Hey All,
Picked up a 1986 Ford Ranger for cheap and am trying to get it started. I bought it as a project truck. I am not much of a mechanic so I am using a few neighbors and the web to get some ideas. It cranks and will start with starter fluid. I don't think fuel is getting to injectors. I pressed the pressure relief valve on the fuel rail and just a drop of fuel came out then it was dry. My research shows it may be a fuel pump relay, fuel pump regulator, fuel pump, or fuel filter. Trying to figure out what to test next. Any thoughts?

 

Welcome to the forum

1986 Ranger
What engine?

1986 will have two fuel pumps
One in the gas tank and one in the frame rail drivers side(under drivers seat area, but under the cab)

Turn on the key and listen, both fuel pumps should run for 2 seconds, turn key off and on as much as you want until you either hear a pump or confirm no pump noise
They are not that quiet, should hear a HUMMMM


If you don't hear them HUMMMM
In 1986 there will be two or 3 relays on the battery side of engine bay on the inner fender
One will have a Brown Base, one a GREEN base, and if you have A/C one with a Black base.

Brown base is the EEC(PCM) relay, it should "click" when key is turned on, this powers the EEC(computer), fuel injectors, spark system, and fuel pump RELAY(not the pumps)

Green base is the Fuel Pump Relay, Computer turns this relay on for 2 seconds each time key is turned on

Picture of crusted up relay bases here: http://www.mre-books.com/temp/fuelinj/fuelinj013.jpg
Brown and green

What the green one should look like here: https://i.ebayimg.com/thumbs/images/...dFo/s-l225.jpg

You are dealing with a 31 year old pickup truck so will have some wiring issues, kinda goes with the age

Find the relays and pull them out of their bases, also look over the wires IN the bases
You will need a Volt meter for the next bit
Set Meter to DC volts, touch black probe to battery negative and red to battery positive, should read 12.3-12.8 volts, remember what it is, depends on batteries age
Key OFF
Black meter on battery Negative
Red meter into each slot in Green base, one at a time
Only 1 slot should show battery voltage, thats from a Fusible Link, if no 12volts then fusible link is blown
Fusible link is connected to starter Relay(solenoid), follow battery's positive cable to the Starter Relay, there will be several other wires connected to the same post on the relay
One of them will be the other end of the fusible link that goes to Fuel Pump Relay

If you find the 12volt slot then remember it
Turn key on
Test slots again
There should now be one more slot with 12volts
If not check Brown based relays wires, the Red one

 

Thanks Ron for the very detailed information, it is very much appreciated.

My Ranger is a 2.3 L gas powered.

I had a couple of follow-up questions. When I insert the key in the ignition, I get a very high pitch buzz in the cabin of the truck. Any thoughts on that? Wasn't sure if it could be related to the fuel issue.

Also, the relays are extremely hard to get apart. Do you have any suggestions or tricks on how to better take those apart.

 

Reads like relays may be corroded, almost welded together, you could test wires from the back side................but
Almost better to pry them apart and replace what needs to be replaced, bases and relays are not expensive

Does the "buzz" go away after engine starts?

Not sure if 1986 had "key in" door open reminder or seat belt reminder, but those "chimes" can fail and they make a buzzing noise when they do

Could be a relay as well, but it would effect whatever it is controlling so is everything in the Cab working?



Also one other thing on fuel pump power
In the cab, passenger side, under glove box area is the Inertia switch
Inertia switch has a weight inside, if there should be a sudden stop or roll over(i.e. accident) the weight will shift and break the electrical connection inside
The electrical connection is Fuel Pump power, so a safety switch
Looks like this: http://www.fixya.com/uploads/images/4A37D3B.jpg

It is just a pass thru for the power going to both fuel pumps, it may have 2 or 3 wires, if fuel pump fuse(fusible link) and fuel pump relay are working then these wires should have 12volts for 2 seconds when key is turned on.
Inertia switches have a RED reset button on the top, it it is up then push it back down and replace it, once they are "tripped" they can trip again with even the smallest bump.

Power for fuel pumps is like this

Battery--------fuse(fusible link)---------relay------------inertia switch(in cab)----------high pressure pump(in frame rail)-----------low pressure pump(in gas tank)

There will be a Splice, 3 wires, near the high pressure pump, 1 wire is from the inertia switch, then 1 wire to high pressure pump and another wire to low pressure pump

 

Thanks again Ron, this is great information. Is it easy to find the relays to replace? I went to autozone yesterday and then didn't have a replacement for the brown relay. Do you have a website you recommend for 1986 Ford Ranger parts?

