As some of you may know, I've been having quite a few issues with my Bronco. They've gotten worse. Things started out bad and have gotten worse. I replaced the spark plugs, rotor, cap and wires about 2 months ago and it was running good. Then I replaced the gas tank with a used one in like-new condition, and the same for the fuel pump. Thats when things went bad. I have replaced the fuel filter and about a foot of the fuel line with rubber hose as well and I am now having new problems.

This is it was about a week ago...

I turn the key to start the truck, but it would not work on the first try... seemed like it would try to turn over but not catch. When it does finally would start it tried to stall on me, so I'd hit the gas alittle and it will either try and stall again after I let off or it will idle fine. On the road the truck ran fine for a few minutes then it would start to die, I kept pumping the gas pedal all the way to the floor to keep my speed for a short while, then the truck would start slowing down no matter how fast I pump the gas.

Situation as of this past weekend...
I jacked up the rear end so that I could try and listen for the gas pump running, went to start the truck and got the same thing, it tried to turn over and nothing happened. Tried again, and again got the same results. I tried to start it one more time, and everything inside the truck shut off completely. No radio, no lights, no gauges, nothing. I took a voltage meter to the battery and it read 12.5v, then I took it to the cables directly after the terminals and got 5.0v. I banged on the starter a bit, and still had no power inside the truck at all.
After sitting for a day I went back and tried the key in the accessory position, and all the electronics worked fine. Hooked up the voltage testor to see that the battery read 12.5v and the wires after the terminal read 12.5v as well. I tried to start the engine, and once again, everything was gone, no power to anything. I checked my voltages again and got 12.5v for the battery, and 5.0v at the wires right after the terminals... again. Only thing is this time the voltage started to climb quickly up to 12.5v. When it reached 12.5v I opened up the cab and had nothing working inside. Even though I was reading 12.5v at the battery and cable, I had no lights, gauges or anything else.
I don't know what else to do. I tried jumpstarting it the next day and the same thing happened, so I'm completely lost. Anybody have any ideas as to what I'm dealing with here?

 

Bad battery terminals or cables, definately, based on your check:

"I took a voltage meter to the battery and it read 12.5v, then I took it to the cables directly after the terminals and got 5.0v."

Would that also explain the fuel starvation? Maybe, if there's not enough power at the fuel pump.

 

Well for one you NEED to replace the fuel pump with a new one for the application of the vehicle. Hook up a headlight bulb to the power at the fuel pump and then also ground the headlight bulb through the fuel pump ground, turn the key on and does it light. That would tell ya if there is a voltage supply to the pump. As far as all you electrical concerns check the grounds on the engine and inside the truck, maybe a ignition switch concern.

 

Man, I thought this thread was about Nikola Tesla. Now thats an unsolved Electrical Issue.

(I truly thought thats what this thread was. BTW, Nikola Tesla is a good googled read if you dont know about him)

 

I had the same thing happen on My cadillac. Here is a tip. Take a set of Jumper cables and go from the Positive terminal on the battery to the location on the solenoid that the cable connects to. Try starting the truck. If It is the positive cable the Jumpers will act as a battery cable that is bad then it should start normally. If it starts normally it is your positive battery cable. Replace the cable and you should be fine. You can do the same thing for the negative also.

That sounds like you problem to me.

Good luck!

~HJ

 

John, when you had the problem with the Cadillac, did you lose all the power inside the car as well? I don’t quite understand how the solenoid would cut power to the inside of the truck.

 

i had something similar happen to me on my Cuda last summer, check all the grounds for the iginition and also check the relays(i had a few bad ones) and make sure the fuel pump is the right one for the truck cause that would explain the issue with keeping it running. and now that i think about it i did lose all the power inside that cab also.

 

Yep! It was wierd! I would try and turn it over and nothing, then boom the lights would go out and the radio. nothing! I would wait about 15 minutes and they came back on. I had to get it towed home because I was in the cities with it so it really sucked. I called my mechanic and he told me to try that for the cables and it started right up! I replaced the cable and have had no problem since.

~HJ

 

Okay, we may be talking about 2 problems here. First, I agree wholeheartedly with completely replacing the ends of the cables that go to the battery. You have corrosion in them that creates and insulating barrier when damp or whatever and it's blocking current.

Next, the real test of a fuel pump is proper pressure for your application. Generally, fuel injected vehicles use fairly high pressures, and the regulator is in the engine compartment in most older vehicles like that. They are "return" style regulators mostly -- meaning the bypass "excess" fuel back to the tank to keep the pressure constant.

If you used a tank from a carbeurated model, you would not have adequate pressure. Carbeurator type pumps are high volume, low pressure types as a rule. They are designed to keep the float chamber filled, not to produce enough pressure to atomize fuel spraying from an injector.

Also, if you want to hear the pump, don't bother to jack up the vehicle. Just take the gas cap off and listen at the fill tube. You can hear it very loudly there.

 

Well, I’m hoping that I’m only dealing with one problem John… that would make my life a hell of a lot easier. So we know then that it is going to be two problems

Thanks for the info on the filler tube, I’ll check that out if I can get the truck running again. And the gas tank is from a fuel injected Bronco, we made sure of that (the second time).

