Fuel Pressure Reg. And Mpg

[94expl]

I Have A 94 Xlt With About 160000 Miles On It And 32" Tires And I'm Getting About 11 Mpg At The Most And I Have Heard Alot Of People Talking About How Replacing Your Fuel Pressure Regulater Helped Their Gas Milage. I Was Wondering If Your Check Engine Light Doesn't Come On If Its Still Possible To Have A Defective Pressure Regualter. Thankszach

 

[sparky2263]

If the fuel pressure regulator was bad, it would set a rich code. Then, replacing it would improve mileage.

I'd think that 11 mpg with 32" tires ain't bad.

 

[94expl]

thanks sparky

 

[MrShorty]

BAD FPR can set a code (either rich or lean depending on the exact failure), but not always. EEC-IV doesn't directly monitor fuel pressure and doesn't always see the fault through the O2 sensor. Rather than just randomly replacing the FPR, check the vacuum line for gas (one common failure mode for the FPR) and then put a fuel pressure gauge on the rail and see what the fuel pressure is. If the fuel pressure is correct and the FPR isn't leaking, I doubt changing it will do much