Is it holding pressure after ignition off?

 

Yes it did seem to be holding pressure.

 

I shall go and check after a bit. I believe I left the gauge attached.

 

Did you replace the fuel filter, I went through the thread again and you never did say ?
Make sure the connection is clean and secure on the crank shaft position sensor too.
Pull the connection and inspect for corrosion on the contacts.

 

Has a new CPS and has new fuel filter and it is holding pressure after ignition off for 4hrs now. MAF is about the only electronic sensor that hasn’t been replaced. It doesn’t look to be dirty though.

 

Did some more reading and found this.

https://www.ranger-forums.com/4-0l-o...6/#post2125403

When it was running, and with the engine fully warmed up, did it run properly ?
The link may suggest a faulty coolant sensor.
If it's not working the ECM has no way of telling when the engine is cold and t won't be "choked".

The sensor is located on the lower intake manifold at the front.
It looks like the temp gauge sensor, but will have two wires coming out of it, not just one.

EDIT:
What's your compression too ?
That should be ruled out as a possible cause.
How many miles in on it ?

 

Doesn't matter what "they" add to the outside of a gasoline engine the engine just needs 3 things to start and run

1. Compression, above 120psi
2. Fuel, in the right mix with air
3. Spark, at the right time

So for now forget sensors or controls, forget anything electronic

50/50 test, Adding fuel manually to the engine
Remove large air tube from intake end, just a clamp to loosen
Open throttle and spray in gasoline or Quick Start(ether) into the engine
Try to start engine

If it starts and dies then fuel is the problem
If it doesn't start then Spark or compression is the problem
50/50 simple and fast

Once you know where to look THEN and only then can you start diagnostics

There is no tool or computer on this planet that can diagnose engine problems better than your brain and a little common sense

So don't guess, do the 50/50 test

If 50/50 test seems to complicated then do this
Crank engine over 3 times, count to 5 each time
Pull out 1 spark plug
Look at it's tip
If wet with fuel then spark/compression is the problem
If dry then fuel is the problem

Common sense is best tool in the box

 

Two things are needed in the fuel system. Pressure and volume. Pressure is only half the story.

Have you changed the fuel filter? Easiest thing to start with.

 

Post 30.

 

I’m having the same problem. Reading this thread, I tried some of the diagnostic procedures. I replaced the relay. I replaced the fuel pump because I was certain that’s what the problem was. I have electricity at the plug to the fuel pump. I can’t remember which forum, a guy said, hook up your multimeter to the pink and black wires, turn the key, it’ll go to 12 V for two seconds and then drop to 6 to 8 V. It did that. I took the fuel filter off and directed the hoses into a container and turned the key, no fuel spewed out. I opened up the air intake and sprayed starter fluid and it did turn over, obviously it didn’t run. So I know I have spark. I haven’t tried the Schrader valve at the fuel rail because it doesn’t seem like it’s sending any fuel at all. When I turn the key, I don’t hear the fuel pump.