Fuel pressure spring

If you're getting that much pressure out of the pump you don't have the right one. Pumps for carbs don't put out much pressure and you don't need a regulator.

 

[FONT=Geneva,Verdana,Tahoma,Arial,Helvetica,Sans-serif]Truck Engine News[/FONT] [FONT=Geneva,Verdana,Tahoma,Arial,Helvetica,Sans-serif]
2009/04/01
[/FONT]A New Spring Kit for the Fuel Transfer Pump Is Now Available.
Most guys like it at 100PSI or just over when under load.
See Attached PDF........ Keep in mind this spring kit only fits the later pumps and wont Fit the pumps on engines like 6NZ 9NZ

 

Thanks for that info, I was about to suggest a new transfer pump. I guess I'd make a good mechanic/parts changer at a dealership - just change parts until it's fixed! hahaha

 

The scary part is when you buy a new pump it has the old type spring in it.... So Next you buy a new pump also buy a spring kit

 

I would replace the fuel bypass valve to start with,about $25.

 

I dont think the fass is a issue the fass puts out about 15 psi and it takes about 85-100 psi to open the fuel return check valve. I would start with the return check valve and go to the transfer pump next.

 

The Cat lift/transfer/fuel pump is a gear pump. Neither a FASS nor an Air Dog will push fuel through it. They will push air but not fuel. All the relief spring in the transfer pump is for is to protect the pump if the outlet is plugged! The ACTUAL delivery pressure is regulated by the Pressure Regulator built into the filter/return housing. 70 to 90 lbs. seems to be the norm, mush more & the transfer pump will try to cavitate, much less & the fuel rail for the injectors will begin to lose pressure toward the front of the engine, ie, try to starve #1 or #2 cylinder.