getting frustrated

[equalXlength]

my fuel pumps will only turn on if i jump the yellow wire and the orng/lt blue wire. when i plug the relay in i get nothing, i have tryed two new relays and nothing. please help me

 

[AKBroncoII]

Check the connection. Sounds like your key on wire is not allowing the relay to close.

 

[equalXlength]

do you now which wire is for key on?

 

[Psychopete]

FWIW, The key controls the computer relay, the computer controls the fuel pump relay... Not familiar with the wiring colors, but I do know a little about the circuit.

There's a way to test the fuel pump circuit from the diagnostic plug, but I've never had to try it. I believe it basically supplements the ground from the computer to the fuel pump relay from what I remember. Might be helpful here.

Are you getting any spark?

Pete

 

[equalXlength]

i just purchased this vehicle 1988 bronco II 2.9 4x4 auto. just replaced the fuel pump, eec relay, fuel pump relay, fuel inertia switch. no i dont have spark either.

 

[Psychopete]

i just purchased this vehicle 1988 bronco II 2.9 4x4 auto. just replaced the fuel pump, eec relay, fuel pump relay, fuel inertia switch. no i dont have spark either.

Ugh, I had to walk out side and get my diagram. I have an '88 so wiring colors should match up.

Yellow wire to the relay is 12+v and has a fuse link, orange and light blue is to the fuel pump. Everything there seems good.

Check out if the computer is functioning, like pulling diagnostic codes. There is details in the technical library (EEC-IV diagnostics), you do not need to use an analog volt meter if you have a functioning check engine light. Also make sure the small ground from the battery is connected (computer ground at pin #60) and that you have power (+12v) on pin #1 of the actual computer (larger yellow wire). The computer is under the passenger side kick panel.

Pete

Edit:

Not that pulling codes is helping you at this point, just ANY response from the computer is what you're looking for.

 

[baddis]

with no spark and no fuel i would lean towards a tfi more than a computer issue

 

[equalXlength]

there is 12 volts to the yellow wire going to the computer. does that mean the computer is ok or should i try to pull codes?

 

[equalXlength]

a tfi would mess with the fuel pumps?

 

[baddis]

you can try to pull codes. if it has none remove the tfi and take it to a parts store and have it checked at least 3 times if it tests good. i have had them test good then test bad right after.

 

[equalXlength]

just put a new tfi and nothing has changed. whats next, new computer? I think i need a beer:icon_confused:

 

[Psychopete]

just put a new tfi and nothing has changed. whats next, new computer? I think i need a beer:icon_confused:

It's not that uncommon for the fuse link to blow for the yellow wire to the computer (but you've verified that's OK). I am trying to help you work around in the circuit so that you can determine exactly what is wrong. The fuel pump circuit will not come on unless the computer turns it on (grounding from pin #22), this is why I think the problem lies here. Not the computer itself, more or less that it's missing something.

Have you checked the small ground off the battery? It's been said that the computer won't turn on if this becomes unplugged. Pulling codes will also verify that the computer hasn't lost it's mind.

It's also possible you might not be getting a signal to the computer relay from the ignition when the key is put on run, or the computer relay itself (can you get someone to listen if it's clicking?). The computer relay is directly next to the fuel pump relay. Will get the wiring colors and functions for the ECC relay later on, at work now and do not have my diagram handy.

And if it comes down to it and you find that you want to try another computer, I have a good '88 Ranger computer lying around for auto trans if you needed it. Left over from '90 MAF computer swap.

Pete

 

[equalXlength]

Going back to the yellow wire on the computer. Is that the only wire that should have 12 volts? the small ground from the battery is plugged in. I don't believe the eec relay is clicking when the key is turned on but i will get someone to listen for me. I am borrowing my friends computer scanner tomorrow so that should tell a lot i think. thank you very much for helping me.

 

[UnderMedikated]

I agree with Pschopete,
Check your fuseable link(s).
Computers don't normally go bad on the Ranger/BII's?
You can get a computer at your local salvage yard for little $

 

[UnderMedikated]

Is your ignition switch jacked?

 

[equalXlength]

i will check my fusible links, but i have another question.
green solenoid-fuel pump

 

[holyford86]

well if the eec relay is bad it would cause the fuel pumps to not run, reverse the relays and see if you get the relay to click then.

 

[equalXlength]

green solenoid-fuel pump
brown solenoid-eec
black solenoid-???? and should i have 12 volts here because i dont

 

[Flat Toy]

I have had the following happen to me, Replaced fuel pump relay and truck ran well. The next time I tried it would not start. Found that the wires had come loose inside the the plastic plug and when the relay was installed, instead of slipping over the pins on the relay the pins tried to push them out of the plug. They made contact for awhile then vibration caused them to separate.
When I install a relay now I tack a small punch and push on the wires from the back side of the plug and insure that they push onto the pins of the relay. Might not be the problem but takes only a min. to check and does not cost anything.

 

[equalXlength]

thank you i will try that.