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Category: Ford
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Experience:  ASE CERTIFIED TECHNICIAN ADVANCED LEVEL SPECIALIST. Wisconsin certified emissions state inspector
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1987 Ford Ranger Super: 4x4..fuel filter..rotor..the injectors

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I have a 1987 Ford Ranger Super 4x4 2.9L and I have replaced the distributor,pick up coil ,stator,plugs,cables,coil,fuel filter,fuel pump relay,EEC relay , EEC 2 times , ignition control module ,rotor , reset the inertia switch, changed all fuses in fuse box , and as soon as I turn on the ignition switch the fuel pump relay starts clicking non stop and the truck will turn over but will not start because there is no pulse at the injectors and no spark at the plugs, what is wrong with this thing. It will start about once every couple of days then after a few minutes start backfiring ,then die and back to the clicking and no spark and no pulse until it decides to run for a few minutes again.



I would like to help you diagnose this problem you are having with your vehicle.


Do you have a voltmeter?


Does the check engine light come on with the key in the on position?



Customer: replied 7 years ago.
No, but I am not sure if it even works, i've never seen it on.In addition to things I have replaced,I replaced the fuel pressure gauge ,and I am getting fuel to the fuel rail.I don"t have a fuel pressure tester but when I press the pressure relief button fuel shoots to the hood constantly because of the fuel pump not cutting off..After power going to the coil there is no spark on the plugs and the fuel pump will not cut off because of the relay opening and closing rapidly and I am not getting power to the injectors to make them pulse.I have hooked a code reader to the plugs on the right side fender wall,but the thing keeps telling me to plug into vehicle.It works fine on my Durango so I know it works.



Lets check one thing at a time.


Just hang in there with me.


Turn the key to the on position (don.t start the engine). Does the check engine light come on?

Customer: replied 7 years ago.
No ,just the emission light and the seatbelt light and the emission light cuts off after a few seconds,the bulb my be burnt out.
SO no check engine light or service engine soon light?
Customer: replied 7 years ago.
none.I have never seen it on since I bought the truck .

Ok... I just wanted to know if it comes on with the key in the on position.


Lets check for a 5 volt reference with the key on at the tps sensor.


Do you know where the tps sensor is?



Customer: replied 7 years ago.
no, I don't know where the throttle position sensor is.

It will be located on the throttle body assembly. It will have three wires going to it.


Let me know if you need pictures.

Customer: replied 7 years ago.

I am pretty sure I have found it,green ,black and orange wires running to it .Does the key switch need to be on?



One of those wires should have 5 volts on it

Customer: replied 7 years ago.
I have 4.89 v on the orange wire and .03 on the other two.





You said that we do not have spark.... correct?


DO we have power at the ignition coil?

Customer: replied 7 years ago.
Yes 11.62v running to plug at coil.

Ok.... but no ground signal trigger?


To check the ground signal trigger, you are going to want to use a test light. The clip or alligator side of the test light gets hooked to battery power. The tip of the test light touches the signal wire to the coil. WIth the engine cranking over, the test light should blink if the coil is receiving a signal to fire spark.

Customer: replied 7 years ago.
I really can't tell,I am the only one home yet and my good test light is at my parents house where the truck first laid down on me at and on one of the rare occasions that it started ,I drove it most of the way home before it started backfiring and then dying and some of my tools are still there,I am trying to use a test light for finding current in wires and the light is just to dim for me to see while cranking the truck.
Is there any way you can try a different test light later tonight or tomorrow?
Customer: replied 7 years ago.
yes. but could you explain exactly which wire is the signal wire?Is it the one running to the distributer?
It should be the dark green with yellow stripe wire.
Customer: replied 7 years ago.
all right.what do I need to do about waiting till later ,my wife will not be home until 7:00 pm eastern time,unless i can find some help sooner. just wait and reply when I have the answer or is there a time limit on how long I can wait?

No time limit... take your time!


I will be on line all day tomorrow!


Here is a wiring diagram.



