2017 F350 rail pressure drop under WOT

webb06

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Customer dropped this truck off saying it was low on power when towing. He had went out of state the weekend before and on his way home pulled off the highway, fueled up without shutting the truck off and when he got back on the highway he had no power. Ran 55mph all the way home.

I hook up to the truck. No codes. He didn’t clear anything. Doesn’t even have the tuner. Ez single tune. Will build over 26k psi rail pressure when accelerating. Soon as you go WOT rail pressure drops to 4-5000 psi. Really confused why there isn’t a p0087. Never has coded.

I replaced regulator in rail with known good part. No change. I swapped regulator in pump. No change. Low side pressure never drops below 55psi according to IDS. Pulled and inspected inside tank thinking maybe something was restricting flow. Didn’t find anything.

Had the previous owner of the truck come by and reflash tuning since he has the files. Nice of him. No change.

Removed injectors and sent off for testing. Took a fuel sample when removing. Very very little metal flake in sample. Thinking maybe one was returning too much under WOT. All tested okay. So assuming metal flake isn’t hurting anything. Or maybe pump is just starting to fail and something in pump isn’t working correctly?

Now I’m here. Don’t know my next step. Besides swapping the injection pump which could be a waste of $1000. Considered returning to stock but don’t know how well it will even run with exhaust not stock.

Help. Suggestions?


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mostcorey95

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Customer dropped this truck off saying it was low on power when towing. He had went out of state the weekend before and on his way home pulled off the highway, fueled up without shutting the truck off and when he got back on the highway he had no power. Ran 55mph all the way home.

I hook up to the truck. No codes. He didn’t clear anything. Doesn’t even have the tuner. Ez single tune. Will build over 26k psi rail pressure when accelerating. Soon as you go WOT rail pressure drops to 4-5000 psi. Really confused why there isn’t a p0087. Never has coded.

I replaced regulator in rail with known good part. No change. I swapped regulator in pump. No change. Low side pressure never drops below 55psi according to IDS. Pulled and inspected inside tank thinking maybe something was restricting flow. Didn’t find anything.

Had the previous owner of the truck come by and reflash tuning since he has the files. Nice of him. No change.

Removed injectors and sent off for testing. Took a fuel sample when removing. Very very little metal flake in sample. Thinking maybe one was returning too much under WOT. All tested okay. So assuming metal flake isn’t hurting anything. Or maybe pump is just starting to fail and something in pump isn’t working correctly?

Now I’m here. Don’t know my next step. Besides swapping the injection pump which could be a waste of $1000. Considered returning to stock but don’t know how well it will even run with exhaust not stock.

Help. Suggestions?


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Have you checked the metering valve?


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sootie

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stupid question but what is the PCM commanding for icp when it drops to 5ksi
 

webb06

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Installed new injection pump and truck runs as it should. Planning to tear pump apart and see if I can find anything.


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