Hi everyone, trying this thread again as the last one seemed to have a bad link and not want to open.
anyways I have a 1994 ford ranger 4.0l manual that recently developed a crank no start. It sounds like it wants to fire and then immediately dies.
-fuel psi at rail is approx 30-35 psi with key on.
-battery voltage 12.8ish
-gets spark / checked 2 cylinders with inline spark tester light...
- noid light kit should arrive today , so will check that next...
-checked fuses and replaced relays in engine compartment.
...list of things I've replaced this week
fuel pump, pcm, ignition control module, crank position sensor, coil pack. I feel like I've changed all the common components that fail... if you guys have suggestions I sure would appreciate it....
( also checked the inertia switch it's ok...)

 

Welcome to the forum

First test on any "Crank but no start" is the 50/50 test

Spray fuel, ether or gasoline, into the intake and try to start the engine
If it starts and then dies your problem is Fuel related
If it doesn't start then its Spark related
50/50

Find out which and go from there, or let us know

 

Ok, did the 50/50 test, it sputters maybe just a little more with ether. Just to reiterate I did check for spark ( good) and also hooked up noid light to injector harness. An interesting thing was it would light up one or two pulses whilst cranking and then no more ( even though I continued to crank for a couple of seconds.) Also in the chilton manual; if there are no reference pulses from the ignition system, the fuel pump will shut off after 2 or 3 seconds.

 

Ford shuts off fuel pump after 2 seconds regardless, so each time key is turned on fuel pump runs for 2 seconds and 2 seconds only
So you can build up fuel pressure by turning key on and off a few times
After engine RPM's reach 400(engine started), fuel pump comes on again full time

So 50/50 test was a no start, then spark is the issue
You can't "test spark" in any practical way without a timing light, and even then its a marginal test, because you can't determine spark heat
If you tested it and think you have spark then why didn't engine start when you added fuel manually, it should fire right up and run well until it runs out of the gas you added
50/50 tests spark Heat AND spark timing at the same time

Add more gas or ether and try again just to confirm no spark.

1994 4.0l uses an EDIS-6 module for spark, they rarely fail, it is located on drivers side FRONT of rad support, have to look up under the bumper to see it
The spark system has 3 components, Crank sensor/tone wheel, EDIS-6 module, Coil pack

It is an autonomous system, doesn't need engine computer for start up, it does send engine computer crank sensor timing so computer can time injectors, the PIP signal, if your NOID light was not pulsing while cranking then that would also point to EDIS-6 or crank sensor

The Crank sensor is easy to test, and MUST BE TESTED, not replaced, need a volt meter set for AC volts, yes AC not DC volts
Hook it up to crank sensor and crank engine over, at 150-200rpms crank sensor should show .5-1.0volt AC, steady if its jumping around then sensor or tone wheel is damaged
This is a variable reluctance sensor, super reliable, so have a look at tone wheel, should have 35 "teeth" and one missing tooth, should be clear of mud and debris


Its possible but unlikely compression is low, the timing chain on the 4.0l OHV never fails, but there is always a first time, and low compression presents as no/weak spark on 50/50 test

 

Thanks for the reply Ron! I was out messing with it before it got too dark out... I did the 50/50 test by myself, tomorrow my kid will be over and I can have her crank while I give a shot of starter fluid. I did set it up where my iPad could video while I cranked and did see spark fwiw. Also this evening I was cleaning up grounds I found the positive running down to the starter feels really loose/ loose nut on the starter end. Tomorrow morning I'll jack her up and crawl underneath to tighten everything up, hopefully that does some good! Btw I didn't mention the tachometer is working, but I don't think it is cranking to 400 rpms.... and as far as dash lights, nothing really comes on like check engine, seat belt, brake etc...it seems like all that used to come on when I'd turn the key over...

 

Full crank speed with a brand new battery is only 200rpm

Engine started is 400 and above, which is when fuel pump comes on, no need for it to be on before that
The 2 second thing is for safety, if there should be an accident and a fuel line breaks the engine would stall and if the 400rpm rule wasn't there the fuel pump would just keep pumping away, maybe feeding a fire, or starting one.
Yes, inertia switch is also there for that reason, but why not have two safety switches for fuel pump

Pull off the big air tube to the intake, open throttle and spray ether in, crank engine, don't need to put the tube back on, MAF sensor is not used for startup on a 1994 4.0l engine
Should fire right up and run for a second or two if spark and compression are good