FPR Shim Question

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Mar 2, 2005 | 11:12 PM

Roamineye

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From: Perkins, OK

FPR Shim Question

I shimmed my FPR last night using a BB, and it made quite a difference in the way the truck runs - more throttle response and smoother idle. I measured the pressure using just a regular tire gauge, and it bumped it from ~50 psi to ~70 psi at idle, according to my gauge. I've read that 70 psi is optimum, so I'm happy. My question is this: How accurate is my tire gauge measurement? Has anyone checked a tire gauge measurement against a measurement with a gauge that's designed to work with liquids? Guess I'm a little paranoid that my measurement could be off - I don't want to over-stress the fuel pump.

Mar 2, 2005 | 11:17 PM

ltfox

Fleet Mechanic

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From: CentralEastern Utah

I put together a clip-on tire chuck,1/4 inch needle valve and a liquid filled gauge to check mine. It works real good. The needle valve can control the spikes and the liquid filled helps some also. Clip it on the tire chuck on the scherader valve and start the truck. I never could get a consistent reading with a tire gauge.
I'm lucky enough to work in the oil/gas business and have access to such stuff!

Last edited by ltfox; Mar 2, 2005 at 11:20 PM.

Mar 2, 2005 | 11:39 PM

Roamineye

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From: Perkins, OK

Quote:

Originally Posted by ltfox

Thanks for the reply - sounds like a good idea. I had trouble getting good readings, too, but just took several until I had pretty consistent results. But consistent doesn't necessarily mean accurate.

Mar 2, 2005 | 11:52 PM

96ford4x4turbodiesel

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From: Gainesville, Texas

hey if yall could give me a little help...where exactly is the fuel pressure regulator at....is it on the drivers side of the fuel bowl?....if so which is the one im supposed to take off to shim?

Mar 3, 2005 | 12:02 AM

Roamineye

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From: Perkins, OK

Quote:

Originally Posted by 96ford4x4turbodiesel

hey if yall could give me a little help...where exactly is the fuel pressure regulator at....is it on the drivers side of the fuel bowl?....if so which is the one im supposed to take off to shim?

Yes, the FPR is on the driver's side of the fuel filter housing. You need to pull the 3/4" brass plug out and remove the little spring and the metal plunger. You may need to use needle nose pliers to grab the spring, and a magnet to get the plunger out. Remember the orientation of the spring, because you'll want to put it back in the same way. Put the shim into the hole in the plunger where the spring goes. Put the spring in on top of the shim. Install the plunger and spring back into the housing, and put the brass plug back on, making sure the spring sits over the little tit on the brass plug. Then you're in business.