Ok so having some ignition issues with the wife's 75. Engine was just rebuilt, pertonix two wire distributor and a flame thrower ignition coil. Driving down the road and it will cut out or die and fire back up. Yesterday it didn't fire back up. Tried to start it a a few times and then didn't have time to look at it. Today I went out and checked power at the coil and then Pulled cap and checked the rotor. Then I pulled number 1 spark plug to check spark. I jumped it off the starter relay and the damn thing fired right up. I didn't do anything to change the no start condition. Any help would be great. Thanks Tim

 

I stay away from Petronix-too many come backs. No come backs with MSD. Just my experience only.

 

That's funny. On other forums they hate MSD because of all the failures!
Well, that's not quite the same probably, as the failures are the ICM's and not the distributors specifically. So maybe you're right.
That said though, I've never had any trouble with Ignitors over the years.

Where is your Red wire getting it's power from elkarcher? What about the coil?
The Ignitors like the full 12v rather than running off of the original resistor wire. The coil might, or might not like 12v though, depending on exactly which part number you bought.

What about the gap between the magnetic pickup and the reluctor/rotor/thingy? Should be .030" if I remember. The Ignitor comes with a feeler gauge to set the gap. If it's slipped over time it can give you erratic running.

It's true what 1976 says, that your Pertronix device might be at fault. But there are other things to check as well.

Good luck.

Paul

 

I've had ignition switches wear out and fail with very similar symptoms. Did you try jiggling the switch when it's dieing?

 

I did mess with the switch when it was dying and no change. The harness is new and so is the switch. All centech Not saying it didnt go bad. I didnt check the gap yet but will. I will double check the power wire

 

The part might need to be warmed up/hot, to exhibit failure symptoms?

 

Yeah, even with Centech switches you can't just assume that new is good anymore.
We've been lucky so far, and I don't remember ever hearing of a Centech-supplied ignition switch going bad prematurely on the Broncos. But they still can...

Did you use a ballast resistor, or just wire the ignition straight to full voltage?
Ignitor Red wire connected to the coil's positive post? Or has it's own source?
Are you still running the radio noise suppressors? One on the coil positive? If so, if one starts to fail it can short to ground and cause ignition stoppage.

Paul

 

Hey Tim. You might want to check that ignition switch. The Centech switch that I wired in when I did mine actually came apart behind the dash not long after I wired it up. Had to pull it to discover the problem. Ended up in two pieces in my hand. Had to call Jim and order another. So far so good.

 

Hah! Bummer... I guess they're not immune either.
Although I have not heard of any directly, we sell a lot of Bronco ignition switches too, so very likely at least some of them have come back over the years. Recently a lot of stuff we get from the auto parts suppliers is just crap. Ford starter relays being probably the number one fail that I read about on the forums.
The original stuff must've been crap too. A couple of years ago a guy drove up from Monterey to one of our build-parties and on his way out of the parking lot, his switch fell into pieces on the tunnel. What crap for only lasting 45 years!

Good luck with yours. Actually a faulty ignition switch would not be a bad thing. At least it's quick to track down, and relatively easy to replace.

Paul

 

No it has its own power. No radio suppressor, I don't think the centech harness has the ballast resistor. Gotta wait to pull the switch til this weekend. Thanks for all the ideas and tips to try. I will let you know when I get it fixed

 

So I checked the ign swi
tch and it's good. I did notice that i have 12v at the coil when the ign switch is on not running, on both the POS and neg side of the coil. I swapped out the coil with on old one I thought was burned up and the truck fired right up. Still get the hesitation so I'm lost. I did install the fitech injection system on it and then this **** starts. It's installed just like the directions say. So I'm at a loss. Any help would be greatly appreciated. Thanks Tim

 

I'm not sure where to start if it does when it's at operating temp. Besides the coil I really don' have a clue.

 

I'm sorry... What? Are you just now casually mentioning in passing that there is an EFI swap involved? So in all this back and forth over three months (granted, it's only 12 posts, but still three months!), you didn't think it was important to mention that you'd just installed a notoriously finicky modern TBI EFI system on an old truck, that just happens to have also been done just before this problem started?
I'm sorry, but that would have been exceedingly helpful to know right up front.

