Hey guys hope you can help me out here. I got a 1993 ranger 4x4 with the 4.0. When I go to leave for work in the morning the truck will not start I can hear the fuel pump turn on, any time when it below 40 degrees. When I come home for lunch the truck will start and idle rough until I drive it down the road and it runs fine. When it doesn't start I pull a plug and I have no spark. Any help would be great the thing that has me in a loop is it doesn't start when cold out side.

 

Welcome to the forum

Just a heads up, Ford uses a Waste spark system so you will have No Spark if tested the way you describe.
Waste Spark runs spark plugs in Pairs, so 2 spark plugs are wired in Series and share 1 coil in the coil pack
You can test spark with a timing light connected to any spark plug wire, as long as the spark plug is still connected

But easier to just do 50/50 test
Spray gasoline or Quick Starter(ether) into the engine and crank it
If it starts and dies then you have a fuel issue
If it doesn't start then a spark issue
50/50

1993 4.0l ignition system is independent, it uses a Crank Position(CKP) sensor, located behind crank pulley at about 10:00 position, it reads a "tone wheel" that spins with the crank shaft, tone wheel has one missing "tooth" that denotes #1 piston at Top Dead Center(TDC).
The Crank sensor is connected to the EDIS-6 module, usually located on Radiator support, can be on the Front side behind the grill or on the back side in engine bay
EDIS module times the spark using the Pulses from the Crank sensor
EDIS module is connected to the Coil Pack

So startup spark are these 3 parts, CKP sensor, EDIS Module, Coil Pack, and wiring between them

EDIS Module does send CKP sensor pulses to the engine computer, so it can time fuel injectors, and the Computer does send back spark timing "suggestions" because it has Driver Input, i.e. throttle position.
But for Startup its all EDIS, no computer needed


ALL gasoline engines need to be CHOKED when cold
Choke means to run RICH with higher idle
With fuel injection the computer has to do this, there are no Jets so can't use a Choke Plate
So all engine computers have an ECT(engine coolant temp) sensor, this is a separate sensor used only by the computer, nothing to do with dash board temp gauge(it uses a 12volt SENDER), ECT sensor uses 5volts, so not interchangeable

On cold start computer should run engine at 1,100rpms at least, the colder the temp the higher the RPMs
Then as coolant/engine warms up the RPMs should start to drop, within a minute or two, after 5-8 minutes of running RPMs should be down to 700 or so
If this happens then ECT sensor is OK, if it doesn't then change ECT sensor.
It is on the lower intake just above thermostat housing, it has TWO WIRES, the Sender is next to it and has ONE wire

 

Checked the codes I got 114 and 116 so I replaced the engine coolant temp sensor and same story. I checked the fuel psi at the rail and have 41psi.

 

Post code definitions with the codes since you have already looked them up

114 - IAT sensor out of range, IAT is intake air temp sensor, runs on 5volts from computer, located on upper intake until 1995 when it was moved/combined with MAF sensor
116 - Engine Coolant (ECT) sensor out of range, runs on the same 5volts as IAT sensor..........................

There are two ECT units on the engine, a Sensor and a Sender
ECT sensor is used by the computer only, runs on 5volts
ECT Sender is for dash temp gauge only, runs on 12volts, so not interchangeable

And are codes gone?


Both codes could mean engine is not warming up enough, computer expects at least 150degF after 4 minutes run time, these are the only "temp" sensors the computer has, so getting both at the same time would point to temp issue or computer issue

 

Codes are not gone, its currently 35 degrees here and I read on another thread that if its below 50 it's possible to have these codes out of range.