Cranks, but won’t start. Not getting fuel

[Michael_shymkus]

So I’ve got a 94 4.0 and a couple months back I had came back from vacation and went to drive the ranger. Started great and idled normally, got 3-4 miles down the road and it starts jerking bad and rpms are dropping. Dies a couple times, but I could get it to start right back up and limp it home, doing the same thing over and over.

so now it won’t even start, it’ll crank but won’t start. I believe it’s not getting fuel somewhere, sprayed fuel directly into it and it started and ran until stopped. I’ve replaced fuel pump, fuel filter, fuel pressure regulator. And still nothing. Brake lines look fine. No leaks or anything. Also, the “inertia switch” is good. Kinda stumped what to do now. Thanks for any input.

 

[RonD]

Welcome to the forum

Do you hear the fuel pump run for 2 seconds when you turn the key ON, its not quiet, a "click" HUMMMM "click" then off
You can repeat key off and then on as much as you like


1994 is OBD1 so there will be a jumper slot you can use to turn on the Fuel Pump relay manually to test it
Look here: https://www.therangerstation.com/tech_library/OBD_I.shtml

second drawing is the OBD1 test plug in the engine bay, in 1994 4.0l it should be next to the fuse box on the main wiring harness, it may have a cap on it that says "EEC"

The fuel pump slot is labelled in the drawing, that is the Ground that activates the fuel pump relay if key is on
You can test it first with a volt meter, that slot should show 12volts with key ON
That means FP relay is getting 12volts from EEC relay, as it should
Now use a Jumper wire in that slot and to a Ground, if key is on you should hear the FP relay "click" and the fuel pump come on
FP relay is in the engine fuse box, so easy to hear it "click", if key is ON

You can try to start and run the engine with jumper in place, this is what the computer does, it grounds the FP relay to send 12volts to the fuel pump
This slot is that Ground wire from the computer

If grounding the slot does get engine running then you could have a computer issue, I just had an issue with my 1994 4.0l computer, had to replace the 3 capacitors inside it, at 25 years old they leaked
Only cost $5


If fuel pump is running and still a no start
Then watch the CEL(check engine light), it should come on with key ON, and then go OFF when engine is cranking/turning, this means computer is "seeing" engine turning and is getting a timing pulse from crank sensor
If CEL stays on then no timing pulse so no start
But if engine starts when you add fuel manually then this wouldn't be the issue since you have spark timing

If CEL goes off then unplug the TPS(throttle position sensor) on the upper intake, 3 wire plug
Then try to start
If TPS is shorted out the computer will NOT start fuel injectors, its called "clear flooded engine" mode, but spark would still be on

 

[Michael_shymkus]

Wanted to add, that it just started right up today. Idled just fine and then just died. Started it right up again and same thing, gave it a little gas and at about 1800 rpms is just died. Wouldn’t start after that.

 

[RonD]

Do you HEAR the fuel pump with Key On?

And have to ask.................do you KNOW that there is gas in the tank, or are you just assuming gauge is working
Chased my tail a few times with an empty gas tank, lol

There is a fuel pressure test port on the engine, looks like a tire's air valve because that's what it is, a schrader valve, works the same way, press on the pin and gasoline should spray out, so be careful
May have a screw on cap just like a tires air valve cap

On passenger side of 4.0l engine near center just below upper intake

 

[Michael_shymkus]

Yes fuel pump is kicking on, brand new fuel pump actually and yes it has a completely full tank with a can of seafoam in it. And a new fuel filter. Brake lines look good also, and new fuel pressure regulator.

 

[RonD]

Do 50/50 test
See if its a fuel or spark issue now

 

[Michael_shymkus]

Pretty sure it’s getting spark because it’ll start randomly. And we sprayed fuel directly into it and it started and ran while spraying fuel. How do you check for spark?

 

[RonD]

If it runs when you add fuel manually(50/50 test) then spark and spark timing is good
If it dies when you stop adding fuel then you for sure have a problem with fuel delivery into the intake
So pump, filter, injectors

If you have fuel pressure at the engine, use the test port to see
Then fuel injectors may not be opening which is a computer issue
Unplug TPS 3 wire connector, it can cause "no injectors", then try to start

Pull computer and look inside, leaking capacitors can cause issues, there are 3 of them, leak is obvious
Costs under $5 to replace all 3

 

[rumblecloud]

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