Intermittent Starting
 

I have a 1994 Ranger 4.0L with 240,000 miles. Have recently begun having a problem with it failing to start (cranks strong, just won't start):
If driven for 30 minutes or more and then turned off for 30 minutes-1 hr it will not restart until engine has cooled for at least 2-3 hrs (will usually restart if cranked immediately after shutoff).
Have replaced:
fuel pump & fuel pump relay, eec relay, plugs/wires, coolant temp sensor, ignition control module
Cleaned:
maf sensor, battery posts
Fuel pressure tested out as being good.
A friend had an OBDI system to pull codes. Showed a code for "engine oil level sensor out of range".
Question is: Can this sensor being bad cause an intermittent start situation since none of the "obvious" causes fixed the problem?

Welcome to the forum

No on oil level sensor, and what is that code number, exactly, you may have wrong definition?
As far as I know there are no "oil" codes

You need to do a 50/50 test when there is a No Start
Get a can of quick start, ether in a spray can

Do whatever you need to do to get a No Start, and make sure it doesn't start
You need to spray ether into the intake, or gasoline
Easiest way is to pull off PCV hose from upper intake and spray ether into that port, put hose back on intake, you don't need much, just a quick squirt

Now try to start engine
If it starts and then dies you have a fuel delivery problem
If it doesn't start then you have a spark problem
50/50, instant results

This will put you on the right track instead of guessing

I tested the fuel pressure on the last "no start" and it showed good pressure so I am getting fuel.
Ran OBD1 on both the electrical and engine itself. Electrical did not show any problems. Engine test just said "engine oil temp sensor out of range" did not have a number with it. Everything else passed without a problem.
Will definitely try your suggestion! Thank you!

Just because you have fuel pressure, doesn't mean your injectors are working, so could still be a fuel related problem.

On the next no start you still need to do RonD's 50/50 test.

Update:
Was able to try starter fluid.
Engine "acted up" as usual (crank but no start). Sprayed starter fluid into intake and it immediately started and kept running. Turned engine off and tried to start again w/o starter fluid--- started immediately. Continued turning engine off and on 5-6 times. Started up immediately every time.
Is there a component (other than the computer) that tells the fuel injectors when to fire?
I am prepared to have to replace computer but want to eliminate any other possible factors.

On 1994 4.0l Ranger you have the EDIS-6 module spark system

It has 3 parts
Crank sensor
Coil pack
EDIS-6 module

Whole system seen here: http://i17.photobucket.com/albums/b8...DIS-6Large.jpg

Crank sensor starts to generate its own AC voltage when crank starts to turn
It sends this to EDIS-6 module, this AC Voltage has a timing pulse
The EDIS-6 starts firing coil pack using the timing pulse fron crank sensor

EDIS-6 also sends that timing pulse to the Computer so it "knows" driver wants to start engine and to time the injectors, signal is called the PIP

There is no connection between starter motor system and computer or spark system, so the ONLY WAY EDIS-6 or computer knows to start spark and fuel is by the crank sensors pulse
This is actually the ONLY sensor that can cause a no start if it fails, but it never fails, lol, and in this case its not failing because you had Spark or it would not have started with 50/50 test

It is possible the EDIS-6 is not sending the timing pulse(PIP) to computer or that wire is bad, but there is also a 2nd wire, the IDM, its the "tach" wire which also goes to computer, so there would be a CEL and code if either of these wires/signals were bad


Are you SURE there is fuel pressure when No start happens, as soon as RPMs hit 400 fuel pump gets full time power, so if it started with 50/50 and kept running it could have had no fuel pressure for the no start.

Its far more likely to get an intermittent fuel pump than PIP or IDM signal, it wouldn't keep running it that was the case

Positive I have good pressure. Checked on a previous “no start”. Ran code check also. No codes thrown. The only time the CEL has come on was right after it started with starter fluid the first time. Stayed out on all other restarts after that.

See if there was a code set in memory

That might tell you what was missing

The EDIS-6 module is on front side of Rad support drivers side, have to look up under the bumper to see it, maybe connector got some water intrusion???

And check the crank sensors tone wheel, the thing that looks like a gear, long shot but if it has mud caked on it, it can cause sensor reading issues

Grasping at straws here, lol.

SOLVED!!!
 

Replaced the Crankshaft Position sensor.
All seems to be well now!
Have had cooler weather this week so main test will be when warms up again.
I did drive it non-stop 100 round trip miles 2 different days and let sit as usual each time.
Restarted with no problems!

Thanks for the update

Never read about crank sensor acting like that, good to know, they do fail but never work again when they do, so it was an odd one