Here is my issue. Replaced a 1996 7.4/454 block with a new GM 454. Old wiring harness had just one wire coming from oil pressure sender (above engine coupler-Bravo 2) and had a mechanical fuel pump above water pump. New block came with electric fuel pump and has a 3-post fuel pump safety switch where the old oil pressure sender used to be. Old ignition Thunderbolt V, new ignition Delco HEI but it is a Mallory dist.
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On the switch above coupler; one prong is ignition (to purple wire in harness) and I have power going to it. Middle prong is going to starter relay, and third prong is going to fuel pump with a pig-tail to oil pressure sender wire (light blue). I know the fuel pump works as it runs with direct power. The engine turns over, but fuel pump doesn't run.
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When the ignition key/switch is in the on position my oil pressure guage is reading max, when I begin to start the engine,*the oil pressure guage*reads zero so I know something is messed up. The wiring sheets that came with the fuel pump said nothing about the oil pressure sending wire. I know the switch is there to shut the fuel pump down with no engine oil pressure. Any advice or ideas? Should I just go back to the old one wire sender and the mechanical fuel pump?
Thanks, Matt
1996 Bayliner 2858
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On the switch above coupler; one prong is ignition (to purple wire in harness) and I have power going to it. Middle prong is going to starter relay, and third prong is going to fuel pump with a pig-tail to oil pressure sender wire (light blue). I know the fuel pump works as it runs with direct power. The engine turns over, but fuel pump doesn't run.
*
When the ignition key/switch is in the on position my oil pressure guage is reading max, when I begin to start the engine,*the oil pressure guage*reads zero so I know something is messed up. The wiring sheets that came with the fuel pump said nothing about the oil pressure sending wire. I know the switch is there to shut the fuel pump down with no engine oil pressure. Any advice or ideas? Should I just go back to the old one wire sender and the mechanical fuel pump?
Thanks, Matt
1996 Bayliner 2858
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