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Discussion Starter #1
I am in the process of converting my 1977 ford 302 to a HEI distributor (I broke the original and thought the HEI would be a slam dunk). I thought it might be the voltage drop so I wired directly to the battery. I have 13v with key turned to run and 11v while cranking.

I have checked the spark plugs and I get no spark. I have checked the posts on the cap and get 0v from the post so it is not the plugs or wires. I get the above voltage at the + wire at the distributor.

The distributor is spinning and I have oil pressure.

I am lost as to what to try next. If I can't get this resolved I may go back to stock but would rather not.

All suggestions are more than appreciated
 

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I am in the process of converting my 1977 ford 302 to a HEI distributor (I broke the original and thought the HEI would be a slam dunk). I thought it might be the voltage drop so I wired directly to the battery. I have 13v with key turned to run and 11v while cranking.

I have checked the spark plugs and I get no spark. I have checked the posts on the cap and get 0v from the post so it is not the plugs or wires. I get the above voltage at the + wire at the distributor.

The distributor is spinning and I have oil pressure.

I am lost as to what to try next. If I can't get this resolved I may go back to stock but would rather not.

All suggestions are more than appreciated
What model ford.
Usual problem is ign. control module.
Is this the one with the ign. control module on right fender or on dist.
Most parts places will test the ign module for you.
Says replacing it unless it is bad.
Good luck
 

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Discussion Starter #3
It is a cobra mustang II. With the HEI distributor I have taken the control module out of the process. My understanding is that with the HEI it handles the function of the control module. I ran a direct line from the battery to the distributor.
 

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With HEI you want 12 V while cranking as well as key-on. That is, no ballast resistor like a points type ignition. The HEI should not be continuously connected to the battery. Is the 11 V during cranking due to battery voltage dropping from the starter draw?
 

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Discussion Starter #5
Yes the drop is due to the starter draw. I am not sure on how to keep the draw from happening.

I ran the lead from the battery to a switch then to the distributor. I flip the switch before turning the key. I don't want to burn out the distributor.

Is there a way to keep the voltage from dropping during start up? Anything to boost the voltage without burning up my garage? Or is it time to punt and go back to coil and control module?
 

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Replace module. Could be bad even if new
Your overthinking the voltage drop while cranking.
It's normal. And not the cause for no spark...
 

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HEI has the control module under the distributor rotor under the cap. The modules are not known for their reliability but thankfully they're easy and cheap to replace
 

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Discussion Starter #8
Thanks for all of the info. I finally just gave up on the distributor swap and I am going back to external control module. The purpose of going hei was it going to be a drop and go. Glad to know there are guys with such great knowledge out there.
 

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You can delete the stock Duraspark module and replace with MSD module. I have a MSD 6A on my 76 Cobra II with stock distributor and disconnected the stock module. Follow the Ford wiring diagram in the MSD installation instructions. You will also need the Ford tach adapter to run the stock tachometer.
 

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Which brand HEI is it?

I installed and MSD on my Cleveland, two wires thats all
you don't need any external electronics.
The only thing that makes an HEI desirable is that it has the coil in the cap, cuts down
on wires.
I am a little disappointed in that the MDS HEI for the Cleveland, also fits a 385 block
is it is very tall. It is as high as a 2.5" air cleaner set on the Carb.
 
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