HPFP pressure drop at WOT (with Autotech)

The HPFP pressure holding fine at WOT till 5000rpm and it started dropping flat to 900psi. At the same spot, the AFR run lean. The idle HPFP pressure holding fine at 450psi-ish. No sign of relief valve failure.

I highly suspecting Autotech failures after 50k miles. The WOT log as attached. Appreciate inputs before I spend cash on new internal.

 

Have you physically checked the relief valve at all?

 

You've done the key on warm engine off test? Fuel pressure went up to 1600ish?

 

Yes sir, done KOEO procedure and pressure able to hit 1600psi after about 5 mins.


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Clean the pump, look for scoring inside the collar and on the piston. Also check spill valve for sticky.

 

Thank you @Enki for chipping in. Let me get it done and report back. Appreciated the time to review the log.

 

Updates?

 

I'm waiting for the new autotech internal to arrive. It will takes some time as I stay outside USA. I will do the recommended cleaning and do the log using existing internal. If not working, will take out the hpfp again and put in the new internal. All will be done in single day.


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What happened did It fix the issue @KCi ??? Im with the same issue as you