My '86 2.9 4x4 will not start. The fuel pump will not come on. I changed the relay. When I jumped the pump it comes on, but still will not start. The injectors are getting steady power the whole time (no clicking), even when I'm trying to start it. I heard that when connected, the tester light should blink from the injectors when the truck is starting, I don't know. But like I said they're steady power. I'm getting spark. I tried to change my EEC, still no good. The truck turns over and when I get a rag soaked in Gas stick it in the intake, turn it over, it'll run. The inertia switch is closed I dyked it and twisted the two wires together. I have four wires that go into the fuel pump relay. I have 3 wires that are hot. The wire going to the fuel pump is the only one that is not hot. Also, when I turn the key off and take the key out I'm still getting power to the injectors and all the relays. please help, Tony
86 Bronco II
- Thread starter Tony
- Start date
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Seabronc
New member
You shouldn't have 3 hot wires. On of those is the ground for the relay. If you are reading it as hot, that means you are reading the 12V thru the relay coil because the ground is no good and you are not picking the relay
I looked at the relay, and there's a yellow wire that is in either the 1 or 2 pin and it goes to the positive of the coil. I don't know where is should run. by the way, you have no idea how happy I am that you replied.
Maniac, To answer you, it has two pumps, one low pressure in the tank. 1 high pressure underneath- that's it
Besides the pump wire ( orange with blue stripe) and the constant hot (red) where should the other two go? Sorry I'm kinda new at this eletrical stuff, and very frustrated
Maniac, To answer you, it has two pumps, one low pressure in the tank. 1 high pressure underneath- that's it
Fred,
Besides the pump wire ( orange with blue stripe) and the constant hot (red) where should the other two go? Sorry I'm kinda new at this eletrical stuff, and very frustrated
So you checked 2 relays then? The yellow wire is the one thats supposed to be hot. If your relays check out, run a wire from your battery to the yellow wire. Could be either relay, both should have a yellow wire.
Seabronc
New member
I don't have a BII diagram to look at here so you may have to adapt a little, maybe get a chiltons or Haynes. The best book to get is an EVTM for your year truck, (they are often advertised on ebay. However, Ford is fairly consistant between model lines in how they do things so what I'm telling you should be true for your truck but you may have to adapt a little
/emoticons/[email protected] 2x" width="20" height="20" /> .If your engine is EEC controlled, Red comes from the EEC relay contact and then to the fuel pump coil positive which is controlled by the ignition switch. The Yellow comes from the charge power distribution, (via a fusable link probably attached to the battery terminal on the starter relay), and is attached to the fuel pump relay actuated contct, ( the one that moves when the relay is picked). The other contact goes to the fuel pump via the inertia switch, in some trucks this is brown to the inertia switch and then changes color to the fuel pump. The ground side of the relay coil goes to the EEC control, (I'm not sure why they run the ground thru the EEC, but that is the line that controlls picking the relay. As a test to see if the relay to fuel pump circuit, (including the pump), is good, you could disconnect the wire on that pin and ground the negative side of the coil. That should cause the pump to run, (don't leave it that way).
If that works, then either the path to the EEC has a problem,(probably in a connector or broken wire), or the EEC has a problem, since it controlls the grounding of the relay.
Again, I remind you that I am assuming that Ford did it the same way they do the the FSB fuel pump relay control.
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okay, I found the problem with the injectors. There was a ground on the + of the battery. I switched to the negative and now when I jump my pump, the truck will start. What you were saying is right. There is a tan/light green that goes into the EEC. The red will only turn hot when the ignition is turned. And the yellow goes to the started coil. The tan/green is getting faint power. When I ground it, relay clicks. I'll check for a broken wire. If not, Should I replace the EEC? Thanks again for all of your help!!!!
I have a FSB but it sounds as though its very simular, my front drive shaft ate through the wiring harness to the front pump and fried the output on the EEC which supplied power to the yellow wire. I ran a jumper wire straight to the yellow wire and that did the trick. I am currently driving like that now, I have ordered another wiring harness and PCM to correct the problem. If that helps any, great sure sounds like you have the same type of problem.
Seabronc
New member
If you have a good wire all the way to the EEC, then it probably is an EEC problem.
Good luck,
>-I went to a junk yard and grabbed another EEC. That's what the problem is! I appreciate all of your help. I have to do a tune up on it but I think everything will be okay. This truck has been sitting for about 3 years. I was wondering besides oil, plugs, wires, coolant, ***** trans fluid and filter is there anything else I should do to it? And also would bad gas make it have black smoke come out exhaust? Thanks again and hope maybe I'll be able to return the favor! Tony
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