Customer: replied 7 years ago.
O.K. I went and got my tester and hooking the clip to the positive side of the battery and putting the pointy end on the green wire side of the plug the light came on,then when I turned the engine over the light went off sometimes glowing real real faintly but no visible blink!I tried several times on the pos. and neg. terminals so I would make sure I did it right ,same result on either terminal.
SO no solid or even dim blink to indicate a ground signal trigger?
Customer: replied 7 years ago.
When I turned the engine over the light would cut off ,if I let it turn over for a while the light would come on just barely visible, too dim to tell if blinking.
That might indicate that the coil is getting a trigger to fire the spark. I would see if the parts place that you got the coil from would warranty it. I would replace it and then retest things.
Customer: replied 7 years ago.
But why is the fuel pump running all the time and the fuel pump relay clicking.It should build pressure in an instant and quit until needing to pump more fuel into the injectors which are not pulsing.Something is not telling the computer to tell everything what to do,and that is what I need to find out.No offense but I find it hard to think that every part I've bought from Autozone,Advance Auto and O'rielly's is possibly defective.Most stuff I have had checked and was o.k. but I replaced anyway.

I believe you have a wiring or low voltage issue. This can be caused by a bad/loose connection or something like that.


If you would like to approach it by going after the fuel pump relay and inputs, lets do so.

Customer: replied 7 years ago.
O.K. I do apologize for this taking so long.I am by no means an auto mechanic, but in 20 some years I haven't had a problem I couldn't figure out.I have checked everything,this has been going on for months,I have tested all fusible links I could find,pulled every connection apart and put back together I could find. I just can not figure it out.Bad thing is I know it has to be something real simple.

I would be willing to bet you are right... it is going to be something simple. We just need to find it.


If you are willing to stick with me, I will have you run a series of test so that we can pinpoint this problem. It may take a bit, but I am willing to do this if you are too.

Customer: replied 7 years ago.

At this point I am ready for anything!!



I am going to ask some silly and basic questions. Just stick with me as I will not leave you hanging. I am in the middle of dinner but I will try my best to respond to you asap!



Customer: replied 7 years ago.
If you want to wait till tomorrow ,we can,I get off work at 3:00 pm EST and we can resume there. It is starting to get a little dark here and I may not have much longer to see outside.You can send me a list of stuff to check and after I've done it I can reply.

Ok.. that is just fine.


First step is to go to the fuel pump relay and check all the wires.


Can you get me the color wires that go into this relay?



Customer: replied 7 years ago.
Tthis probobly isn't going to be much help because the wire colors are faded badly-orange with blue stripe,yellow couldn't find a stripe,red couldn't find a stripe,and what might have been green at one time but mostly tan now with a brown or red stripe.Hope this helps!!

Ok... Good!


The yellow and the red wire should both have FULL battery voltage with the key on. I want to check for voltage on both of these wires with the key on and the relay still plugged in and clicking. we are going to need to back probe these cavities to get a voltage reading because we are going to leave the fuel pump relay plugged in.


After we do this test I want to see if the voltage changes on either of these two wires with the relay unplugged.

AMEDEE and other Ford Specialists are ready to help you

Just as a side note, I came across this TSB that I thought that I should bring to your attention.


Engine/Ignition - No Start Condition

Article No. 87-20-18FORD: 1983-86 LTD 1983-87 ESCORT, EXP, MUSTANG, THUNDERBIRD, CROWN VICTORIA 1984-87 TEMPO 1986-87 TAURUS

1984-87 TOPAZ 1986-87 SABLE

This article is being republished in its entirety to expand the model year coverage.

ISSUE: The primary winding of the E-core ignition coil may be damaged if the wire harness containing the tachometer circuit has a short to ground.

ACTION: Before replacing the E-core ignition coil, perform the following diagnostic procedure.

1. Turn ignition to "ON" position.

2. Measure and record battery voltage.
Figure 50

3. Measure and record voltage between negative terminal and coil and battery ground post as shown, Figure 50.
4. If the differencce in readings is greater than 1.0 volt, check tachometer circuit for a potential short to ground.

5. If a short is present, make necessary wire harness repair.

6. Replace ignition coil as required.

OTHER APPLICABLE ARTICLES: Supersedes 84-14-18, 84-14-18-S, 85-16-13, 86-2-21



Here is a wiring diagram for your fuel pump relay.


If we have low voltage coming into the fuel pump relay on the red wire, lest go back and check the EEC relay and inputs.


If we have low voltage coming into the fuel pump relay on the yellow wire, lets go back and check the "blue" 20 gauge fusible link.