Hmmm, won't start all of the sudden...

[Orangecrush]

Here's a new one. I crank the engine, it begins to start, so I release the key. It instantly dies. At first, I just figured it was an air/fuel thing and kept trying. However, I eventually ealized it's not air/fuel. It's electrical. As soon as I release the key, electricity is cut to the wires and the engine dies.

I figured it was an old ignition switch, so I replaced it. Nope, not that either. So, we're down to:

1) Coil- is there any way a bad coil could cause the symptom I'm describing? On another car, I used to have a switched ground attached to one side of the coil, in order to prevent the car from being started. It would act exactly this way if I forgot to flip the switch back. However, there is no such switch on my Bronco (nothing could be grounding the coil as far as I can tell).

2) Ignition Switch- ruled out as the problem

3) ??

 

[STLKIKN]

If you are losing spark as soon as you release the key from the start position, I would assume a problem with the

positive circuit to the coil. Your truck may have a resistor wire built into that circuit, it may have gone bad.

To test this theory, try a jumper wire from the pos side of the coil to the pos battery post. if the truck starts like normal, you need to track down the break in the wire. (you will need to remove the jumper to shut the truck down...)

Good luck.

 

[Bully Bob]

Use your voltmeter...key in "on" position...see if you have 6-7V at the coil + side.

-----------if NO------------

turn key to start & see if meter jumps to 6-7V

REASON..., You said: "so I replaced it" ....was this new.., used, etc. ..?

& when you say "switch"..I assume you mean the big unit behind the dash with many wires on it.. & you got them all plugged back in, & in the right place.

(Some consider the "switch" to be the front key unit.)

 

[Orangecrush]

If you are losing spark as soon as you release the key from the start position, I would assume a problem with thepositive circuit to the coil. Your truck may have a resistor wire built into that circuit, it may have gone bad.

To test this theory, try a jumper wire from the pos side of the coil to the pos battery post. if the truck starts like normal, you need to track down the break in the wire. (you will need to remove the jumper to shut the truck down...)

Good luck.

Well, that did it. I used a jumper from the battery to the coil and she started right up. Okay, now what? I've tried following the wires from the coil, but I don't really get too far.

There are two wires connected to the hot side of the coil.

* One (red) goes to the resister (not sure if I even need a resister since I believe I don't even have points? I did have the distributor upgraded to a petronix). Anyway, if I bypass the resister by just connecting the wires, it sill shuts of as soon as you release the key. no change.

* The other (red) wire goes into the front of the distributor itslelf. At the same point, a black wire come out of the distributor and back the - side of the coil.

?? Could it just be a bad ignition solenoid or does that ONLY control the flow of power to the starter and has nothing to do with juice getting to the coil??

Thanks.

 

[Bully Bob]

"?? Could it just be a bad ignition solenoid or does that ONLY control the flow of power to the starter and has nothing to do with juice getting to the coil??"

YES

"not sure if I even need a resister since I believe I don't even have points?"

HUH..? @-)

"I did have the distributor upgraded to a petronix"

Oh....., there ya go...

IMHO you need to start with whom ever did this...and/or look at the directions. If it was working.., & now it isn't, no gremlin got in there & switched wires > .....soooooo, some component failed. >

OR--- I'm still suspecious about the dash switch.

"a black wire come out of the distributor and back the - side of the coil."

This is a good thing... /emoticons/[email protected] 2x" width="20" height="20" />

BTW..., that's one nice look'n truck, as I recall.....throw up some more pics......!

 

[Orangecrush]

....well, I guess it's fixed....I re-bypassed the resistor (I thought resistors are only there because point ignitions run on lower voltage; and a full 12v will basically arc weld them?), and it runs like a champ. So, I'm running a full 12, but I think the pertronix is rated for 9-16V. I know only enough about ignition systems to get me in trouble; so, maybe I have this wrong. Anyway, it runs fine now.

And here is a link to the photo album containing photos of OC. http://picasaweb.google.com/RCMMAHON/1969Bronco351W

 

[Bully Bob]

"..Anyway, it runs fine now."

Wah-hooooooo...! ...as "Homer" would say..!

"..but I think the pertronix is rated for 9-16V."

If you talk to Pertronix..,

They req. their coil.., or a "stock" coil. Not doing so may damage the module.

(at least, told to me by a Pertronix rep)

& I believe they req. the 12v to the "plus" side.

The resistor steps down the voltage to the "coil" as it is a 6v coil --(most all stock, older veh., coils are)

12v doesn't weld the points...they just don't last as long.

Some coils are internally resistored.....

If I were you..., I would talk to Pertronix to/and be sure you have the correct combination so-as not to burn up an expensive part....or void warranty.

AND.., I'm jeolous.......(of that truck) ....can I be in your will..?? /

 

[JLasvegas]

glad she is running, man thats a sweet ride

where are those helmets from? what team?

 

[STLKIKN]

Glad to hear shes up and running...

If the in-line resistor has gone bad, you may want to change it out...

or another posibility is that there may be a fusible link in that circuit that has

gone bad. Best to trace that one out to make sure, but like I said, glad shes up and growling for ya!!

 

[Bully Bob]

Hay Orange..., If & when you talk to Pertronics.., (strongly recommend)

Please post the resulting info. ---so that others may benefit.... :-B

Tks.,

B