Bypass cooling fuel through IP metering?

[AndyL]

How does the fuel metering through the IP work? The fuel that flows from the tank to IP and back?

I was thinking of using a different lift pump. One, because the factory units are unreliable. And two maybe increasing the fuel pressure could possibly cool the IP more for increased reliability.

[BuffaloGuy]

Andy,
If you increase the fuel flow too much you can have a problem with the fuel foaming. The pump that gm designed does just what is needed, just enough but not too much. My first lift pump went 90,000 miles and the one I have now has went 120,000 miles. Pretty reliable in my book. However, I have plumbed in a fuel pressure gauge after the filter housing. This will let me know when it does go out and it also informs me of when the filter REALLY needs changed. Hope this helps, just my .02.
Ken

[AndyL]

For us DB4 guys, is the opinion there is already enough fuel cooling for the IP?

Can someone describe the plumbing flow from the tank:pump:filter:IP:injectors:tank for me?

[kowsoc]

I believe lift pump does not determine the VOLUME of fuel flow, just the pressure. This is because the Stanadyne pump has an internal vane pump that meters the fuel flow according to RPM. I think the pump has an internal pressure regulator that gives 15 psi in the pump. Any extra pressure relieves back to the tank. The vane pump is the reason the pump will still work even when the lift pump stops working. My truck probably ran for a month before I realized the lift pump was not pumping.....just a skip at hard throttle, like a misfire in a gasser.

[AndyL]

So conceivably we could remove the vane and use a say 20 PSI lift pump? Probably not worth it I guess.

[toyboxrv]

I had a 6.2 where the internal pump was weak and would cause a lack of power when warmed up. I borrowed a Holley electric that could make 20 psi to test my theory of low internal pressure. It made a huge difference in power, smoked like a train and had rapidly increasing exhaust temps until I lifted the throttle. I ended up replacing the injection pump but removed the electric to prevent any potential meltdown of my motor. I wouldn't suggest trying to increase power by using a high pressure fuel pump, but what do I know.

[Jim P]

I know a guy who has a John Deere 4010 pulling tractor that has a roosemaster injection pump. This pump is real similar to the mechanical stanadyne pumps but only for 6 cylinders. He took out the vanes in the pump and uses a hydraulic pump driven of the fan belt to feed the ip. He is running 200 psi of fuel pressure. It is putting out about 400 hp.