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No start no spark no injection pulses no fuel pressure. No two second prime. Can take a test light to battery positive and touch fuel pump control wire and fuel pump runs. All coils and injectors have 12 volts. No control. Had some rodent wire damage. Have battery voltage on wire from ignition switch to the pcm during run and crank position. All pcm powers and grounds are good. 5 volt ref good. What inputs is the pcm looking at to turn on the fuel pump relay for two seconds to prime the rail? I was thinking of the one wire that goes from ignition switch to the pcm. Anyone have any idea. Thanks in advance. Also did a crank sensor bypass test test light connected to battery positive and no response.
hi guys depending on what you got believe you do need a crank signal (for fuel pump prime also)at computer if its a Chrysler or ford system I believe during cranking ecm is in charge and during run the icm will be in charge any moderators please set me right with this if I am wrong thanks !!!!!
Last edit: 7 years 1 month ago by chief eaglebear.
There is a I believe orange wire from ignition switch to pcm that has battery voltage in run and crank position. How would the pcm know that the ignition was in the ON position to energize the fuel pump relay for two seconds to prime the rail. Also pcm needs to know when to energize pcm relay that provides battery voltage to injectors and coils.
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