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HDGENE
HDGENE, Ford Senior Master/Diesel/Trans
Category: Ford
Satisfied Customers: 5434
Experience:  25 years Auto experience, Ford ,GM, Chrysler, Asian & European
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1994 ranger 4.0 no power to fuel pump
, no start no inj

Customer Question

Customer: 1994 ranger 4.0 no power to fuel pump
JA: Thanks. Can you give me any more details about your issue?
Customer: no start no inj pulse has spark
JA: OK got it. Last thing — JustAnswer charges a fee (generally around $28) to post your type of question to Ford Experts (you only pay if satisfied). There are a couple customers ahead of you. Are you willing to wait a bit?
Customer: i guess
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Submitted: 1 year ago.
Category: Ford
Expert:  Eric replied 1 year ago.

HI,

Ok, is the inertia(fuel cutoff) switch tripping or staying in the on position?

Is there factory or aftermarket anti theft system on your Ranger?

Customer: replied 1 year ago.
staying on no theft
Expert:  Eric replied 1 year ago.

HI,

Ok, and no power to the fuel pump Or the injectors - both lack signals, correct?

Customer: replied 1 year ago.
no power at pump has inj power no pulse
Customer: replied 1 year ago.
Expert:  Eric replied 1 year ago.

HI,

Ok, have you checked the fuel pump relay and the pcm main relay in the engine compartment relay box?

Customer: replied 1 year ago.
flipped them with each other nothing
Expert:  Eric replied 1 year ago.

HI,

Ok, the fuel pump and injectors are on different circuits and there are only 2 common denominators - the pcm main relay and the pcm. If the relay is good, then it is a faulty pcm. I see nothing else in the wiring diagram that ties into both

Customer: replied 1 year ago.
a faulty pcm relay would cause no pump power and no pulse at inj? also your saying a faulty pcm could cause the same? either or could cause this and only these two items if i try a new relay dont fix it then bad pcm?
Customer: replied 1 year ago.
noyhing with wiring?
Expert:  Eric replied 1 year ago.

HI,

The pcm relay sends a signal to the fuel pump relay, which is why it could cause both issues as it being bad means no signal to the fuel pump relay or to the pcm, thus creating no power to the fuel pump and no injector pulse as no signal from the pcm to the injectors to pulse.

You can check for signal to the maf sensor, vss sensor, or other sensors while cranking. If signal is to them, then wiring is fine from the relay to the pcm and we know it is the pcm

Customer: replied 1 year ago.
if i have swapped fuel and pcm relays just to test also third ac wot relay i think if it was a relay at some point switching them should work
Expert:  Eric replied 1 year ago.

HI,

If you swapped them that much, one should have been good, so we can eliminate the relay. Check for signal(power) at maf sensor, iac valve and other sensors. If you have signal, then wiring from pcm relay to pcm is good, and this leaves just the pcm

Customer: replied 1 year ago.
WHICH wires would i ck for signal on those sensors
Expert:  Eric replied 1 year ago.

HI,

Should be the red wire at the iac valve and the maf sensor.

Customer: replied 1 year ago.
what are we looking for and while cranking?
Expert:  Eric replied 1 year ago.

HI,

Should be at least 10v while cranking

Customer: replied 1 year ago.
ILL CK NOW
Expert:  Eric replied 1 year ago.

Hi,

ok, sounds good

Customer: replied 1 year ago.
10.50VTS AT BOTH 12V KEY ON 10.50 CRANKING
Expert:  Eric replied 1 year ago.

HI,

Ok, no wiring break between the pcm relay and the pcm. So this only leaves the pcm as the culprit

Customer: replied 1 year ago.
ill try tommarrow if open or sat and let you know
Expert:  Eric replied 1 year ago.

HI,

Ok, sounds good. I will be here everyday

Customer: replied 1 year ago.
ecm did not fix
Customer: replied 1 year ago.
anyone out there
Customer: replied 1 year ago.
Posted by JustAnswer at customer's request) Hello. I would like to request the following Expert Service(s) from you: Live Phone Call. Let me know if you need more information, or send me the service offer(s) so we can proceed.
Customer: replied 1 year ago.
why would i get reffered to a new mech?
Expert:  HDGENE replied 1 year ago.

Hello, let me see if I can be of assistance? Does the check engine light come on when the key is turned to on and go out when cranking? Do you have communication with the pcm using a scan tool? Any codes stored key on engine off testing?With the fuel pump relay removed do you have 2 sources of power at the fuel pump relay,one constant and one for a few seconds when the key is cycled to on? If you jump across the fuel pump relay does the fuel pump kick on and send pressure to the fuel rail?

