Bronco 2 2.8 Timing issue

B27766 · May 7, 2015

So I picked a Bronco 2 from a friend for free. It is suppose to be a runner with only 30,000 on a rebuilt. I went ahead and did some upgrades knowing this will be my driver to work and back. I did the Duraspark conversion and installed a Holley 350. The issue I'm having is it will only fire for a second then die and pop back through the carb and it will only start once I let off turning it over then it fires. I have checked TDC with the plug out and made sure the rotor is at #1 so its not out 180. Double checked that all the wires are correct and everything so I'm stuck. I had it idling for a split second and ran out and hit the light on the dampener and its not even flashing on the #'s??? So I'm confused everything I did is what I have done on the other 3 Fords I own and never had an issue like this. It acts like its a 180 out but with everything set correctly I don't see how it is? Any help on this would be great or pointers or something I'm missing?? Thanks in advance

RonD · May 7, 2015

Duraspark will have two separate power paths for the Coils power "+" terminal

You are missing the START wire, so coil doesn't get power until key moves to RUN position.

To test this put a jumper wire from battery positive to Coil's "+" terminal, start engine, it should fire right up now.

Look at Post 10 here: http://www.fordmuscleforums.com/all-ford-techboard/510704-duraspark-ii-wiring-question.html

You do need to add a Ballast Resistor to the RUN pathway(Ford used resistor wires but they are 45" to 60" long)
Ballast resistor would mount to the firewall away from any wires, it gets hot, then RUN wire from key switch goes to resistor and then wire from resistor to RED on Duraspark.

White wire on Duraspark goes to "I" post on 4 post starter relay(solenoid), this wire gives the coil power when cranking.

A coil will burn out in a few months if you run 13.5 volts(alternator voltage) to it all the time.
The ballast resistor(or resistor wire) cuts that voltage down to 7-8volts, which prevents coil from burning out.
But when you start a cold engine you want a hotter spark, so you want battery voltage, that why the 2 different power paths.

kimcrwbr1 · May 7, 2015

If you use the stock TFI coil all you need is key on hot to the red wire on the module and coil pos. There is a two wire connector for the module but the colors are backwards when you plug it in that is correct. Red goes to white and white goes to red it is by the master brake cylinder. Do you still have the square TFI coil it does not need ballast just key on hot. Been running mine like this for over four years now without a hitch.

kimcrwbr1 · May 7, 2015

Once you get the spark good disconnect the vacuum advance and plug the hose and set the base timing exactly 10 DBTDC. Connect the vacuum advance and set the idle air needles for the highest possible rpms. The 350 holly is too much carb for the 2.8 you will never get it to perform as you will with a autolite 2150 with the 1.08 venturi. The 2.8 only pulls about 270cfm WOT not enough to process the fuel in the 350 venturi.

B27766 · May 8, 2015

Thanks for the response guys. I'll try the jumper wire tomorrow the weird thing is it ran long enough for me to move it in front of my garage.

Kim

B27766 · May 8, 2015

Kim, I tossed all the old ignition stuff. The only thing I have left is the Carb. Can I run the old carb with the new ignition? I was just going off the write up on the site.

I just read that post thanks Ron I really missed that step . I need to have that red wire spliced into the coil!

Thanks again I'll try it in the morning just got home from work

kimcrwbr1 · May 8, 2015

I still say go to the bone yard and get a square stock TFI coil and be done with it. Key on hot coil pos and green wire from module to coil neg.

B27766 · May 8, 2015

Spliced the wire in and it fired right up! Thanks guys. Are the starters known to be slow and noise? sounds like I might have to replace it. I set the timing right a 10 and took it for a spin runs pretty strong.

RonD · May 8, 2015

Good work

Slow and noisy starter motor is just getting old, don't recall any "known" issues with 2.8l starters vs other Ford engines.
The age of the ring gear, and the thousands of starts over the years may wear starter gear out faster, making noise.
Battery cable to starter motor may be passing lower amps, making for slower motor, clean connections.

B27766 · May 9, 2015

Alright thanks Ron I'll check those next

Bronco 2 2.8 Timing issue

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