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Great info
 

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Discussion Starter #23
Ah a oldie but goodie thread :)

If your LP PSI is too high the truck will likely surge at idle.
 

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Can i monitor lift pump psi with an edge insight cts?
 

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Discussion Starter #25
So how can I tell if my lift pump pressure is too high?

You can gauge the pressure and see that say, but you can also use your v2/autocal to see if the actual pressure is jumping higher than the desired pressure.


Many times lift pump pressure being high will cause the truck to "surge" at idle... A faulty FPR can make it do the same thing, however, log the actual and desired pressure and see if actual is significantly higher than desired and then adjust accordingly, if no change, then likely FPR issue!

This thread is a oldie but goodie!
 

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Thanks Kory!
 

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This may be a dumb question, but just for my sanity, am I looking for the fuel rail pressure when trying yo see if my lift pump pressure is too high? Also at idle, my maf is reading 38 g/s . is this fine considering you said normal is 40 g/s?
 

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So i used a scanner today to control fuel rail pressure and the furthest I was able to get it was 160mpa. The scanner wouldnt let me go any higher than this. I'll attach a picture. My truck was able to match the desired rail pressure, obviously the truck sounded like it had almost a lope tune on it haha.

I was on my DSP position 1 tune, which is just a heavy tow. Should I be able to go higher than 23kpsi? Or is that the most that can be commanded.

160mpa is converted to 23206.032 psi btw
 

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I believe that's peak pressure for an lly cp3/regulator
 

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What about a late LML, with heavy 40hp?
 
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