1988 F250 EFI Custom
 

Hello,

I have a 1988 F250 EFI custom (I think its a 351)

Its a beast for sure. When it has been sitting for a day or more and I try to start it up it will start up and idle just fine but if I put it in gear, Drive or reverse it dies unless I let it run for about 5 to 10 minutes.


What I've tried:
New plugs & wires
New rotor & cap
New Fuel filter
Oil change & filter

This improved its up hill power by a lot... I was only getting up a hill at 45 mph before and now I can take the same hill at 60ish

Any other ideas would be helpful...

Brian

I don't know if this is the cause of the problem, but from what you describe it sounds like the coolant temp sensor is not providing the correct info to the ECA (computer) and therefore sufficient fuel is not available to the engine when below a certain temp.
It doesn't have to be non working , but if it is telling the computer the engine is warmed up when it is not , ,,,,,,,,,,,,,well worth checking .

that may be a good place to start since the coolant temp gauge on the dashboard does not work....

ok where did the engineers hide it?

It should be located just behind the thermostat housing. If I remember correctly it screws into the front of the lower intake manifold..
It should have 2 wires going to it. One wire brings the 5 volt reference voltage from the computer to it and the other wire goes back to the computer as a signal return (ground)..

I stopped at O'Reillys and they asked me which one I wanted... there are two of them.

Since we can't tell from here, just kidding, I would suggest taking both with the understanding you could return the wrong one, Would that work for you ?

Is there a seperate sensor that goes to the dash gauge? where is that located?

Brian