New owner. I got lucky (I think) for $1200, but I have some problems. After my first 300 miles as I was pulling in, all of a sudden engine dies. Spins Freely. Checked one of the wires to a plug, no spark. No experience with this type of ignition system (I am from an earlier time). I am inclined to test the position sensor. I believe I need an AC multi meter across both leads and should look for .5 - 1 volts. ODB II scanner gives link error. No engine warning lights come on. All suggestions are welcome.

 

Welcome to the forum

When you turn on the key does the CEL(check engine light) come on, it should?

If not check fuse #13 in engine fuse box, 30amp, this powers up computer and most engine systems

OBD reader can't connect if computer is not on

The Coil pack will have 4 wires, one Red wire, test if that wire has 12v with key on
If not then fuse #19, 25amp, in cab fuse box is blown, rare but can happen

This is a Waste spark system so can only be tested with all spark plugs hooked up, can't test one wire for spark
best test is 50/50 test
Spray fuel into the intake and crank engine
If it starts and dies you have spark but no fuel
If it doesn't start then no spark
50/50 spark or fuel

From the old days, dump fuel into the carb and crank, lol

 

Many thanks #13 50A is good so is #19 and Red wire is hot with key on


Fuel in inlet makes no difference. Depressed the schrader valve and no fuel pressure.


Looks like I got both of the 50s spark and fuel


Where do I go from here?

 

Blown 30A PCM fuse #2. Off to buy some. What would cause it to blow? Why shouldn't the next one blow?

 

The event occurred at the end of a long trip when I was preparing to pull into by driveway. I put the Ranger in reverse (a short inside the steering column?) and either at that moment or when I stepped on the gas the engine stopped


PCM Fuse testing

Side 1 Hot

Side 2
With Key Off - Open Circuit
With Key On - Closed Circuit
With Key On and PCM Relay removed Open Circuit
The above 3 tests were conducted with a test light connected to the positive side of the battery and the probe in Side 2 of the fuse receptacle


PCM Relay
With PCM Fuse Removed
Key off not activated
Key on Activated

 

Odd, I have fuse #13(30amp) for PCM relay power

#2 is 50amp, powers all the full time stuff, PCM memory, radio memory, brake light, cigar lighter, GEM(timers), and a few other things

PCM relay fuse sends power out thru the relay, I know duh, and it powers all the engine devices, PCM, injectors, O2 sensor heaters, EVAP solenoid, EGR solenoid, Automatic trans solenoids, MAF sensor heater, IAC Valve, Cam sensor.

But not crank sensor, it generates its own AC Voltage
Failed crank sensor can kill the engine, no spark and no fuel, only sensor that can stop an engine, but rarely fail on Fords

 

PCM relay powers Automatic trans solenoids? The engine quit when I put it in reverse. I need a circuit diagram. Is there a location where I can disconnect the Automatic trans solenoids to test?
Many thanks

 

Yes, at the transmission drivers side just in front of the shift linkage is the 16 pin connector, you would pull the connector to test harness and then transmission solenoids

Diagram here: http://www.diakom.ru/CAR/Ford/1997/R...RAMS/15632.pdf

And this does show fuse #2 as the power source, my other 1997 diagrams show #13

Picture in this thread, post #15, shows cionnector numbering: https://www.ranger-forums.com/2-3l-2...engage-156898/

 

That was excellent information, and a very helpful diagram. The second link did not work.
I disconnected both connectors at the transmission and wired in a circuit breaker to avoid costly fuses.
The circuit breaker still tripped
Looking at the circuit diagram (on the learning curve here) and following the Red wire down from the PCM power relay (top right of diagram) I am looking for opportunities to disconnect for testing. Just below the relay there are 3 wires going off to Engine Controls (they are dashed wires) Can I unplug them? where are they on the chassis? Going Further down the next connection is to the block on the bottom of the page. That must be the transmission plug that I disconnected. That means my short has to be along the red wire or off the Engine Controls. Do you agree?:

And thank you so much for helping out. I am way ahead of where I was a few days ago

Richard

 

Yes, if transmissions 16 pin connector is unplugged and wire is still shorted, then its in the engine bay

Unplug these:
IAC Valve
EVAP solenoid
EGR solenoid
Cam sensor
MAF sensor

PCM connector has two of these Red wires

If you put an OHM meter on any one of these red wires and a Ground, key off PCM relay pulled out, you should see low OHMS, a short to ground
Then move wiring harness around to see if the OHMS change, so short inside the harness

 

I did not succeed in disconnecting the cam sensor (yet), but with the rest of your instructions followed I did not detect a short. Your link to the pinout was not compete and I can not find an appropriate one on line, but I attach a picture of my setup with a safety pin piercing one of two red wires. I did notice that I had not closed my power steering cap properly and my EVAP solenoid connector was soaked.



From here I will wiggle wires, connect one sensor/solenoid at a time. Incidentally my transmission connector is still dangling, I will connect that first.

 

When I connected the EVAP canister solenoid, I got low resistance. I disconnected the EVAP and reconnected everything else with no short detected. I washed the Power Steering fluid away from the EVAP connector, and connected it and everything else, and my Ranger is running. Either Power Steering fluid can blow a 30 amp fuse, or I moved some wires. The harness is very intact on this 49K car, but still I worry.

I wish to thank you very much, I was without economical options. You made my day.

Now I can spend my time with my other pursuits


Richard

 

Good work, yes any fluid can short a 2 wire connector

Thanks for the update and the FIX info

Cool video