[rivee]

I have a 1982 full size California smogged Bronco.

It has a 302ci California motor with PS and AC

I've owned it for 2 years.

It turns over but won't start because their is no spark to the plugs.

I have sent it to two mechanics and both times they say it's fixed and then within a couple of weeks it's back to the same thing. It starts when it wants to. But now it won't start at all. I think that when the mechanics have it they fool aroung with it and then it starts, like it does to me sometimes so they think it's fixed.

I have dumped tons of $$ into this POS and am too embarassed to say how much.

I bought this for my daughter for when she gets home from school but am considering watching it roll off of a very tall mountain instead.

So far this is what I've replaced or repaired just this year:

1. New Napa rebuilt 302 5.0L motor
2. New Holly carb.
3. New ignition module (Dura spark) (replaced twice this year)
4. New cap, rotor, wires, plugs
5. New battery
6. New ignition switch
7. New relay for the carb stepper motor
8. New tie rods, drag link, tires, paint job ect.
9. New exhaust system
10. New distributor

So now I still have this starting problem. I've checked the voltage at the +coil when ignition is "on" and it reads only 4.6 volts. I've also checked the -coil and it is grounded.

The motor turns over great but won't fire. Something I noticed but not sure if it is significant is that when I try and start it then turn the key to "off", it jumps like it wants to start when I get to the "off" position. I've checked and rechecked the new ign. switch and it checks out fine and also it's the same thing that happened before installing the new switch.

I've traced the wire from the +coil back to the ignition switch and get 2.2ohms of resistance. Is this normal? Is this a resistance wire?

Any and all help would be deeply appreciated.

John

 

[jermil01]

1. New Napa rebuilt 302 5.0L motor
2. New Holly carb.
3. New ignition module (Dura spark) (replaced twice this year)
4. New cap, rotor, wires, plugs
5. New battery
6. New ignition switch
7. New relay for the carb stepper motor
8. New tie rods, drag link, tires, paint job ect.
9. New exhaust system
10. New distributor

You replaced all of this, what about the coil I know you said it is grounded but that does not necessarily mean its working?

 

[Davids78Bronco]

You've pretty much just found your problem... the coil. Besides, you've replaced nearly everything else under the hood, the coil's the last thing left

 

[Davids78Bronco]

haha, is this where I call jinx? Actually, reading that, the coil and ignition module were my first guesses... seeing as how you've replace the ig mod twice, and not the coil, well... you know where you're going next, don't you?

 

[jerry 1 a b]

It sounds to me like you need to jack up the radiator cap and drive a new truck under it.

So the coil is good when it's cold, but that doesn't mean it isn't a bad coil. Most people would say that a coil is either good or bad, and there is no gray area, but that's not true (IMO). Most coils are just a copper wire wound up real tight. If you get an open anywhere in the wire, it will start to act funny. Because metal expands when it's hot, and contracts when it's cold, you can have a larger opening when hot than cold. Then of course after a while, it will go all the way. It seems like it's shot now. I hate to tell you another part to replace, but that's what I would look at.

As far as the power source, well here are the stats for Dura Spark II right out of my Haynes manual:

Coil primary.............................. 0.8 to 1.6 ohms
Coil secondary.......................... 7,700 to 10,500 ohms
Ballast resistor.......................... 0.8 to 1.6 ohms
Stator assembly and harness... 400 to 1,300 ohms
Stator assembly........................ 400 to 1,000 ohms

If you are unsure of power source to the coil, then check source to the ignition module, and then keep tracing it back. No one said the parts you put on where going to be good, so you may have purchased some bad parts.


I drew some pictures for ya to help as a guide. I hope you can see it. If not, it's in the Haynes manual.

To test this way, you stick a needle in the wire, and then clip your test leads to the wire.

 

[jermil01]

haha, is this where I call jinx? Actually, reading that, the coil and ignition module were my first guesses... seeing as how you've replace the ig mod twice, and not the coil, well... you know where you're going next, don't you?

Its either a jinx, or a goocher, I don't know what you call it. But your post was right there after I mine went up.

rivee, sounds to me like jerry 1 a b, knows a lot more about the whole electrical thing then I do. But like Dave and I said, coil...anyway, good luck and keep us updated.

 

[rivee]

Jerry, you are right on with the "jacking up the rad. cap and driving a new truck under it".

If I didn't have so much $$ into it I'd probably enjoy watching it "accidently roll down my driveway and over the embankment (230').

I changed coils a while back with a generic one and it didn't make a difference so I switched them back. I don't know for sure that the generic coil was good, but since it didn't start then either I figured that it wasn't it.

Why am I only getting 4.6 volts to the +coil?

Shouldn't it be at least 5.5v or so?

If so then I can't see it being the coil.

Jerry are the resistence measurements you quoted in relation with ground?

BTW Jerry, thanks for the diagrams, really appreciate it.

And thanks to you all for your imput.

Now I get to to take all this info back to the garage and @#$% with it some more....................just maybe it will.......................work

 

[jerry 1 a b]

Ok, I have a better example for measuring supply voltage. Use the distributor base as a ground. Turn the key to the RUN (not start) position, and then hook your positive lead to the Red wire from the coil. Between 6 to 8 volts is ok. If it's less then check the ballast resistor.

To inspect the resistor, you have to isolate it, so disconnect the connector (red and white) from the ignition module. Now, stick your leads in the connectors (both) on the Red wire side. (use the picture I drew as a reference) It doesn't matter which lead goes where. (you're just putting juice from the meter's battery through it +/-) It should read between 0.8 and 1.6 ohms. If it's out of tolerance, then the resistor is the problem.

 

[Dovepower]

Inspect your wires very well for damage. It's possible you have a partially broken wire. Sometimes the connections loosen up and don't make contact all the time. Check the wiring for your entire ignition system including the ignition module. This was my problem at one point and since you have changed everything else it might be yours.

 

[pc12driver]

I'm having the exact same problem with my 1982 5.0 2 Bbl carb. engine. It jumps when going back to off position. I've replaced just about everything you listed also. What was the problem ?

 

[pc12driver]

I can almost put money on it that it's the pickup coil in the distributor. I just discovered mine was bad......EXACT same symptoms now resolved.

 

[socal82bronco]

did you ever get it running? Im having the same problem with the no start.