1997 7.3 Fluctuating Fuel Pressure - PowerStrokeNation : Ford Powerstroke Diesel Forum
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post #1 of 2 (permalink) Old 04-17-2018, 06:19 PM Thread Starter
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1997 7.3 Fluctuating Fuel Pressure

Does anyone know if fluctuating fuel pressure is normal for the obs 7.3?

I have an electric fuel pressure gauge installed on the fuel bowl, and at idle it jumps randomly between 50 and 70 psi (I have the FPR shimmed to 70psi) and under WOT the pressure drops off to about 35 psi.

I've read that the pressure shouldn't be steady due to the mechanical fuel pump, but this seems like a lot of variation to me. At idle my truck shakes considerably, and seems to be lacking power.

I've changed the fuel filter and pulled the fuel tanks to check if the in-tank screens were plugged, but there are no screens. Hoping someone has some advice. Thanks.
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post #2 of 2 (permalink) Old 04-17-2018, 06:52 PM
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Re: 1997 7.3 Fluctuating Fuel Pressure

If no shower heads are present then how are hoses positioned for fuel pickup? Are hoses collapsing, restricting fuel out of tank?

I had this in an older IDI that someone had fixed without shower heads. I redid with E5TZ-9J306-BA and it worked fine afterwards.

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