Quote Originally Posted by jderekt View Post
Has taken me a long time to get back to this (truck has been sitting a lot) but I've finally figured out this issue. Turns out the oil pressure sensor, which in 98 was still part of the pump circuit, is slow to bleed off pressure. Which keeps the pump running until the pressure drops to 10psi or so. Which means I've apparently got debris in the sensor.....sensor was replaced when motor was rebuilt. So new sensor going in after I purge that oil passage a bit.
And this circuit is going to be removed to eliminate this completely.

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And here I always thought I had a sticky fuel pressure relay. I'll have to pay attention to if mine lingers longer cold than warm to confirm. I can also watch the oil pressure gauge too I imagine.