Fuel pressure troubleshooting, with/without tune

dnsherrill

Registered
A little while back I sent my xcal 2 to a tuner for unlock and custom tune for my 98 LSC, 126k miles, jmodded- no other mods
I noticed under wot it was running poorly with the tune, so someone suggested I evaluate fuel pressure with and without the custom tune
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vid 1: wot with custom tune, notice how it flattens out around 40mph in 1st gear, and again in 2nd gear
https://www.youtube.com/watch?v=1uZ9nzLRkIw
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vid 2: returned to stock tune wot, smooth acceleration but just about 10 seconds 0-60mph
https://www.youtube.com/watch?v=St4MTcvE_ac
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vid 3: replaced fuel filter, revised tune, 1st morning startup with quick wot
https://www.youtube.com/watch?v=5acvjjhiNQI
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vid 4: wot 5 minutes after driving in vid 3, custom tune slightly increased pressure but still low
https://www.youtube.com/watch?v=2kjgyFZVAfw
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vid 5: 10 minutes after driving with custom tune, pressure finally gets normal
https://www.youtube.com/watch?v=39hCbjTOf-4
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at this point I parked, removed vac line from FPR and pressure went to 40 psi, where it stayed until I restarted the car 4 hours later
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at lunch time I returned the tune to stock and checked the pressure again upon startup
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vid 6: returned to stock tune, driving from startup (possible slow pressure increase on startup?)
https://www.youtube.com/watch?v=5SYq-gkNFhY
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so I'm getting different opinions on if the fuel pressure is normal with the stock tune. I replaced the fuel filter and am now wondering about the FPR and/or FP...or possibly the tune is just poorly built? That's actually unlikely, the tuner is well-established and experienced (TruDyno Sports LLC in Conover NC)
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is there anyway of being certain the FPR is good/bad?
 
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