Vehicle: 2003 Ford Ranger XLT Fx4 off-road, 4.0L V6 SOHC, Auto xmsn, elec. 4wd. 99,000 mi.

I'm at a loss. Originally the issue was stalling at low speed and low demand. I had earlier suspected the fuel pump was going out. I replaced the fuel pump. I didn't tighten the ring tight enough so the "check fuel cap" light came on and fuel would pour over when refueling. But the stalling issue did go away.

Fast forward one month. While casually driving, the engine started behaving erratically. Bucking, jerking, misfiring. Read the codes. Cylinder 3 and 6 misfire (the two aft cylinders). I started throwing parts at it. Everything is old and beaten by 17 years NY salt treatment.

Replaced plugs, wires and ignition coil pack. Idle was still trash after this. Misfiring continued and was running rich as heck.
Replaced the fuel injectors. Wrong ones initially (obviously that didn't work). Put the right fuel injectors in. Installed new intake man gasket and new hardware. Now it won't run and sounds like the timing is off (how??)
Replaced the camshaft pos sensor. No change. Also my battery kicked the bucket around this time (was old anyway).
Replaced the crankshaft pos sensor. No change. I replaced the fuel filter again and installed a new throttle body gasket. I also tightened down that fuel pump lock ring, finally.

The only ideas i have left are "faulty alternator", "failing PCM", or some wild internal engine catastrophe that I can't imagine.

Oh BTW, no timing chain "ding ding" sound ever. Please help. Any idea, no matter how outstanding would be nice to hear. Thank you!

 

Welcome to the forum

Use the 50/50 test, been around since the 1890's, first gasoline engines, still the best test there is for a crank but no start
Spray gasoline or ether(quick start) into the intake and try to start engine
If it starts and then dies you have a fuel delivery issue
If it doesn't start then you have a spark issue
50/50 instant results

Only sensor that is used for start up is the crank sensor, and there is a simple test to see if that is working and if computer is working
Turn on key, CEL(check engine light) will come on IF computer is booting up
Turn key to START
CEL should go OFF as starter motor is turning the crank shaft and crank sensor is sending a good pulse to the computer

Other sensors are only used after startup and engine is running

After 50/50 test
And engine starts but dies

Fuel pump
When you turn the key on the fuel pump will run for 2 seconds, only 2 seconds its a safety thing, but you can HEAR IT in the cab, its not quiet, "Click, HUMMMM" then off
Turn key off and on as much as you like to see if you HEAR the fuel pump running
New just means NEVER TESTED now-a-days, not "it works" so grain of salt on "new" parts, never trust them, EVER

If you don't HEAR the pump then check it's fuse in the engine bay fuse box, FP Fuse, new pump may have blown it
When you turn the key on, TWO relays in the engine fuse box should "click", PCM relay, and the FP relay

 

Thank you for the advice. The fuel pump hum was present during all of my troubleshooting. However it is really brief, like half of a second probably.
I connected a pressure gauge at the shrader valve on the fuel rail, and it read zero no matter what. I checked to see if maybe fuel wasn't passing through the lines, but fuel had come out of the gauge when I disconnected it. I guess that means the fuel pump is only pushing enough to bring fuel to the line, but not pressurize it.
Suppose I'll buy another new fuel pump, after I try to warranty the one I got from Autozone.
I'll post an update once I've made the replacement.

 

With fuel pumps, in my opinion, its better to pay the extra for Motorcraft, they are tested at the factory before being boxed and shipped, which is why they cost double or triple the price of 3rd party
If its an easy to change part I do 3rd party and save the dough, but to me the fuel pump is a pain in the A to change

Flow but no pressure could be the pump, but could also be the fuel pressure regulator, which is in the tank on the fuel pump assembly, its the round thing about 1/2 way up

 

Update. Fuel pump replaced. Went with Motorcraft this time. Fuel pressure restored. Still no start.
Noid light confirmed the pulse to injectors from PCM is present.
Oh, forgot to mention, she'll run on ether. Like actually run for a couple seconds after i let go the ignition.
Not really sure where to go from here... guess I'll test every sensor I can get my multimeter on.
Any clue where to start? Was thinking MAF and TPS.

 

If it starts and runs by adding fuel manually then spark and spark timing is OK
So its a fuel issue

There is no "sensor" that can cause a no start except the Crank sensor and you wouldn't have spark if that sensor was bad

Whats the gas in that tanks history?

I assume a new fuel filter, but if you have above 30psi fuel pressure at the injectors it should start, unless its not "gasoline" that's going thru the injectors
If you think injectors are opening, noid light test, then pull a spark plug after cranking and smell the "gasoline", maybe light end of the spark plug with a match to see if it burns, it should if is "gasoline"

 

Well she runs. HUGE thanks for all your help.
The gasoline that I sucked out of the tank was a poor color and didn't really smell right. After putting new fuel in and cranking the engine for a little while, runs terrible. Probably from the bad gas and the damage it may have caused... Also my PCM is probably freaking out, it hasn't run in four months.
I did what I could to clean the tank while still mounted to the truck, looks good in there.
Any advice for follow up maintenance? Now knowing that bad fuel was an issue, I wonder what other damage may have occurred. What treatment options are there?

Again, many thanks for your guidance. I most likely wouldn't have blamed the gasoline for no start.

 

Good work

No damage, just run a can of Seafoam, or similar fuel system cleaner, as per instructions on can with the new gasoline, follow instruction as per gallon of gas, more doesn't work better, lol
And maybe another can of cleaner on the next tank

I would change fuel filter now and then again in a month or two

You can take the vehicle in to have the injectors flushed and cleaned, but I would leave that until you decide the cleaner didn't help

Did you pull a spark plug?
And how did the tip look, was it still shiny clean, if it was a little black then I would clean them all now that there is good gas in the system

 

Read somewhere gasoline is generally only good for about a month. Longer than that and additives start breaking down. It can accumulate moisture, etc. It may still run, it's just at it's best for about a month or so. Dont think I've seen it get so bad it wont run except in a lawnmower that's been sitting out for a year. But I've seen cars run rough from old gas.