How much Pump with e85 and turbo?
It's a gummed up/faulty regulator, plain and simple. You should be able to support your HP level with just one of those pumps where the pressure drops. You don't need giant fuel lines, aftermarket filter, none of that stuff. The fact that the regulator went down to 45psi with vacuum and didn't come back up to 58 after you removed it proves it's the regulator. Smack it with a screw driver with the car running and see if it goes back to 58, or just take it apart and see what its doing.
TECH Resident
Joined: Nov 2011
Posts: 916
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From: Las Vegas, NV
I'm thinking voltage drop at high rpms, for whatever reason.
Maybe alternator, maybe wires to pumps are too thin. Something. Try hooking up a volt meter and reading it while you go into boost (Have passenger monitor it while you drive). See if there's a voltage drop.
Maybe alternator, maybe wires to pumps are too thin. Something. Try hooking up a volt meter and reading it while you go into boost (Have passenger monitor it while you drive). See if there's a voltage drop.
I was thinking it was regulator too, (I think I'm gonna replace it with a mallory 4305 just to be safe). Even with the vacuum line disconnected from it and it holding a constant 58psi once i got into boost pressure started to drop again. I will drop the tank this weekend and check all the wiring and the pumps to make sure both are working.
I'm starting to think the primary pump is the only one working and not the secondary. I might also remove the alternator and take it to be tested as that is pretty easy to do.
I'm starting to think the primary pump is the only one working and not the secondary. I might also remove the alternator and take it to be tested as that is pretty easy to do.
TECH Enthusiast
Joined: Mar 2012
Posts: 728
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It's a gummed up/faulty regulator, plain and simple. You should be able to support your HP level with just one of those pumps where the pressure drops. You don't need giant fuel lines, aftermarket filter, none of that stuff. The fact that the regulator went down to 45psi with vacuum and didn't come back up to 58 after you removed it proves it's the regulator. Smack it with a screw driver with the car running and see if it goes back to 58, or just take it apart and see what its doing.
A regulator is a mechanical component. With no vacuum lines attached it should be able to hold a constant pressure regardless of flow. Often a failing regulator won't let it be set to a constant pressure or even a high pressure at all. Pressure dropping when the car goes into boost isnt a sign of a failing regulator when the vacuum line is unhooked from the regulator.
