To put a long story short, I bought a not running, hight mileage 1994 Ford Ranger off of a friend for a very reasonable price.

He included all of the parts needed to fix it, claiming it only needed the fuel lines and fuel pump replaced.

I have the bed off, I have replaced the pump, and fuel lines, I also had to replace the battery due to it being dead after the truck was stored for an extended period of time.

I now have the enging turning over, it has compression, it also has spark, but it won't start. When I press the shrader valve on the fuel rail there is 0 pressure, no air or fuel comes out. I also cannot hear the fuel pump prime when I put the key into the "on" position.

I have checked the fuel pump relay by swapping it with another one, I also can feel the relay energize when the key is turned into the on position. I have also jumped 12v power wire like in this video . I still had no power coming from the fuel pump. My multi meter also confirms 12v power under neath where the relay is.

I checked the inertia switch, the button was fully depressed, although I did not check it with a multi meter.

One thing I have noticed, I don't get any check engine light illuminated in the dashboard when I turn the key into the "on" position. Would this mean there might be an issue with the PCM? I figured the PCM is working as I am getting spark when the engine is turned over, meaning the PCM is firing the ignition coil(s).

With the key in the "on" position, I checked the wiring with a multi meter back to the fuel pump, all I can get is 8v of power on 1 of the 3 power wires going to the fuel pump (the 4th wire being ground)

Any thoughts? Common issues? Wiring guides I can follow to track down this issue? I would love some insight, I can't wait to get this engine to fire up.

 

I'll start by asking what size of engine it is.
I'll also go through some of the things that I can think off, but others may need to chime in here.
Did you test the new fuel pump outside the truck to see if it actually worked ?
If your not getting the CEL, then the harness to the PCM may need to be removed and the contacts be cleaned _ the grounds too.
MAKE SURE AND DICONNECT THE BATTERY FISRT.
Could be just a burnt out bulb, but if the truck has been sitting for a while outside, then you may need to go through and clean up the engine bay grounds _ the small ones on the fire wall too.
You didn't say if you changed the fuel filter.

 

engine is a 2.3L, manual trans 4x2.

Fuel filter is new, I did not bench test the new pump, but I suppose I can remove it and test it when the weather clears up outside.

does the PCM also control spark? because I do get spark when cranking the motor over.

 

PCM controls everything, but if there are bad connection coming from it, then all things may not work _ the CEL bulb not coming on should addressed to eliminate that item.
I'm assuming that the box is still off, it's probably not the pump, but because it's such a bear to get at, testing first would be a step that I would have done.
Is it a Ford pump or after-market ?

You also measured the actual voltage to the pump and it was only 8 volts.
I'll have to see if that's right, but I don't think so.

 

Bed is still off the truck, it needs other rear suspension work so I figured I would address everything after I got the truck running.

8v power is going to only 1 of wires, the orange with a white stripe, the other two power wires (black with yellow stripe, red with black stripe) are 0.0V

Its an aftermarket pump. I would love to find out which wire activates the pump on the top of the fuel tank, I can jump 12v power to it from a known good battery and see if the pump fires up.

 

I PM'd Ron, he's the go to guy for answers around here. I got the ball rolling, so please wait, he's pretty good with answering posts.
And about the pump, most aftermarket last about a year, the Ford ones cost more, but then you're not replacing as much.

 

Wow, thanks man.

I had no choice on the pump, the PO replaced it before I took ownership of the truck. I will keep this in mind though.

 

The computer monitors fuel pump power at the inertia switch, in cab, passenger side footwell area.
Computer only sends 12volts to inertia switch for 2 seconds when key is first turned on.
After that 2 seconds, if key is left on, you will see 5 to 7 volts on the fuel pumps power wire, that voltage has no amps, it is just the monitor voltage from the computer.

So your 8volt wire is probably the wire from the inertia switch in the cab.
This was usually a Pink/black strip wire in '94, but can be different.

The fuel level sender(in tank) wire(yellow) does get 5volts from fuel gauge BUT(big but) it is Pulsed 5 volts so doesn't show up on most digital volt meters.

The fuel pump and the sender each has a Ground wire as well, so total of 4 wires
They were usually both Black but sender ground could have Black/yellow stripe.

