My truck ran yesterday, but not today

The code is for map sensor high voltage so the computer thinks the engine is under a greater load then it is thats why the engine is loading up with fuel. Also did you inspect all the wires to the map sensor to make sure the wires arent shorted together?Dont worry about the flag for review they will figure out you hit it by mistake.

So your getting voltage to the wire that goes back to the ecm that shows it as a ground inside the ecm?If thats the case then there is your problem if you run a new wire it has to go from the ecm ground like shown in the diagram and then back to the sensor. Not just to chassis ground or you can just try to see where there is a partial connection between the 5 volt refrence wire and the ground coming from the ecm. So iam correct on what is going on with which wire you found with voltage?

Alright the grey 5 volt refrence to the map splits off and also feeds the tps and the linear egr valve 5 volt refrences. The ground to the map sensor only splits off to the coolant temp sensor the purple wire to it. See if the purple wire to the coolant temp sensor also has battery voltage to it.I also posted a couple of wire diagrams so you can see how the wires split off and where they go.

Why would you have power to the ground side of the map sensor are you checking these wires with the sensors unplugged I hope?The purple wire comes straight from the ecm it shows that wire is grounded inside the ecm. Then it splits off to the purple wire to the coolant temp sensor. The grey wire to the map sensor shows it as a 5 volt refrence so that should have power then it splits off to the tps and egr. The power to the wires that are suppose to be ground would explain the problem you had with the map sensor and the coolant temp sensor which you replaced.

The coolant temp sensor has a ground feed thru the purple wire and the yellow wire is the sensor signal to the ecm. Based on temperture the coolant temp sensor changes resistance so that changes the ground value from the purple ground wire so that way the ecm knows what temp the coolant is.I hope that makes it clear for you how it works.

Were getting a code for high map sensor voltage I would start there with that code.

Alright a couple of things here lets get back to your map sensor what ever happended to that?Also with all the sensors plugged in but the map sensor do you have the 5 volt refrence and the ground wire being ground like you should?If not we need to start there. As far as your fuel pressure regulator what is the vacuum reading to it at idle?

The ground wire to the map sensor shouldnt have voltage to it period sounds like the power is shorted into the coolant temp sensor signal wire and is comint thru the coolant temp sensor. In the wire diagram it doesnt show a 5 volt refrence coming from the ecm to the coolant temp sensor. It shows a refrence wire the way the coolant temp sensor works is one side of the sensor has ground from the ecm. That goes thru the coolant temp sensor and as the sensor changes temperture from coolant it changes resistances value. So the resistance change is inputed in thru the other wire to the coolant temp sensor the signal wire. That goes back to the ecm so it can use that change to tell what temp the coolant is. So there shouldnt be voltage there. Because that would throw off the coolant temp sensor reading and the map readings. Like I said before that would explain the map and coolant temp sensor issues you had with it.

Alright I must have been half asleep this morning when I said there isnt voltage to the coolant temp sensor the one wire is a shared ground and the other is a 5 volt refrence from the ecm. Thats what I get for just waking up and answering questiins while iam in bed. Do you you have a scan tool that can read live engine data on that car?

Alright get me one of it idling and with the key in the run position and engine off.