2001 with 110K miles, 70K by me. Bought as rebuilt title after substantial front end damage, sloppily repaired. Engine has had no trouble in 70K miles other than some rubber parts splitting. It has now developed some starting problems that occurred over about a six week period.

Problem #1: About 100 starts ago, cranked endlessly with no sign of catching with a could of cycles with key on. Turned key off then it started and ran normally (engine reliably starts after about a 400 millisecond crank). No more problems, than about 25 starts later:
Problem #2: When starting, initially fired normally then quit after about a second. No sputtering, just quit and gauges snapped down to their off positions. Did this maybe 10 times in a row before I got out and jiggled or disconnected and reconnected connections on the engine. Got back in and it started and ran normally for another 25 starts or so, then:
Problem #1 repeated just like the first time, cranking and cranking but no start until I had turned key off and on. Another 25 starts or so, then:
Problem #2 repeated, just like the previous time. About 10 starting attempts when it fired normally but quit within 1 second. I let it sit for an hour or two and it started and ran normally for the last week and is starting OK now.

Problem #1 only occurred with a cold engine (outside temp forty-ish).
Problem #2 only occurred when fully warmed up after driving 15 minutes or so.

I have taken no action other than checking for fault codes (none found), replacing the battery (5+ years old and very weak because of a couple of complete discharges over the years) and disconnecting and reconnecting those connections normally held together by a bolt (ECU and one other, I think). I have a ScanGaugeII so I can dig deeper into sensors and actuators if I knew what to look for.

Any ideas? The repair shops around here are expensive and troubleshooting an intermittent problem is likely to cost a fortune and I'm concerned I might pay a big bill and still have the problem(s). It sure seems that these two problems are related, but I can't think how.

 

Welcome to the forum

If it was a sensor issue you would have codes

So its a problem with a system not covered by sensors
Which is fuel pump or fuel filter(there is no fuel pressure sensor)
Electrical power, there is no "voltage sensor"

Your description could be an issue with Ignition switch, under steering column, i.e. wiggling key

Carry some Quick Start(ether), do the 50/50 test at the next Crank but no start
Spray ether into the intake, and try to start engine
If it starts and then soon dies, Spark is OK but no fuel is getting into engine
If it just cranks, no start then spark is the problem

Fuel pumps are electric motors, so are HARD to start but stay running once started
So can be intermittant
Fuel filter is a long shot but not expensive to change and should be changed every 5 years or so

When cranking engine over WATCH the CEL(check engine light), it should go OFF when engine is turning over, that means computer is getting a timing pulse from the crank sensor, without that pulse there will be no spark or fuel injectors
But that should set a code so long shot

2001 Ranger has PATS, this will disable fuel injectors if proper Key is not used for starting, but starter motor should also not work if PATS was activated
There would also be a Rapid Flashing THEFT light on the dash if PATS was the problem

 

The ignition lock key assembly was my first suspect -- I have had failures in other vehicles. I tried jiggling and twisting it while running and did not have any misfiring or changes in lights or gauges so that possibility dropped way down on my list.
I'll get some ether -- I had been meaning to get some for my snowblower anyway. If problem #1 recurs I suppose I could leave the key on, give it a squirt, and then crank again. For problem #2 it's clearly getting enough fuel it start and run for about a second before quitting, so what would I be looking for -- a longer run with ether?

Different starting problems with cold vs hot engine seems like a vital clue, but I just can't figure out what it is telling me. After many years of trouble-free starting, having both problems pop up within weeks of each other suggests a common fault, but I'm stumped. Spark or fuel?

 

I don't own a fuel pressure gauge, by the way. I should get one.

 

#2 could be the fuel pump NOT coming on, and engine is starting using residual pressure in the system, so starts and then dies

In START position the ignition switch needs to still power the spark and fuel systems, so its different than in the RUN(on) position, so ignition switch would still be on the table


2001 Ranger will have 55psi fuel pressure, when running, 50-60psi is spec
With key OFF pressure should hold above 20psi for MONTHS and MONTHS..............and MONTHS, lol

When key is first turned on the computer runs the fuel pump for 2 seconds ONLY, its a safety thing
2 second run time will add approx 10psi to current pressure
You can cycle key OFF and then ON, and EACH time you will get another 2 second run time, this can be good for testing and also to check if pressure is dropping to 0psi with key OFF, causing a no start
In 2001 there is a fuel pressure regulator in the tank and a check valve on the fuel pump, either can fail and cause loss of pressure when pump is OFF

 

The problems have not recurred since I took those actions:
"replacing the battery and disconnecting and reconnecting those connections normally held together by a bolt (ECU and one other, I think)."

I have enough confidence in the truck at this point that I am starting to travel back into the mountains beyond cell phone range.

Wish me luck!

 

Good luck

But I think you got it fixed

 

Crap! Problem recurred in single-digit temperatures, deep snow away from home.
The connector next to the ignition module (with the bolt) has white powdery corrosion on all pins. Took it on and off a couple of times, started and made it home.
Any advice for cleaning and protecting? I can get a q-tip between the pins but I don't know if I should dampen it with moisture or some product. I'll try dry first and blow it out.

 

Get a spray can of Contact Cleaner, also sold as MAF cleaner(although costs more, lol)

Spray both sides of connector, pins and slots
You can use Q-tips for better cleaning

Plug in and unplug connector a few times after spraying to help clean off connections
Let it dry

Get some di-electric grease, its a non-conductive grease, used on electrical connectors to displace air and seal connector from moist air coming in and starting the corrosion
DO NOT get this grease on the Metal Pins or Slots, as these NEED TO conduct electricity, lol
Just put it on the plastic parts of connector so it can seal it when the 2 halves are connected

 

Thanks.

I forgot to mention, no codes when I scanned it.