Customer: replied 1 year ago.
HANG ON
Expert:  HDGENE replied 1 year ago.

Ill be right back, picking up some dinner round the corner

Customer: replied 1 year ago.
NO CK ENG LIGHT AT ALL scanner wont talk to ecm i have bat volts at 2 points all the time jump which ones?
Customer: replied 1 year ago.
used diff scanner no codes on second ecm other guy said to change
Expert:  HDGENE replied 1 year ago.

Ok so it wont communicate with either scan tool or it will with a second scan tool? No codes then? You have a good blue spark but no injector pulse? Will it run a few seconds if you spray carb cleaner into the intake?

Customer: replied 1 year ago.
spark looks good no pulse
yes second scanner no codes will run with spray
Customer: replied 1 year ago.
put the original ecm back in as it looks like nothing was wrong with it no codes
Expert:  HDGENE replied 1 year ago.

Ok its possible the bulb is burnt out for the check engine light, under normal operation if the eec power relay is working properly it will turn on the check engine light when the key is on. Since you can communicate with the pcm with a scan tool it should be working. When you crank the engine the check engine light turns off if you have an rpm signal which you should since you have spark. You should also have injector pulse with spark long as the pcm is getting an rpm signal. If you scan tool can look at live sensor data and look at rpm that would be helpful.when cranking it should read a few hundred rpm. The eec power relay sends power to the fuel pump relay to energize the fuel pump a few seconds. Then powers it continually once the engine is running. Here is a schematic of the system to help know where to jump across relays for testing output of the eec power and fuel pump relay.

Expert:  HDGENE replied 1 year ago.

SInce you have no ignition pulse its possible you have an open circuit in the wiring that sends the rpm signal from the ignition control module to the pcm

Customer: replied 1 year ago.
when i tun key on eec relay can be heard energizing and one terminal in fuel fump relay gets power but stays on oalong with other that always has power then i should be able to splice a wire in or test rpm wire from control mod to ecmn
Expert:  HDGENE replied 1 year ago.

One fuel pump relay wire is hot all the time, the other gets power from the eec power relay as shown in the diagram, to energize the pump you want to jump across the switch side of the fuel pump relay to pressurize the fuel rail

Customer: replied 1 year ago.
i thought one gets power for a short time with key on
Expert:  HDGENE replied 1 year ago.

One for a short time, other all the time direct from a fuse to the switch side of the relay. The coil side of the relay is energized for a few seconds to complete the fuel pump circuit by closing the fuel pump relay switch side.

Expert:  HDGENE replied 1 year ago.

One wire sends pulse to injectors 1,2,3 Tan. White wire does injectors 4,5,6 so check for pulse on all injectors.

Customer: replied 1 year ago.
that one gets power and has power at all times both have power at all times key on, jump two you said the fuel rail gets pressureized but no start
Customer: replied 1 year ago.
cant get to all injectors
Expert:  HDGENE replied 1 year ago.

Ok, Pin 30 for the fuel pump relay should have power all the time from the number 22 fuse 20 amp in the power distrubtion box under the hood. Pin 85 at the fuel pump relay should only have battery voltage from the eec power relay whe the key is turned to on for a few seconds to prime the fuel pump. If it is hot all the time the eec power relay ground circuit from the pcm is shorted to ground and leaving it energized all the time. It could be causing a voltage drop if this wire is grounded all the time pin 86 on the coil side of the relay light blue/orange wire. Since the pcm is new id suspect a wiring issue between the relay and pcm if its not working as described.At least check both sides of the fuel rail for pulse since two wires pulse the two different sides of the coil.

Customer: replied 1 year ago.
thats exactly whats going on its power all the time unless you turn key off what pin number or color at other end at ecm you say pin 86 on coil side of eec relay
Expert:  HDGENE replied 1 year ago.

As I mentioned the rpm signal goes from the crank sensor to the ignition module, which fires the coil. Then sends the rpm signal to the pcm to fire the injectors. Either the rpms signal isnt being send from the ignition module, or wiring is bad from the ignition module to the pcm

Expert:  HDGENE replied 1 year ago.

Pin 22 at the pcm is the ground control for the fuel pump relay. light blue/orange. its all shown in the pdf files i attached

Expert:  HDGENE replied 1 year ago.

It should set codes for a profile igntion pickup signal or loss of rpm with a scan tool

Customer: replied 1 year ago.
theres two problems
Expert:  HDGENE replied 1 year ago.

