I have a 92 f250 with a 351w 5.8L auto. It has 175,000 miles on it. Two winters ago the issue arose. Start it in the morning and it would run like it was not fireing on all cylinders, it would clear up in a short time and run fine as long as it was warm. This winter the same but its gotten worse. It will start and miss but will not clear up even after it warms up as long as its cold outside. If i hold it at about 2000 rpm's it seams to be firing on all cylinders as soon as i leave off the gas it shuts off. Then it will only fire up if i hold it to the floor. Now if its a warmer day it fires up idles fine and drives fine. It started even in late fall when the evenings were cool. I have replaced the coil, distributor, model, fuel filter (6 months before winter), cap, rotor, ingition key switch, plugs, wires also 6 months ago, Air filter was cleaned. i don't drive this truck much, its mostly to haul fire wood and haul my derby cars around. I mostly only go short distances. One thing that comes to mind is sometimes i run a tank down to about 1/4 tank and will switch to the other tank, once that tank is down i switch back to the other tank and it will have more gas in it than when i switched off of it. I don't have a fuel pressure gague yet, but i have fuel pressure in the rail just don't exactly how much. I'm kinda exghusted with this truck, but i still like it and don't want to get rid of it. Any ideas would be greatly appreated Robert.
I haft to agree with the above post sounds like it is flooding the engine out. When holding it at WOT your turning the injectors off and allowing it to clear out. And when holding the RPMs up its getting enough air to keep itself running. So it leaves you with a bad ECT. The warmer weather allows the ECU to see a warmer temp. on ECT and thus doesnt flood itself out. Could be the IAT also. The problem of back fill the other tank is a bad return valve in the pump of which ever tank is back filling. I have the same problem with mine. Just use that tank first then the other and return to the first if I dont feel like filling up yet. Or you can replace the pump and should fix that issue.
I forgot that the last thing i changed was the coolant temp sensor. It was right by the upper rad hose on intake. Do i have to unhook the battery or something to reset the computer. I never did that until right now because someone borrowed by battery.
The one i changed had two wires and had a nice convenent quick disconnect. Was this the right one? Put a battery back in it and its the same thing. you can smell the gas its definity flooding itself. Should i look into replacing the ACT? Were abouts is it located?