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Dr. Hamman
Dr. Hamman, Ford Technician
Category: Ford
Satisfied Customers: 6286
Experience:  I have 30 years of Ford Technician experience. I have built many custom Fords, I also collect them.
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f350: I have a 1990 f350 7.5 460. My problem is I have only

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I have a 1990 f350 7.5 460. My problem is I have only one intial spark when cranking over motor. Any suggestions?

Hi, I am a professional certified mechanic, with an engineering background, and 35+ years experience. I will do my best to assist you. Also keep in mind I don't know if you are a pro or a novice, so feel free to add any additional info at any time.



The spark problem is probably the ignition module failing, or a bad connection in the ignition system. Those are the most common cause of problems with this TFI type of ignition system. These were not plagued with problems, but they did have a few more problems the older type Ford electronic ignition systems. I do know of a great writeup on going through this system and finding the problem. I will post a link for that HERE. Also Rockauto (A LINK HERE) had a sale on these ignition modules, they might still have some left. I picked up a few of them not too long age, they were selling them for $13.98 + shipping, normally you would pay closer to $50, or even more. Go over all of this and if you have any more questions at all, I am here to help. Good luck with it, have a great day, and Thanks for using Just Answer.


I do not get paid for my work unless you rate at 3 to 5 Smiley Faces or Stars, a bonus is always greatly appreciated. If the answer is not clear, let me know what additional help you need, and I will be happy to assist you further.

 

Customer: replied 4 years ago.
Replaced ignition module already. I get one initial spark while cranking

Hi, I am a professional certified mechanic, with an engineering background, and 35+ years experience. I will do my best to assist you. Also keep in mind I don't know if you are a pro or a novice, so feel free to add any additional info at any time.



Odds are you have a wire broken inside the plastic that covers the wire, or other bad connection. The electrical pickup in the distributor is the second most common failure item. So the pickup that reads the distributors rotation very suspect. Beyond that the coil would be the next most suspect part. Normally a failing coil wont spark once like your system is. So I would look real hard at the pickup in the distributor, and the wiring that connects the parts of the ignition system. I would use the link I left for you and go through the tests, it should allow you to figure out the problem, it can take some time. Go over all of this and if you have any more questions at all, I am here to help. Good luck with it, have a great day, and Thanks for using Just Answer.


I do not get paid for my work unless you rate at 3 to 5 Smiley Faces or Stars, a bonus is always greatly appreciated. If the answer is not clear, let me know what additional help you need, and I will be happy to assist you further.


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