 

relays should be standard automotive relays, 12volt 30 or 40 amp rating, same with the bases, you can mark the bases so don't need Green and Brown

You can use 4 or 5 slot/pin relays/bases you only need 4
2 wires that active relay(the 12volt rating)
2 wires that pass power when relay is Closed(the 30/40 amp rating)

 

Thanks again Ron for the info. I have one relay and another on order. I did notice the fuel pump harness has an exposed wire so I think I will have to replace it as well. Is there an easy way to put the existing wires into the new harness or is it better to splice the wires together. As a novice to wiring I'm not sure how the wires are connected in the actual harness, some clip or something.

 

Hey All,

Still trying to troubleshoot the crank but no turn over issue. I did replace the PCM and fuel pump relays. Still troubleshooting the fuel pump. I think I may have an electrical issue. With a charged battery, I turn the key into what I think is the accessory position which should be enough to get the lights on and other dash signals and I get nothing. I am pretty sure in every other car I have owned I can turn the key to accessory position and get some power. Any ideas?

 

ACC should allow Radio, and power windows use, no dash lights for engine should come on.

Main purpose for ACC was back when we used points and electric chokes.
Leaving key in RUN without starting engine could fry the points and would heat up the choke so it was open all the way, when you did try to start cold engine it would run like crap until it heated up, because there was no Choke

Ignition switch is under the steering, key slides this switch into its 4 positions, ACC-OFF-RUN-START

 

Okay so now I am really perplexed. The truck will not start. However, it will only crank when the light switch is in a particular position. If I move the light switch the truck won't crank, if I move it just right, it will crank. The light switch seems to have 2 positions, can push it in for 2 positions. Lights are not working so I really can't tell if they are on or off. Any ideas? Not sure how or why the lights being on or off would allow the truck to crank or not.

 

Well a 1986 could have had a few owners, and every one likes to add "custom" wiring, lol.

So could be a few things.
Light switch should have power all the time, same as brake lights

Someone could have spliced wires looking for full time power for CB Radio or ???
And by passed ignition wire that powers clutch or trans switch which allows starter motor to work
So power for starter relay is coming from light circuit
And if lights are not working then splice has gone bad

Power for starter relay looks like this

Battery------------ignition switch(under steering column)----------Clutch/trans switch---------------Starter relay(inner fender)------Ground

Starter relay is also incorrectly called starter solenoid, lol.

So it is all power, no ground except at the relay

 

It turns out that the headlights do work which is great. The truck will crank but won't turnover. In regards to you wiring comment, is it worth it to rewire the truck, it is super basic, no power anything. I thought it might eliminate some of the troubleshooting or then again it could be wasted money. I did replace the fuel pump, that hasn't helped yet.

 

Still trying to troubleshoot the crank but no turn over issue. I did replace the PCM and fuel pump relays, the fuel pump, and and bypassed the inertia switch, still cranks but will not turn over. When I bought the fuel pump I also bought a fuel filter. As I was getting ready to replace the filter I realized I had a different setup, I believe I have a fuel reservoir assembly, 2 hoses coming in and 2 hoses going out. So much for a basic fuel filter, lol. From what I have read, I have a few options and there may be more. Replace the fuel reservoir assembly with one that contains a filter (more expensive), one that does not contain a filter (less expensive), take apart the existing assembly and replace the O ring and filter. Any thoughts on this would be much appreciated, also any mods that would make more sense. Thanks!!!

 

Hi All,

I was able to connect the inline fuel pump to the battery and the pump ran but the truck would not start. The truck would still not start. I took the bed off the truck and am looking at the in tank fuel pump. Is there a way to direct connect test it with the battery? There are 4 pins, not sure which of the pins are hot to test the pump. As I mentioned before, I am having issues with the fuel relay so I am trying to isolate and test with battery. It looks like the in tank pump is original so I should probably replace it anyway. If I do replace it, I still need a way to test it without the relay wiring working.

 

Hi All,

Any help would be greatly appreciated. Here is the status of my truck now. I have installed a new pump in the tank, a new filter, and a new in line fuel pump. I tried to replace the FP relay and had to cut the pigtail I got a new pigtail and new relay, still wasn't working. So I connected the blue/orange wire in the relay bundle to positive battery with a wire and both pumps ran fine, still no start. I depressed the shrader valve and fuel was spraying out which means I should have fuel at the rail. I know I still need to figure out the relay issue but is there any other way to see if the truck will start. It does run with starting fluid.