Fuel in the FPR vaccum hose?

[Pro3racer]

Recently i started getting worse gas mileage. Then one day my aftermarket boost gauge stopped working, and i would get a little backfire here and there. I pulled the plastic line on my gauge out of where i tapped into the FPR line, and gas came out, and not like one drop, not pouring out, but there certainly was gas in the line(an air line). I instantly looked towards my FPR leaking, so i got a working on i had, and put it on. My boost gauge is still not working, i still have the little backfire, i still have bad gas mileage. Any ideas on this, i know the boost gauge works, i tested it out of the car with an air hose, it moves with pressure. This is kind of urgent too please. Thank you very much.

 

[Talesin]

Sounds like the diaphragm on your FPR either burst or developed a wear hole/crack. With gas in the FPR vac line, it isn't going to do its job... you're likely running either way too rich or way too lean.

Short version: To fix the problem, replace your FPR and disconnect the vac lines, blow all the gas out, then reconnect. Should start working again perfectly.

 

[Pro3racer]

I know i need a AFPR with my 255 pump, but it has made it about a year without a hitch. My new FRP is in perfect condition, and i know i am running way to rich, my blinky light gauge is almost always rich now, instead of going its usual course. Is there a reason i am not getting boost readings? My idle is perfect too.

 

[Pro3racer]

oh, and i also have all the vaccum lines elimated by taboos race setup, so i only have the FPR line going into the intake manifold and Tee'd with my boost line.

 

[Talesin]

Heh. A 255 without an AFPR will overrun the stock FPR pretty easy on a 1G. When I bought my GSX, it had the same thing (Walbro 255 HP with a stock FPR), and we couldn't figure out why I was running so rich until we checked the pressure... was something ludicrous like 62psi at idle. MAJOR overrun.

But yeah, that's almost certainly the problem... likely burst or cracked the diaphragm. Grab an Aeromotive and the fitting set. I got the Import Evolution 'IE-FPR' kit for 200, and toss a underhood fuel pressure gauge on one of the spare taps while you're at it to make life easier when you need to adjust or check the pressure.

 

[Pro3racer]

I know i need an AFPR, but i have run the car like this for almost a year, and the previous owner ran it for another year like this. My friends cars(dsm's) also run this setup and don't have the problem. It would be one thing if the regulator was just not regulating and i were to be running rich, but throwing gas into a vaccum line seems to me to be a whole different thing, am i wrong here?

 

[Talesin]

Just because it worked in the past does not mean it SHOULD run that way. There's a reason people get an AFPR when they go up to a 255. The stock FPR is *not* sufficient, will not give a good fuel pressure baseline, and will fail. It's like asking a condom to hold back Hoover Dam. It might semi-work for a while, but sooner or later it is GOING to break, as that was not its designed application.

Get the right parts, do it right the first time. Using slapdash hacks like that when a designed solution is available is just begging for problems.