Hi all,
My Bronco wouldn't start this morning and I tracked it down to a no-spark issue.

I've been having driving problems with it recently (it'd occasionally surge under acceleration) and then yesterday, it began driving erratically and then died. When I tried to start it, it bucked and backfired. I eventually tracked that down to a sheared pin on the distributor, went and got a new one, fired it back up, and was able to drive around yesterday to work/store/school, etc.

This morning, it fired once, started to run, sputtered, and then died. After that, it cranked and cranked, but wouldn't even begin to try to fire. It had plenty of fuel and air, so I pulled and grounded a spark plug, and then cranked it again. There wasn't even a hint of spark on the spark plug.
First thing I checked was the new distributor, but the shaft was nice and tight, and all the connections were good.

Unfortunately, this distributor isn't kept in stock, so it'll take a few days to get a new one, but it was a A1Cardone with Motorcraft stamped on it, so it looked a like a good, quality unit. I'd also just hate to assume that's it, wait a few days, and then it still doesn't start.

Any ideas on what else it might be? It's about a 15 mile round trip on my bike to work/school, which I can do, but it's really time consuming and it's below freezing out, and I really need my Bronco up and running.

Ideas?

 

Ignition box. Take it out if you can and have it tested. NAPA can probably do the test and have them run the test until it fails.

I had similar problems with my truck early this fall...intermittent dying and failing to start. Had the box tested and sure enough...first time tested it failed. But it passed on the two subsequent tests so it wasn't completely dead yet but was getting there.

 

Good call, I forgot about the ignition box. It's original.

I'll try pulling the one out of my wife's engine this evening and see if it fires up.

 

I would also do an OHMS test on the Diz sender..making sure it was consistent thru your connections to the "box"..and of course the usual fire test at both sides of the coil.

 

Mytruck had a similar no spark issue. the tutorial below helped me get mine going again as I had a bad PIP and once I replaced the distributor, no more problems.

Part 1 -How to Test the Ford Ignition Control Module (Fender Mounted)


We started out replacing the cap and rotor, then the ignition coil. Got the ICM tested and then replaced the pig tail harness on the ICM. Then I was referred to that link and tested the PIP with an LED and it failed the test. Just glad that nightmare was over....


Not sure if the info provided can help, but maybe.

 

The Motorcraft part of the distributor description is OK. but A1 Cardone rebuilds have, shall we say, a somewhat less than stellar reputation? I have bought their rebuilt drive shafts for FWD that were bad out of the box - and which they refused to cover under warranty saying they could find no fault with them.

 

Looks like the coil went kaput. I put the distributor and ignition module in from my wife's Bronco and no difference.

I didn't try the coil because they're different styles, but I did a resistance test on mine.

Primary coil:
Between the + and - post: 0.12 ohms. They say it should be between 0.7 and 1.7.

Secondary coil:
Between the - and center post: 7500 ohms. They say it should be between 7500 and 10500.


The primary test was WAY off, which confirms my suspicions. I'll know for sure when I get another.

 

It might be your meter, take it with you to the parts store and check a new coil.
Is this a square or round coil?

 

It's the round cylinder styled coil.

I did the same test on the coil in my wife's and it checked out correctly.

I just can't use the one in hers because it's the stock style that has the pegs that the wiring harness clamp clips on to (it's converted to a DSII).
Mine used to have that, but now is just the screws with the nuts and the wires have eyelets on them.

 

Look for a coil that has a primary resistance close to 1.2 ohm, to match up with the DS2 module.

The coil failure might be caused by using a aftermarket coil with a lower resistance (~.7) coil.

 

The coil in my wife's Bronco (which is an original DSII) had primary resistance of 0.7. What makes the difference and why would that burn out with the DSII?

 

To work as it was intended by Ford, all the parts have to be a match set.

If the resistance wire is about 1.2 ohms , then the coil primary resistance needs to be some what close to that also, 1.2 ohms, so then the voltage will split evenly across the two components.

If the resistance wire is 1.2 and the coil is .6 = 1.8 total, the split will be 2/3 - 1/3 ... with the coil seeing 4 volts of the 12 volts applied.

If you use a coil with .6 instead of 1.2 the current will double, the heat will double and thus the coil will have to dissipate twice as much heat, or fail trying to dissipate the extra heat. The DS2 module is also exposed to the extra current/heat issue.

In a DS2 IGN system it is best for reliability issues just to use stock matching parts.

Jim