in my truck to see for sure, could just be the clutch fan I am hearing, to my knowledge all of these sensors are original. I don't have an OBD 1 tool so I cant look at what they read.

So far I have taken the throttle body off to inspect and clean it, nothing jumped out at me but the back of it as well as in the intake plenum was sooty and black, the Mass Air Relay has a little physical wiggle to it not sure if that's normal or maybe its a cheap, aftermarket unit.I also tested the alternator and that tested fine, but again it was a southern truck so maybe its not used to it being this cold.

Any help is really appreciated thank you. BTW the truck has 186K on it engine and trans original.

 

Looks like your stilling having the same issue as your first post on the problem: https://www.ford-trucks.com/forums/1...-troubles.html

 

Plug wires are an essential item for a proper tune up. You may have plug wires with 186K on them and an expert like rla recommends new plug wires and you don't do it is not going to get you much help. I would tell you how to run codes without a reader but I will wait until you put new plug wires on your truck as codes now may steer us in the wrong direction..I use Motorcraft wires. Sandy

 

I am not claiming to be an expert, but do profess covering the basics. Once those are done you know what you are working with. Too many times issues and root causes have come down to a simple worn out item that was thought to "be good, because it looked okay."