Questions on a Fuel Pressure Regulator.

[tom1995tsi]

I just installed my walbro 255, the car runs really good. I have heard some people say you def. need a fpr and others say you dont really need one. My question is if i get a new fpr how would I know what to tune it to, would I need a datalogger? Thanks for the help guys.

 

[DSMNightmare]

You'll need a fuel pressure gauge either in car or under the hood. Also if you can make sure you get a FPR that is adjustable both up and down. I'm one of the people who has a 255 high pressure pump and does not use a FPR. That being said I'm not going to open that can of worms. But I will say this... if it aint broke dont fix it.

 

[psychlow]

If you get an AFPR, you just set it to stock base fuel pressure. If you change the base fuel pressure, you'll want an SAFC and a logger to mess with your fuel settings.

If it's running fine, you might be okay on the stock regulator, but you could probably get better idle/low throttle response and gas mileage with an AFPR. They usually more than pay for themselves over time, especially the way gas prices are right now.

 

[tom1995tsi]

What would the symtoms of a overrun stock fpr be? Just so i know if i need to get one.

 

[psychlow]

Poor gas mileage, stumbling, choppy idle, idle searching, black, sooty spark plugs, black smoke in the exhaust at low throttle/RPM

 

[TalonspoolAWD]

What about WOT. I have a 1G with a AGP 50trim,680cc injectors, Walboro 255LP, STock FPR,FMIC. I am running about 22psi and with my logger it will show about 14-18 counts of knock at .82V but the car pulls REALLY GOOD. If i tune for no knock at .86-.88volts and get no knock then the car does not move good and on a 1st gear launch it will just break up like crazy like its to rich same in second at the higher RPM's ALong with all the other gears it will break up around 6200 and feel slower I thought it was to lean but putting it on the WB 02 sensor it shows like 10-12.1 at WOT. For some reason i dont see how this logger can be correct. It says my high Fuel trim is 110, but if i richen it up the trim will not change and 1st and scond gear are USELESS, on a launch it will just studder. I have my AFC set to about -25-28 for the High and the WB02 says i am RICH AS HELLm WHILE THE LOGGER SAYS .86-.88 and a FT of 110.5, and its says i am lean for the low trim at around 107, and the low is at -17. I am using a 2G MAF in my 1G also. BASICALLY Its like i can get it to pull good and have knock then it will pull like crap with less knock. If i give the knock up the car runs like shit, if i have the knock it pulls EXTEMELY HARD, and the 02 voltage is like .80-.82. Anyone got any ideas

 

[psychlow]

I doubt that's your AFPR. Not quite sure what your problem is - might try the tuning forum.

 

[dave99gst]

on a 2g the stock FPR is more capable to manage the pressure then a 1g.
base 2g pressure is 43 psi. if your car does not have a re-wired fuel pump and the walbro isnt a 255 HP then your prob fine. IF it is a 255HP and you did rewire it then you are prob over-doing it.

 

[TalonspoolAWD]

255LOW pressure with Stock regualtor and wiring, along with 680cc injectors, does the FPR have any affect when i am WOT
Thanks
Tom