Could be related possibly. Need to verify rpm signal is going from ignition module to pcm, check pin 22 for short to ground for fuel pump relay circut.

Customer: replied 1 year ago.
i asked this stuff about wiring with other guy i suspected wiring he said ecm i was scepitcle
Expert:  HDGENE replied 1 year ago.

Yes, its hard to say whats gong on for sure without checking for a short to ground on the fuel pump relay,with it being energized though it should have fuel pressure at the rail. The loss of injector pulse is most likely a bad ignition module or wiring inbetween it and the pcm to convey the rpm signal to fire the injectors, its firing the coils.

Expert:  HDGENE replied 1 year ago.

One thing to check besides the circuit is to see if the EGR flow sensor(DPFE Sensor) is shorted, this can cause odd things to happen. It is a metal block if original or black plastic with two hoses coming off the exhaust manifold, a tube with two hoses. Uplug this sensor and see if normal operation happens,just a shot in the dark. But worth checking as is unplugging the altenator.

Customer: replied 1 year ago.
i dont see a flow sensor or a egr pin 2 blue/org has no resistance
Customer: replied 1 year ago.
22
Expert:  HDGENE replied 1 year ago.

Does it have an egr valve?Some models didnt have one, was just a thought.

Expert:  HDGENE replied 1 year ago.

You dont have fuel pressure at the rail? Im sorry, the relay wont energize unless you get a ground signal from the pcm so with the key on both will be hot.Pin 22 grounds the coil side of the relay and should shut the relay and send power to the inertia switch and then to the coil.

Customer: replied 1 year ago.
i tested 22 at ecm and relay no resistance witch wire is tach signal at icm and ecm
Expert:  HDGENE replied 1 year ago.

Pin one at the ignition module should be the rpm pulse signal to the pcm Gray/orange wire. Like I said if you look at the schematic it shows all this stuff, at the last pages it shows the connectors and pin numbers. It goes from pin 1 ICM to pin 56 at the pcm

Customer: replied 1 year ago.
where are they hiding the icm
Customer: replied 1 year ago.
just found it testing wireing,can icm cause this problem?
Expert:  HDGENE replied 1 year ago.

Yes, left front radiator support. Ive given you the schematics and connectors to test the circuit.

Customer: replied 1 year ago.
i tested 1 to 56 no resistance
Customer: replied 1 year ago.
can icm be a problem
Expert:  HDGENE replied 1 year ago.

Open circuit if unplugged on both sides, should have less than an ohm resistance. If not run a wire from the icm to the pcm and retest

Customer: replied 1 year ago.
has all zeros on that wire and fuel pump wires both read all zeros
Expert:  HDGENE replied 1 year ago.

If you hold both test leads together that shoud be a normal continuity reading.Sould be less than one ohm depending on the range you have the ohm meter selected to.

Expert:  HDGENE replied 1 year ago.

If you are on mega ohm seting for instance it will show zero. You want ohms depending on the meter it will have a range selection to scale the meter.

Customer: replied 1 year ago.
both have 1.0
Expert:  HDGENE replied 1 year ago.

Ok with 1.0 ohms the wiring is good, id go with an ignition module and retest for injector pulse

Customer: replied 1 year ago.
i remember the older escorts 1.9 module when no spark or pump
Customer: replied 1 year ago.
went anyways ill try that tommarrow still cant figure how that other guy got to ecm
Expert:  HDGENE replied 1 year ago.

That I couldnt tell you off hand. Good luck and let me know if you need more help.

Customer: replied 1 year ago.
appreciate the help
Expert:  HDGENE replied 1 year ago.

No problem, just get back to me tomorrow and let me know if you got it going with the ignition module. If I was helpful remember to leave a positive rating for assisting you

Customer: replied 1 year ago.
no good with the icm
Expert:  HDGENE replied 1 year ago.

Long as its getting an rpm signal to the pcm on the pip signal wire it should have spark and injector pulse. You are sure the pcm is online, you replaced the eec power relay and fuel pump relays with known good relays?

Customer: replied 1 year ago.
im wondering if its getting a rpm signal fron crank sensor to icm since we ohm the wire from icm to ecm
Customer: replied 1 year ago.
i just swapped relays i do hear and feel eec relay energizing
Expert:  HDGENE replied 1 year ago.

If you have spark and no injector pulse it has to be gettin rpm signal to the ignition module to command the coils to fire.

Expert:  HDGENE replied 1 year ago.

