2G Will I need an aftermarket FPR with...

[Drop Top Road Trip]

Hi guys. Quick question: if I eventually intall a Walbro 190lph (GSS242 [high pressure] - picked up second hand), will an aftermarket Fuel Pressure Regulator be mandatory?

 

[ErikTande]

Nah, you'll be fine with the stocker and that fuel pump.

 

[Drop Top Road Trip]

Nah, you'll be fine with the stocker and that fuel pump.

Thanks for the quick reply.

 

[JFPryde]

The 190s are fine. The 255s will require the AFPR.

 

[ThunderChild]

you wont need one, but it cant hurt to have one. probably one of the most important part of the fuel system, and the most difficult to get ppl to buy.

 

[Drop Top Road Trip]

I'm new to turbo ownership but read a lot about them back in late nineties / early naughties. Back then a fuel pressure regulator adjusted by boost pressure seemed to be a pretty big deal. Not so much any more? Also, note that the Walbro 190 I picked up is a High Pressure version (actually I also picked up a 225 high pressure at the same time).

Thanks for the even keeled and informative responses to a question that has probably been asked and answered a hundred times.

 

[steve]

The stock fuel pressure regulator is adjusted by boost pressure. If you don't track the changes in manifold pressure the injector flow rate varies, with vacuum "sucking" more in and boost "pinching it off". Not what you want to happen.

The problem with the factory regulator is that it can only flow so much fuel back to the tank and once you exceed that the regulator can't regulate anymore. At idle and low loads, the 255 and larger pumps tend to cause that to happen.