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Ignition Issues

EarlyElway

Jr. Member
Joined
Dec 11, 2012
Messages
58
Loc.
Shawnee, KS
I swapped out my OEM dizzy and coil last year for a Proform HEI Distrubutror. It hadn't given me problems until last week I couldn't get it to start. All GM jokes aside from you Bronco purists out there what do you think it could be. I have already changed out the coil and the ignition module and it still not firing. The timing did seem to be a little off prior to it quitting but I dropped my timing gun and broke the last time I went to check and kept driving it anyway until I could borrow one from someone.

Is there something else I need to troubleshoot my problem? Any advise would be appreciated.

-Matt
 

Rustytruck

Bronco Guru
Joined
Feb 24, 2002
Messages
10,875
Rent a timing light from the auto parts. Did you use heat sink compound under the module? They don't last very long if you don't use it. Remove No 1 spark plug (Passengers side front) and turn the motor over by hand until you are on the compression stroke then line up your timing marks to top dead center. now pop the cap and see if your rotor is pointing to the No 1 spark plug wire. While the cap is off check the rotor very well it was very common at one time for the spark to burn right through the rotor and short the ignition spark to the distributor shaft. Borrow a spark tester or buy one cheep from Harbor Freight so you can safely test for spark. Other than that you will have to have a volt meter and or a test light to make sure 12 volt power is getting where it needs to be. Another check while the distributor cap is off crank the motor and make sure the rotor is actually turning. there have been some problems with sheering the roll pin holding the distributor gear in place and there have been cases of people stripping the distributor gear teeth if the wrong material is used against the wrong camshafts.

If you resolve the issue please come back and let us know what the problem was.
 

B RON CO

Contributor
Bronco Guru
Joined
Jun 29, 2016
Messages
2,412
Loc.
Statesville, NC
Hi, your HEI needs 12 volts from the key, and your old Ford had about 6 volts through the resistor wire, if you have not changed that. So that 12 volts feeds the power to the input on the HEI. if you have a tach disconnect it for now. Defective tachs cause many ignition problems. GM hei use a ground wire to a coil hold down screw. It is easy to over look the ground screw if your aftermarket distributor has that coil ground. Check that first. Good luck
 

Cortez

Bronco Guru
Joined
Jan 29, 2009
Messages
1,193
What Rusry said...With the distributor cap off double check that the dizzy is turning when it cranks. I just sheared the roll pin on the gear of my dizzy.
 

metal1

Full Member
Joined
May 2, 2016
Messages
259
Loc.
hidesert ,socal
same thing happened to mine a few days after install ended up being the timing chain driven sprocket lost a few plastic teeth
 
OP
OP
E

EarlyElway

Jr. Member
Joined
Dec 11, 2012
Messages
58
Loc.
Shawnee, KS
So I checked the voltage with a voltmeter at the power wire that comes into the dizzy and I'm getting 12V power. I reset everything to TDC and still wouldn't start or fire. I checked the rotor with the cap off and it's turning. I then checked to see if I was getting a spark on the No. 1 plug and I'm not seeing any spark when grounded to the block. Any other thoughts on what it could be?
 
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