LB7 FPRV Shim mod

**2500HeavyDuty** · #1 10-21-2009, 06:51 PM

The lb7 motor as a FPRV just like the lly and lbz motors, except its in a harder to get to location and most of the time its not needed anyway.

The location of the FPRV is located on the fuel junction block in the middle of the valley underneath the metal turbo inlet. The easiest way to get to is it by removing the AC compressor, Thermostat housing and Turbo inlet and you will have a good view of the FPRV.

**2500HeavyDuty** · #2 10-21-2009, 06:57 PM

In the last Picture you can see the return line Tee and Banjo bolt, the Banjo bolt threads into the FPRV. To remove the FPRV undo the 10mm strap holding it in place and hold the FPRV with a 24mm wrench while removing the banjo bolt in the return line Tee with a 19mm wrench.

Here is a pic of it removed.

Now to Take it apart you will need a 5mm Allen wrench and a vice, or something comparable.

Thh contents are spring loaded so be careful when taking the FPRV apart.

**2500HeavyDuty** · #3 10-21-2009, 07:02 PM

Now What i used to shim them with are two M4 washers i got from ace hardware, they fit perfectly in the cap and they are roughly .030" thick each.

**2500HeavyDuty** · #4 10-21-2009, 07:04 PM

Reassemble everything back together as in the last pic in the post above.

And reinstall the FPRV and get back to driving again.

Jet A Fuel · #5 10-21-2009, 07:14 PM

Nice Write up ! Thanks

rosscup · #6 11-02-2009, 10:15 PM

what gains dose this give you?

Diesel Dawgs Performance · #7 11-02-2009, 10:18 PM

**2500HeavyDuty** · #8 11-02-2009, 10:27 PM

Originally Posted by rosscup

what gains dose this give you?

if your FRPV is popping from running high rail pressure adding shims will keep the valve in its seat so it can hold the higher pressure

uwyo_dmax · #9 11-02-2009, 10:37 PM

Thanks Danny Been looking to do this

**2500HeavyDuty** · #10 11-02-2009, 10:41 PM

one tip to get that FPRV out is unbolt the steel return line from the passenger side head and at the steel clamp under the GPCR next the to quick disconnect to give it a little flex so you can unbolt the FPRV easier without seriously bending the steel line.

trust me you want to do that

Dino · #11 11-08-2009, 06:16 PM

Thanks for the info, guys like you are what makes these sites work, Thanks Again

SnoMan · #12 11-30-2009, 11:29 AM

is one of the symtoms of a bad fprv is the truck will surge at idle? Thanks

**2500HeavyDuty** · #13 11-30-2009, 12:06 PM

You probably have a bad FPR or injectors.

SnoMan · #14 12-01-2009, 08:46 AM

Mine isn't doing that yet, I was just wondering, good writeup though

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