Since it seems to be the popular theory, I will pick up some new wires next time I can get out to the store, thanks for the info all.

 

I forget what engine the bronco had that the tank came out of ? Was it a 302 or 351 ? Would that matter ? I know it was EFI but I forget which one.

I am still thinking the alternator or battery is part of the prob.
the battery died from trying to start it up, you let it sit over night and it comes back up.

I would put the battery on the charger over night and get a fresh start with a good battery. You might be getting 12 volts at the battery but there is no stored current. Even i if you try to jump it if its really really dead its not going to start.

When I tried to start my tempo after it had been sitting for a year or so the battery was so dead I tried to jump it and it would do the same thing. It would turn over but would not catch. I would keep trying but eventually it would lose all power just like that. I left it on the charger over night and it would do the same thing. I finally left it on the charger all day and over night and tried it the next morning. Before it finally worked.

If the battery is dead and you jump the starter to see if the cables are good its not going to work.

I would pull the battery and take it somewhere and have it tested. Even if its new you can get a bad battery.

 

That is true Ben, but I doubt it is the battery because when I tried to start it yesterday, the voltage was 12.5v accross everything in the beginning, after I turned the key, it was 12.5v at the battery and 5.0v at the cables. Then it went right back up to 12.5v within 30 seconds. Even with the fresh 12.5v in the cables, I still wasn't getting anything anywhere else as far as voltage.

 

have you tried taking the cables off and cleaning them. also what is the battery voltage when you are tring to start the truck.

Chad

 

I have replaced the terminals, and cleaned the wires that connect to them. I haven't touched the other ends yet. The voltage on the battery is a constant 12.5v.

 

I would check the other end of the cables and make sure you are getting a good ground and a good connection at the starter. But more then likely I think you have a bad ground.

Chad

 

So if I do indeed have a bad connection somewhere, would that cause the truck to run the way it did?

 

If you dont have enough voltage to properly supply the engine and electronics while is running it will run poor and stall out etc.

Your battery ground is the most important part of a good system..as everything runs through it. I would definetly check the contact surfaces on both ends for a good connection. Most vehicals have a second wire from the neg battery terminal that grounds to the chassis. If you dont have one..it would'nt hurt to add one. I found that the gold plated battery terminals have a great connection ($14.00 @ Autozone) I was sold on them terminals when it eliminated my headlight dimming problems from a high powered stereo.

By the symptoms you explained....I dont think its a alt or battery problem. Sounds more like connections or bad wires.

 

-------------UPDATE----------------

I took a jumper cable from the positive on the battery to the solenoid for the starter. It sent the voltage reading right back down to 0v. What does this mean? is it that the wire is grounding out and needs to be replaced? Or does it mean I have a short somewhere else?

 

That would be most likely EXCEPT that right on the terminals AT the battery he lost like 7 volts! That is ENTIRELY due to corrosion inside the terminals that wrap around the posts.

Taking them out and cleaning them is good, but on some terminals where the wire is crimped inside the terminal, they deteriorate INSIDE the crimp.

I still say: REPLACE the terminals completely. They're cheap. You can get entire cable assemblies if you want. Even if you use the "clamp" type for now (inferior), it'll still be WAY better than your current setup.

Whicever way you go, cut the wires back a little before you strip to expose fresh, undamaged wire.

 

John your right I wasn't thinking about the corrosion inside the terminals.

Chad

 

No problem, Chad -- I just wanted to clarify the "little facts" which sometimes get lost in a discussion like this.

I talked to John last night on the phone. He IS using new terminals, but he didn't cut the wire back so he's still connecting through surface oxidation on the wires. It's amazing how much difference that can make on low voltage circuits like these. He's going to try replacing either the whole lead going to the solenoid, or cutting the wire back, restripping, and using it again (if it's long enough).

 

somehting else I was thinking of (a quick test for it) Removing the wire off of the solenoid and connecting the jumper cable directly to it. This should tell me if its that wire that is the definite problem or not.

 

---------------------UPDATE #2-----------------------

I tested the solenoid yesterday by running a jumper from the solenoid to the positive on the battery (with the solenoid wire still connected), and it dropped the voltage on the wires to 0v, while the battery stayed at 12.5v. I went out today to do the same test, but found that the battery was completely drained overnight. I removed the wire that ran to the solenoid and then hooked up another battery. I then ran a jumper to the solenoid and when I connected it to the positive on the battery, I got a big spark and voltage dropped back down to 0v on the wires. When I removed the jumper, the power went back up to 12.5v in the cables, and the power was immediately restored inside the cab.

What this tells me is that I am not dealing with bad cables, I think it is a problem with the solenoid. Any suggestions?

 

GEt a new solenoid! They are really cheap and easy on those old Ferds! Have you tried using a screwdiver acoss the terminals while somone cranks the truck? It'll spark like a b**** but if everything works fine it is the solenoid!

~HJ

 

Can you explain a bit more John, you lost me there.