87 Bronco

[Rob&teresa]

I have an 87 FS Bronco with a 302 AOD, it died the other day, wouldn't pump gas, neither pump ran, (didn't realize at the time it had two) I replaced the high pressure pump on the frame rail and the filter, still wouldn't start, then realized, by looking through Haynes manual it had two. I dropped the tank and tested the pump, it works, changed the plug, had a bad connector, and finally with the help of the forums here and the book traced out the relay. I replaced that but it still wont run. The relay clicks but the pumps don't run. I used a jumper to get the high pressure to run. Does the low pressure pump run through a different relay? I am not sure that one works even with the jumper. I haven't been brave enough to drive it with the jumper wire, but it ran and idled fine in the driveway for at least 10 mins. I also checked the inertia switch, that's not tripped. I don't have a volt meter at the moment so I can't check the codes.

Bought a multimeter and finally got codes, I have 23 & 24, 23 is for the MAP sensor, and 24 is for the ACT/AIT, my question here is would either one prevent the fuel pump from kicking in?

I tried getting these codes when the engine was warm but couldn't get anything (could be my fault) but when I tried again after letting it set for awhile, then the codes worked. (Or atleast I had it set up right)

 

[BroncoJoe19]

I never worked on one, so I don't have that long term memory that comes with hands on experience, but I am pretty certain that I read that there are two relays... one for each pump. I'm less certain that there are two fuses, one each, but that would make sense too.

EDIT: With a quick look through my Haynes wiring diagram, it does not include (or I missed it) a second relay (but I also didn't see the intank pump) in the diagram.

I am not so sure about two relays, anymore, and think that I may confused an older two pump system with a two tank system. When one has two tanks with a high pressure pump in each tank, I am more certain that each has its own relay.

 

Sorry for not being any help. /emoticons/[email protected] 2x" width="20" height="20" />

I don't think those codes would affect the fuel pump.

 

[Seabronc]

I have an 87 FS Bronco with a 302 AOD, it died the other day, wouldn't pump gas, neither pump ran, (didn't realize at the time it had two) I replaced the high pressure pump on the frame rail and the filter, still wouldn't start, then realized, by looking through Haynes manual it had two. I dropped the tank and tested the pump, it works, changed the plug, had a bad connector, and finally with the help of the forums here and the book traced out the relay. I replaced that but it still wont run. The relay clicks but the pumps don't run. I used a jumper to get the high pressure to run. Does the low pressure pump run through a different relay? I am not sure that one works even with the jumper. I haven't been brave enough to drive it with the jumper wire, but it ran and idled fine in the driveway for at least 10 mins. I also checked the inertia switch, that's not tripped. I don't have a volt meter at the moment so I can't check the codes.
Bought a multimeter and finally got codes, I have 23 & 24, 23 is for the MAP sensor, and 24 is for the ACT/AIT, my question here is would either one prevent the fuel pump from kicking in?

I tried getting these codes when the engine was warm but couldn't get anything (could be my fault) but when I tried again after letting it set for awhile, then the codes worked. (Or atleast I had it set up right)

There is only 1 relay. If you can get them running with a jumper, then you will definitely benefit from using a meter to trace it back. Odds are that either the relay, inertia switch, or a connection is bad. Check the input and output of each til you have it narrowed down to the component, it will save you a lot of money.

Good luck,

>-

 

[Rob&teresa]

Thank you both, been working on it since last sat. and think I will take the day to think, have just been plugging away and spending money and still haven't got it sorted. Thanks again for all the info. I searched both of your posts for days and they were a big help.

One more thought that I had, is there a fusible link for the pump? The relay does activate, ( it clicks when I turn on the switch) but the pump doesn't kick in. Also is it set up so if one doesn't work the other doesn't?

 

[miesk5]

yo!

Here is a 1987 Ford Bronco Fuel Pump Wiring Diagram (2 pumps) by Vincent C

& one by Ryan his URl lists it for an 86, diagram shows both in-line & in-tank pumps.

 

[Rob&teresa]

As near as I can tell, after asking a friend that was a ford mechanic it's the relay, the store gave me one that had 5 plugs, mine has 4, and assured me it would work. I took it back in and another fellow at the parts store took the time to look up in the and find one that matches mine. I will have it Tuesday and see if that works. Thank you all for the help, and by the way, does anyone know where I can a three wire pigtail for the sending unit ?

 

[miesk5]

As near as I can tell, after asking a friend that was a ford mechanic it's the relay, the store gave me one that had 5 plugs, mine has 4, and assured me it would work. I took it back in and another fellow at the parts store took the time to look up in the and find one that matches mine. I will have it Tuesday and see if that works. Thank you all for the help, and by the way, does anyone know where I can a three wire pigtail for the sending unit ?

Figures..huh?..read my caption under my "pic"...

RockAuto has em as well as PICO...Call NAPA for da pigtail or ask any parts store other than daZ to get one

Sixlitre got one.. should be same[/url]

and his overall tank, wiring etc job here

 

[Rob&teresa]

So here's the latest, if anyone is still watching this one, I fixed the tank plug, (replaced ground, wasn't enough room with three separate plugs), found the wire running to the back (in tank) pump was in three pieces (from the tank to the transfer case) pulled it the rest of the out to the engine compartment, couldn't get into the section in the big rubber holder. Does it go to the relay (different colored wire) or to the ignition? As near as I can tell from the Haynes manual it goes to the EEC.

Ran new wire to the tank,tried it with the original connected to the new,nothing, checked the pump relay ( did something wrong cause got nothing, even tried it on a brand new one never in the truck, tried to follow BroncoJoe's explanation). Still with all the wires hooked up it wont run the pumps, so as a quick fix I put the hot wire into the hot side of the relay. It runs both pumps, need to get it back on the road and return the loaner I have now.

So any ideas? :wacko:

 

[Justshootme84]

I just spent the past 3 weeks fixin the in-tank fuel pump on my 98 Z-71 (see post in Local tavern), and removed the fuel pump from the 88 F-350 to pump out the old gas. i had a similar problem, the relay worked but the pump did not. I'll take a look at the wiring diagrams later tonight, but what I did was check for 12v at the pump plug/ connector. Since I had power at the plug, the pump was bad. But for awhile there, i was checking the wrong wire and got nothing, or 5v (in-tank pressure sensor). So for now, my question is this:

Do you have 12v power at the in-tank pump plug and frame-mounted pump when the relay kicks on? JSM84