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Discussion Starter · #1 ·
hi everyone i am having a problem with no start .engine cranks over fine no sound from fuel pumps .checked power to pumps while cranking no power .checked fuse at pass .dash fuse good and power there. tried powering pumps from spare battery and both pumps run on fed power .ran for 30 seconds to pressure system tried again no fire. so then i left spare battery running pumps and tried to start and motor will not crank over ? disconnect spare battery to pumps and motor then will crank no start. dont understand motor not cranking when pumps from another battery. i have been driving this car often and parked for 3 weeks and this problem occurred.i have looked at what was available of wiring diagrams and have trouble placing what is shown to where on car this is . i am going to check relay in trunk to see if its the problem. any help on this would be greatly apricated. thanks john w will watch for responce
 

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The only thing I can think of in a no crank situation with the fuel pump directly powered by a separate power source is that you must be back feeding voltage to the cranking interlock or starter inhibit relay. You'll have to pull up the wiring diagram for your car and see where the power goes and what other components are affected when you power up the fuel pump directly. There may be a diode in that system that is blown allowing that power to back feed something it shouldn't.
 

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Discussion Starter · #5 · (Edited by Moderator)
hi thanks for responding the car turns over with key but will not fire .the fuel pump does not run with key on run ohear them running r start [no voltage in either position] i have fed 12 volts to the fuel pumps and can hear them running clearly . when i turn on key to turn over with the seperate battery hooked up to fuel pumps the car will not turn over at all. this is what i meant to tell you thanks for your help
 

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Discussion Starter · #6 · (Edited by Moderator)
hi Jim thanks for responding i am going to try to study wireing diagrams the ones i have found so far are very hard to read colored backround and enlarging picture to read wire colors distorts to where i cant read but i will go thru again are some easer to read than others? thanks for your help john w
 
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