The pump should run while cranking even if the inertia switch is bad.

Check the under hood fuel cutoff relay for power in and out of both sides of the socket according to the second diagram.
Check beneath the socket for corrosion.
Same for the double pole tank selector relay.

Because of its orientation moisture causes problems.

If all is good according to the schematic, swap the relay for any of the others with the same pinout.

 

if the inertia switch is tripped no fuel will pump, even when cranking.at least on mine that what it does.

 

As I said, look at the schematics in post #5 above.
The pink/black wire from the ignition solenoid bypasses both the inertia switch AND the oil pressure switch.

 

I will look for it sunday the fuel cutoff relay and see what I can find.and post back my results

John

 

you are right..i'll have to check my truck,when mine tripped mine would not start.have to make sure P.O. didn't mess with more of the wiring.lol
thanks.

 

'86bigred
Your blue fusible link could be burned out or the back feed diode could be blown.
Test the pink/black wire for continuity in both directions.
It should feed only from solenoid to selector relay according to that factory schematic.

 

When the inertia switch on my 1986 Daily Driver Tempo got tripped, it started ONCE and
ran for maybe half a second, there was no way the thing would start again. Ya know how
the fuel pump sometimes runs for a few seconds when you first turn the key on? That
wasn't happening.

I don't know anything about the wiring of these devices in trucks.

 

We changed the rear fuel pump, and found that the oil sending switch , someone hooked up a gauge and the oil line was broken and leaking, we fixed that and all of a sudden the fuel pumps work and we had fuel up that stupid intake return valve in front of the carb, fuel filter was filled with gas but was not getting to carb at all.

I took it apart and cleaned it out several pieces of metal fell out, re put it back together hooked it up and guess what the pumps stop working again!
No fuel into the line or to the fuel filter at all again?

You turn the key and you can not hear any buzz from the electronic fuel pumps at all,completely silent, and no gas flowing again?

frustrating as hell,we had it almost there, it actually idled for about 1 minute after we fixed the oil line and put in the new rear pump.

Something strange happened with the ignition switch, I had to re charge the battery from cranking it so much, after we did that the key was out of the ignition but when we connected the battery to the terminal it kept trying to start the truck and crank the engine.
We had to put the key into the ignition and re-turn it off to stop it from doing that?
Could it be something as simple as the ignition switch is bad?

Dr John O

Also where is this mysterious <!--[if gte mso 9]><xml> <w:WordDocument> <w:View>Normal</w:View> <w:Zoom>0</w:Zoom> <woNotOptimizeForBrowser/> </w:WordDocument> </xml><![endif]-->tank selector switch I read in one book it was an automatic setup and you could not select the tank your self, but the ford service manual says it a manual switch to change between the front and rear tank? Some kind of a blue switch that I can not find anywhere on my truck?

 

The switch that's on the dashboard, or the selector on the frame rail???

 

If the solenoid kept cranking it's either because you were holding it too long and the contacts inside welded together or the switch at the bottom of the column is bad/misadjusted.
Next time it does that try taking the small red trigger wire off the solenoid.
If it stops you know the switch is faulty.
If it doesn't, give the solenoid a rap to try and jar the internal contacts free.

 

From Franklin2's diagrams:


The trigger wire Jim is referring to is #5 in the diagram, should be a small red/blue-stripe wire.

 

Both actually, I know where the 6 port fuel tank selector valve is on the frame rail, but I have no tank selector switch on my dash?

Can any one take a picture and post it?

Also where is the tank selector relay?


Dr John

 

The relay should be high on the firewall under the hood by the hinge.
I can't take a picture of mine because I have a later styled dashboard, but on mine it is adjacent to the wiper ****, next to the steering column.
Yours is on the other side of the column IIRC. It's been awhile since I had my '86.

 

I read that there are 2 options for 1986 for tank selector 1 on dash, 2 automatic ?

Where would this automatic tank selector switch be and can I change it to the manual one?

hoe do I post Images on my posts?

Dr John

 

Supporters can link to photos in their gallery.
Others need to host their pictures on Photobucket, Flickr or some other photosharing site.

There's a subforum to answer just that question.
User Gallery & Picture Display Help - Ford Truck Enthusiasts Forums