Too much pump for my regulator?
Thread Starter
Teching In
Joined: Jul 2015
Posts: 42
Likes: 5
Too much pump for my regulator? FYI this is on a 4.3L vortec, but I think there are a lot of people here that could help.
03 S10 4.3L w/ GT35r
42lb/hr Bosch Green Injectors
97-98 Corvette Adjustable Regulator
Walbro 450lph Pump w/ hotwire kit
Factory lines
I did the pump and hotwire kit in anticipation of installing a lq4 and boost. But for now I'm just trying to get this thing running to its full potential and dump some e85 in it for some more fun.
Before the upgrade the pressure was dropping in boost and was running lean. Now its running 68-70psi fuel pressure with or without the pressure reference connected. Truck is setup for 3 bar fuel pressure, and when I first keyed it on the pressure jumped up to ~70psi and dropped to ~43 once the pump kicked off.
I'm thinking it is too much fuel flow for the regulator to bypass, but I also though it could be the return line. The return line is 5/16" from the factory and from research it should be more than enough. I was thinking of buying a piece of fuel line to run from the rail into a fuel can to see if that lowered the pressure, but I am now thinking I need to upgrade the regulator.
Any advise is much appreciated.
03 S10 4.3L w/ GT35r
42lb/hr Bosch Green Injectors
97-98 Corvette Adjustable Regulator
Walbro 450lph Pump w/ hotwire kit
Factory lines
I did the pump and hotwire kit in anticipation of installing a lq4 and boost. But for now I'm just trying to get this thing running to its full potential and dump some e85 in it for some more fun.
Before the upgrade the pressure was dropping in boost and was running lean. Now its running 68-70psi fuel pressure with or without the pressure reference connected. Truck is setup for 3 bar fuel pressure, and when I first keyed it on the pressure jumped up to ~70psi and dropped to ~43 once the pump kicked off.
I'm thinking it is too much fuel flow for the regulator to bypass, but I also though it could be the return line. The return line is 5/16" from the factory and from research it should be more than enough. I was thinking of buying a piece of fuel line to run from the rail into a fuel can to see if that lowered the pressure, but I am now thinking I need to upgrade the regulator.
Any advise is much appreciated.
Thread Starter
Teching In
Joined: Jul 2015
Posts: 42
Likes: 5
Well I finished my test tonight.
Ran a 5/16" fuel line from the rail return into a gas can. When cycling the key to prime the fuel pump it did the exact same thing as I posted above.
So I am going to upgrade the fuel pressure regulator to an aftermarket unit that can handle the flow of my Walbro 450.
Ran a 5/16" fuel line from the rail return into a gas can. When cycling the key to prime the fuel pump it did the exact same thing as I posted above.
So I am going to upgrade the fuel pressure regulator to an aftermarket unit that can handle the flow of my Walbro 450.
Thread Starter
Teching In
Joined: Jul 2015
Posts: 42
Likes: 5
Ok, so after way too long I finally got it working with a new Fuellab mini regulator.
Surprisingly it was even too small to bypass the fuel from my 450 to run a 3 bar fuel pressure. The lowest it would adjust was about 45-48 psi so I bumped it up to run a 4 bar (58 psi) base pressure so it will be able to drop down with engine vacuum.
Surprisingly it was even too small to bypass the fuel from my 450 to run a 3 bar fuel pressure. The lowest it would adjust was about 45-48 psi so I bumped it up to run a 4 bar (58 psi) base pressure so it will be able to drop down with engine vacuum.