I would locate inertia switch in cab.
Google: Ford inertia switch pictures

So you know what you are looking for, it could be just above carpet under glove box or behind passenger side kick panel
It has a rest button on it, but inertia switch is most likely OK if you were getting that 8 volts at the tank connector

Ground volt meter and hook up its red probe to either inertia switch connector
Turn key to ON and you should see 12volts for 2 seconds, then the 5 to 7 volts after that
Than means fuel pump fuse and fuel pump relay is good
Repeat test but connect red probe to the other connector on inertia switch, just to be sure it is passing the 12volts

Inertia switch is there in case of an accident, if there is a sudden stop or roll over the inertia switch will "pop" and cut power to fuel pump, reducing the chance of a fire.
Once they "pop" they can be reset, but should be replaced as they will be easier to "pop" again, i.e. slamming a door or hitting a speed bump

Wire coming from the fuel pump relay to inertia switch should be Dark Green/yellow stripe

In 1994 the computers monitor wire(5 to 7 volts) could also be located at the Relay end, so if you only see 2 wires at inertia switch that is OK

Power for fuel pump
Battery-----------30amp fuse----------fuel pump relay-------------inertia switch---------------------------------fuel pump-----Ground

 

Thank you so much for the response!

I jumped power directly to the pump. It does run and I was able to start the truck running the fuel pump jumped. When I checked the inertia switch it wasn't tripped. However, I ran my multi meter on the red wire with black stripe and got 0 volts. The green wire did exactly what you said it would. 12v then 8v.

Fuel pump relay? Or what should I trace from here?

 

If you got 12v then 8v on one terminal of inertia switch(green wire) and other terminal(pink or red wire) was 0v then replace inertia switch, it is bad.

These rarely fail unless they were tripped in an accident, so have a look around the front of vehicle underneath to see if there is any evidence of a repair

 

I disconnected the wiring harness from the switch and inserted the multi meter probe into each port on the wiring harness, switch not connected, should I have done this test with the inertia switch still connected? One of those details....

 

Yes, connected
The green wire is passing the 12volts to the Pink or red wire, thru inertia switch, which is connected to the fuel pump at the other end

If you apply 12volts to the red or pink wire fuel pump should come on, key on or off won't matter, it is a direct wire to the fuel tank connector

You could also test pump connection with OHM meter
Select Lowest OHMs on meter, 200 usually
Ground either meters probe, with inertia switch wires disconnected touch other probe to red or pink wire
Should see under 2 ohms, that means pump wiring is OK, power and Ground

 

It lives!!!

Turned out to be the pink/black wire, I was getting power at the inertia switch, but not at the pump. I ended up running a new wire from the switch to the pump and it fired right up!

I am getting a random misfire now, although it's the first time it ran, it ran smoothly up to normal temperature then started missing, although I only put about a gallon of fuel in the tank. I also found a vacuum leak, so it was idling a bit rough. But it ran on its own for about 10 minutes with ease

 

Good work

Clean the MAF sensor

Put some gas in it and Seafoam injector cleaner.

Run that gas thru the engine and see if it starts to run better in Closed Loop(warmed up)

 

Sorry for the slow response, but I finally had a chance to start putting the truck back together.

Still have this closed loop issue. It fires right up no issues, fuel pump primes, motor fires and idles at open loop without any issues, I can even rev the motor to the moon without any problems. But as soon as it wants to come down to its regular idle it starts to sputter and misfire, when I try to rev the motor up it sputters but I can get it to hold abou 1000 rpm with my foot on the throttle.

I can hear a small exhaust leak under the manifold, I have removed the throttle body and IAC and cleaned them with carb cleaner with no change in behavior. Spraying carb clear around the intake mating surfaces shows no change in idle nor is the truck hunting for an idle, so it doesn't seem to be a vacuum leak of any kind.

I'm not sure if this is a factor. But the fuel filter looks ******* old, and I'm only running about 1 gallon of fuel in it right now. Is it safe to assume I should get at least 5 gallons of make sure the thing is getting even fuel pressure in closed loop?

 

If it won't run in closed loop _ maybe the oxygen sensors need replacing and or they have a bad connection.

 

Fuel pressure is fuel pressure, open or closed loop would either both be effected or neither would
PCM has no fuel pressure sensor or any way to control it.

You just have the one O2 sensor on a '94 2.3l, so will effect the whole engine.
They need to be replaced every 100k miles so if miles are high then not a waste of money.

Fuel filter should be replace every 5 years or so

I assume the Check Engine Light(CEL) works, come on with Key ON, then goes off after engine start.

And no CEL after closed loop?

 

you said you had no cel light at first correct? is the bulb burned out by any chance? after sitting an extended period of time you may need to pull and clean the fuel rail and injectors...does it have that old gas smell? have you checked to see what the fupressure is? check plugs and wires as well