Electrical problem part 2 - NO SPARK AT PLUG
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Senior User
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From: Fountain
Electrical problem part 2 - NO SPARK AT PLUG
87 f-350 460 Carbed. Had an intermittent no spark problem but now it is continually no spark. So far have checked the grounds, pulled the ecu and had it tested. I also checked and I am getting 12 volts to both sides of the coil. Not sure where to go from here. I hate just throwing parts at it, So I am thinking that it could be the ignition switch, (don't know why I would still get 12 volts at the coil if the ignition switch was bad), the starter selenoid, or the distributor? Any ideas of how these could be checked out without just replacing them? Or can you think of anything else it could be?
pedant
Joined: Jan 2008
Posts: 23,576
Likes: 38
From: EXTREME southwest CT
If you really believe the ignition box is good then my next guess would be the magnetic pickup coil in the distributor. These go bad sometimes and present symptoms similar to yours.
There is a simple color coded schematic available here;
Duraspark II
There is a simple color coded schematic available here;
Duraspark II
Thread Starter
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Senior User
Joined: Mar 2004
Posts: 272
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From: Fountain
If you really believe the ignition box is good then my next guess would be the magnetic pickup coil in the distributor. These go bad sometimes and present symptoms similar to yours.
There is a simple color coded schematic available here;
Duraspark II
There is a simple color coded schematic available here;
Duraspark II
pedant
Joined: Jan 2008
Posts: 23,576
Likes: 38
From: EXTREME southwest CT
I do believe it's possible, yes.
There are a number of threads here that agree with my experience.
Could be a bad wire in the harness too. (one that has been corroding or breaking internally and finally went)
Duraspark_distributor_recurve_instructions_index
This page details the disassembly and reassembly of the DS II distributor well. (in my opinion)
If you test across the leads of the pickup, what resistance reading do you get?
BTW, you should be getting 12v in start, but more like 7 in run to the coil.
You can see there's a resistance wire built into the harness in the aforementioned schematic.
There are a number of threads here that agree with my experience.
Could be a bad wire in the harness too. (one that has been corroding or breaking internally and finally went)
How hard is it to change the magnetic pick up coil in the distributor?
This page details the disassembly and reassembly of the DS II distributor well. (in my opinion)
If you test across the leads of the pickup, what resistance reading do you get?
BTW, you should be getting 12v in start, but more like 7 in run to the coil.
You can see there's a resistance wire built into the harness in the aforementioned schematic.
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