still cant seem to fix this 87 ranger 2.9...NEW fuel reg,fuel press reg,rebuilt
computer.cold it will start and run fine.then it will shut down with in 5 to 18 miles then you cant hear the front or rear pumps at all!. Let it sit over night
and your off again..Cant get any codes..Can a pump over heat and shut both
off??

 

Known symptoms of an acting out relay. Try swapping in a known good, or new fuel pump power relay & let us know how it goes.

 

just put a new one last week (new relay)

 

you can hear the relay click when you try to start but no pump noise front or rear.

 

OK, good feedback on the new fuel pump power relay. Then have a look at the in cabin fuel pump cut off inertia switch, to see if its been kicked & tripped by a size 12 shoe. If not tripped, try thumping it so it'll trip, the little post stop it will pop up, then reset in a new contact position & see how it goes. If still no joy, use your test light, or multimeter on the 20 VDC range, from both sides of the inertia switch to a good ground, to see if B+ is getting from the power relay to & through the inertia switch for a couple of seconds when you turn the ignition to KOEO, before cranking the engine & let us know what you find.

 

does the inertia switch throw a code when it is set off?

 

I don't know, but doubt that OBD-1 was that sophisticated. Are you getting a CEL indicating a code now????

 

no new codes, just thinking about bypassing it with jumper wire.

 

Goggle EEC-4 test connector. You want a picture of the connector that shows the location of the "fuel pump pin"

With the key turned to run take a scrap piece of wire & connect that pin to the negative battery post & the pumps will run.

Do this now and do it again when it wont start.

 

Turns out that i wont have access to a computer for the rest of the day.

When the truck is in no start mode see if you hear the pump relay click when you ground the fuel pump pin.

If it clicks but the pumps dont run, leave your ground wire connected & check for 12 volts at the inertia switch.

The pump relay is under the hood next to the air filter box.

 

thanks 87 xlt ,a pic would be nice..the truck started right up this am.for now I jumped the inertia switch and will have to take it out for a ride..also thank you pawpaw..i will let you know how it goes...

 

OK, just be careful & don't have an accident, because the inertia switch is disabled & won't turn the fuel pump off, so it'll continue to run & feed a fire!!!!
Take your multimeter, or 12 volt test light along, so if it stops running you can test for 12 volts to & through the inertia switch.
If no voltage to the inertia switch occurs, check the wiring back to the fuel pump power relay power distribution box fuel pump relay Contacts. Members have reported finding corrosion at the power relay female contacts, causing intermittent woes.
If you find you have 12 volts to & through the inertia switch, wiggle the wiring run from the inertia switch all the way to the fuel pump electrical connector. You can rig a length of stiff rubber hose to reach its connector atop the fuel tank from the drivers side. If no wiggle test joy, try thumping the pump with the hose, or thump the fuel tank smartly with the heal of your fist, to see if you can wake the pump up.
Let us know what you find.

 

Thank you ALL..Too it out today nd it ran great!! All I have found are aftermarket inertia switches.

 

If you've come to believe the inertia switch is faulty, consider trying a salvage yard for a late model donor inertia switch that looks to be in good condition & measure resistance through it with your multimeter before purchase.

 

sounds good pawpaw. thanks..