No spark!!
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No spark!!
I have a 79 ford 460. It has a jacobs coil, mallory ready to run distributor, all factory ford ignition has been taken out. I recently installed a FAST fuel injection system on it. After installing the system, the truck ran fine for a day. I shut it off after a ten mile drive, and it wont start. No spark! I have 12 volts to pos side of coil and 12 volts on neg side, but it does not pulsate when cranking. I replaced the distributor and the coil, and that didnt help. I have power to the distributor and back to the coil. Just wondering if anyone has any sugestions to look at or has had the same problem. Any help would be greatly appriciated. Thanks!
Postmaster
Joined: Dec 2008
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From: Southern Oregon Coast
What does it have for an ignition module? What's controlling the spark?
MSEE
Joined: Apr 2004
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From: Austin, TX
Dean, how do you have your system wired? Please describe what is connected to what.
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You have to run a resistor just like a factory Ford to bring the voltage down for a Mallory Unilite distributor.
I am extremely biased negatively on Mallory crap. I ran a Mallory distributor for 10 years and hated just about every moment of it.
Josh
I am extremely biased negatively on Mallory crap. I ran a Mallory distributor for 10 years and hated just about every moment of it.
Josh
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Ok ill try to explain how i have the system wired in. I have 12 volts keyed power running to the pos side of coil, then 12 volts going to distributor. Then there is 12 volts going back from the distributor to the neg side of the coil (pulsating for spark). The coil is grounded to neg side of battery along with the distributor also. The battery is grounded to the block. The wire going from the dis to the neg side of the coil should pulse when cranking but it doesnt. The fuel injection system is wired as followed: Power to battery pos and neg. 12 volt keyed power to the computer. The RPM tach module is wired to neg side of battery for ground and neg side of coil for rpm readings. The fuel system seems to be working as it should be i am just not getting any spark. I changed distributors and coils and that didnt help any. The signal going back to the neg coil side is not pulsating. I am confused haha. I have no resistor wired in for the distributor. The second one i tried was an MSD 8350 ready to run which does not need a resistor and it had no change. Any help would be awesome! Thanks!!
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The module in the distrubutor (or points or the Duraspark pick-up) is what grounds the coil.
Josh
MSEE
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From: Austin, TX
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Thanks guys. I think the coil is grounded through the RPM tach module for the fuel injection which is then grounded to the battery negative terminal. The RPM module is grounded to the neg side of battery and the neg side of coil is hooked into this wire. Maybe this is causing my problem. What i dont get is that the truck was running good, i shut it off, then went to start again and no start no spark. I never changed any wiring in that time. I will try that tho when i go home from work to not ground the coil (if it is) to the neg side and see if that helps. Thanks guys for the help!!
Dean Williams
Dean Williams
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