I have a 1990 f150 5.0 that I am helping a friend work on.. The tach jumps like you are killing the ignition. I changed the distributor out and it ran great for about 30 minutes and went back to doing the same thing so I got another distributor and was fixing to swap it out and decided to put a noid light inline with the coil wire fired it up and it ran great. I thought it could be something to do with the coil wire so I put another wire on it and tach still jumped and engine would shut off with tach jump but it stays running. Also had a test light going to the power wires going to coil and it is flickering like the tach is. I tried another coil also.It is acting like it is losing voltage intermittently.I have ran a wire from batt to coil hot and still does it. Just wondering if anyone has ran across something like this
Thanks Mitch

 

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Go to Ch.5 and follow the ignition system troubleshooting guide (usually Sec.5 or 7).

 

Thanks I will see what I can find

 

is their a simple way to find that info or do I have to go thru each page to find it
thanks

 

I installed another new distributor and so far it is running like it should. Have not ran it but about 20 mins. Will drive it more tomorrow.
Thanks Mitch

 

Well, there's a table of contents at the front of the book, and at the beginning of each chapter; and there's an index in the back; and there's CTRL+F on a computer.

 

Thanks for the response