Yes, but if you are swapping a bad one with a good one it can cause a different circuit fault if swapping from eec to fuel pump

Customer: replied 1 year ago.
okay still have power at two points fuel pump relay
Expert:  HDGENE replied 1 year ago.

And you dont feel the fuel pump relay click? No fuel pressure? No injector pulse?

Customer: replied 1 year ago.
right eec clicks and feel operation but not fuel pump relay even tested others in eec slot and they click operate
Customer: replied 1 year ago.
no pressure or pulse
Expert:  HDGENE replied 1 year ago.

and the ground signal wire from the pcm to the fuel pump relay ohmed ok? If you hook up a test light to the positive battery terminal and cycle the key on does it light the test light for a few seconds to indicate a ground signal?

Customer: replied 1 year ago.
we tested pin 22 to fuel relay blue/org that ohm good that has 12v with key on at all times
Expert:  HDGENE replied 1 year ago.

Then that circuit is a short to power somehow, that wire is only a ground circuit for the fuel pump relay, it is hot with the fuel pump relay removed?

Customer: replied 1 year ago.
that blue/org fuel relay wire has power at all times with key on and testing it for ground with key off it lights test light real dim
Expert:  HDGENE replied 1 year ago.

Something is backfeeding that circuit, is anything else jumpered into thhat wire as it runs off to the datalink connector? The self test connector for the scan tool.

Customer: replied 1 year ago.
nothing seen that wire runs from ecm to data conn then to relay?
Expert:  HDGENE replied 1 year ago.

Well im running out of ideas on this one, either there is a vehicle sensor that is backfeeding the pcm shorted out, or the wire for that circuit is shorted to power which is why the wire is dim.

Customer: replied 1 year ago.
unplug eec relay power goes away
Expert:  HDGENE replied 1 year ago.

EEC Power is energized with key on, it feed power to the injectors and many vehicle sensors, as shown in the circuit i gave you, you can unplug each of the sensors on the circuit and see if the powr goes away indicating a shorted circuit backfeeding the pcm

Customer: replied 1 year ago.
that wire runs fron ecm directly to fuel pump relay i unpluged just about every sensor still has power what about running a new wire outside loom?
Customer: replied 1 year ago.
in scematitc 22 ecm runs to data connector and then to pump relay correct
Expert:  HDGENE replied 1 year ago.

yes run a new wire for that circuit and retest

Customer: replied 1 year ago.
let back up a step theres 4 wires to the fuel pump realy two have 12v at all times one allthe time one when key turned on its not getting power on the blue/org the red wire is the one that gets power when key is turned on and dim light testing for ground key off blue org has no ground from 22 on ecm when key turned on
Expert:  HDGENE replied 1 year ago.

Right, that dim light pin 22 wire should not have any voltage on it, it is the ground circuit from the pcm to ground the fuel pump relay, you know when you jump the relay the fuel pump operates. Rerun that wire for the ground circuit from the fuel pump relay to the pcm and diagnostic connector

Customer: replied 1 year ago.
it doesnt im sorry i just mentioned its the red wire thats has power and dim
Expert:  HDGENE replied 1 year ago.

It doesnt have battery voltage? Less than battery voltage.You are confusing me

Expert:  HDGENE replied 1 year ago.

Thats the power supply from the eec power relay, run a new wire from the eec power relay to the fuel pump relay, you must splice this into the rest of the circuit,make sure the other sensors on the same circuit have battery voltage.If you cut the wire, it will tak away power from the other sensors, splice into it from a point of good voltage

Customer: replied 1 year ago.
lets start fresh blue org has no volts its fine two or the other 4 have power and the red has 12 volts key on and turned off tested for ground lights up dim ground
Expert:  HDGENE replied 1 year ago.

I cant keep up with the incorrect information you are giving me.WHat color is the wire that is lighing up dimly when you turn the key off, does pin 22 from the pcm show a ground signal like ii asked earlier when you cycle the key to on for a few seconds.

Customer: replied 1 year ago.
sorry red dim wire key off no ground signal from 22
Customer: replied 1 year ago.
red wire when testing if for ground
Expert:  HDGENE replied 1 year ago.

Why are you testing the red wire for ground? Thats a power supply.

Expert:  HDGENE replied 1 year ago.

Im opening this question up to another expert, ive tried what I can but I feel like we are going in circles here

Customer: replied 1 year ago.
i just happened to test it when i tested 22 for signal
Customer: replied 1 year ago.
ANYONE OUT THERE
Customer: replied 1 year ago.
you out there
Customer: replied 1 year ago.
anybody going to answer?
Customer: replied 1 year ago.
hello
Customer: replied 1 year ago.