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Old 08-07-2015, 10:55 PM
Frank Reiner Frank Reiner is offline
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Join Date: Feb 2011
Location: Modesto CA
Posts: 4,400
Quote:
Originally Posted by pmckechnie View Post
Rich, Have you checked for spark at the plugs? The reason I ask is that the fuel pump will not start until it has a tach signal from the ign control system. That will also explain why it won't run with the fuel pump power jumpered.

PaulM
Roller:

There are two triggers that will close the fuel pump relay: 1) the cranking signal that is supplied when the key is turned to "Start", and 2) as cited by pmc, a signal from the ignition after engine start.

When you are cranking the engine the pumps are running on the "Start" signal, and enough fuel is supplied to partially fire the engine.

On the subject of pumps, consider the possibility that only one of the pumps is operating; the symptoms you describe are consistent with low fuel pressure. Try the jumper again with one, and then the other pump ground wire disconnected.
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