Ok, sorry Tim, but yes I am throwing you under the bus for them moment to vent a little frustration. Why didn't you mention this little tidbit before now? What makes you think it can only be ignition related when you'd just installed a completely new fuel system, on a rebuilt engine and new wiring system, that probably also needs some fine-tuning out of the box?
You said you followed the instructions? Did you do an extensive setup procedure? Lots of people install these "per the instructions" and can't get them to get out of their own way at first. Not until some extensive pre-programming and mechanical setups are performed.
Are you by any chance running the Fuel Command Center in the engine compartment? Or are you running an inline or in-tank pump setup? Running a return line?
What about the intake manifold? Is it a dual plane or open plenum single plane? Some of these don't meter their fuel very well with a fully divided plenum. A small open-plenum spacer, or better yet a bit of grinding on the divider to open thing sup, can really help modern TBI systems.

In your first post (I think it was first) you mentioned that when you jumpered the starter relay it fires right up. That certainly does sound like an ignition switch on the surface, but not once you add a TBI and computer to the mix,

Ok, so that's good news. What did you test?
You found power going in, and power going out at all the right places and the right times then? That's a very good sign.
Where are all the FiTech wires connected? Sounds off the top that it does sound like you have the proper connections, but what about extra grounds?

That's completely normal if the distributor is in just the right position. The trigger is active, grounding the negative side of the coil and causing the voltage to travel in one terminal and out the other. Not sure exactly how it does this with an electronic ignition, but the experts say it's true. I can see how a physical set of points can do it by simply being closed. Apparently most electronic triggers can do the same.

So that's good. What was it doing before? The same, firing up ok, but hesitating on acceleration? Sounds like a FiTech tuning issue now. Not an ignition switch.
Things that can cause a hesitation are improper ignition timing AND improper fuel mixture (usually too lean) from insufficient accelerator pump function sometimes. IN fact, this is very common on EFI swaps. You may need to do more tuning.
Because you have an Ignitor, I'm assuming you are not trying to get the FiTech to control the timing, correct?
What about your PCV valve? How is it connected? And what valve are you using? Is it the one specified for your engine?
And where is your vacuum advance connected to the TBI? Ported, or "timed" vacuum? Or full vacuum? Or do you even have vacuum advance?
What is your timing set to?
What kind of fuel setup? Full return line? In-tank pump, or FCC, or inline, or low-high-accumulator setup?
What about a pic of the under-hood stuff? Maybe we can see something out of whack. Probably not, but at least we get to see more pics of trucks and engines and wiring!

There's a whole crap-ton more stuff to talk about now. Rebuilt engine and new wiring from the ground up and new fuel system, including EFI computer and it can be many things causing a hesitation.
But hey, at least it runs after all that! Some can hardly get theirs to fire up after a full rebuild. Much less an EFI swap.

And again, sorry for the attitude. But hearing all that stuff and realizing that it might not have as much to do with ignitions as with fuel came as quite a shock.
If you had said that somewhere else and I missed it, sorry about that too. But I didn't see it.

Good luck.

Paul

 

Paul, I don' blame you for throwing me under the bus. Well deserved but I honestly thought I mentioned the efi. Looking back I did not. I did set up the efi correctly. I did the initial timing and the truck fired up and ran right out of the box. Running the 390 edelbrock intake with out the command center. Return line to the tank, timing is set to stock. Ported vacuum and no the fitech is not contrlling the timing. She will fire up and run for a little and then get hot and die. Won't fire backup. Seriously thinking the ign control box is over heating. Everything else has tested good. Got one on the way so will what happens after the install. Again I do apologize for not mentioning the fuel system before.

 

Whew@! What a relief. And here I was though, all fired up for a whole new set of parameters and discussionations ahead!
Not to mention all the knowledgeable pronouncements of sure-fire solutions...

Gotta' admit... I was kind of looking forward to it.

Paul