When Checking FPR....
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Logistics Pro
Joined: Oct 2004
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From: FL
When Checking FPR....
Hey Guys, I decided that today I would check and see what i'm getting for fuel pressure. I bought me a new dial gauge, and stuck it on there. The gauge went on fine and the dial move back and forth from 40-60 PSI. Now..... Which number is the one i'm supposed to go by, i'm guessing the higher one, but i thought i'd check.... and should i bother to shim the fpr or not?? thanks 
-Robb
-Robb
Last edited by Robbgt; Mar 18, 2005 at 05:13 PM.
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Joined: Aug 2004
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From: SHELTON, WA
i hope you dont mind but i am gonna jump in too. i also did this and i took 3 readings 48,48 and 50. i was gonna make a similar thread and then i saw this. also are you guys using a bb from a bb gun???????? or is it a different size? thanks
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Joined: Jun 2004
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From: Perkins, OK
Originally Posted by 1997F-350
i hope you dont mind but i am gonna jump in too. i also did this and i took 3 readings 48,48 and 50. i was gonna make a similar thread and then i saw this. also are you guys using a bb from a bb gun???????? or is it a different size? thanks
Thread Starter
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Logistics Pro
Joined: Oct 2004
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From: FL
hum.... thanks for the response, but i'm wondering how i was supposed to be reading the gauge? i have a dial one and when i stuck it on there at idle it pulsed back and forth from 40-60 constantly, and didn't even off at a particular number, so i'm not sure what # i should be going by, the lower or higher of the two. thanks again...
-Robb
-Robb
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Joined: Feb 2002
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From: Bonney Lake, WA
You'd want to use the higher number. Many/most find that 60 to 75psi is the optimum range, so if you're already at 60, you might not see much benefit from shimming.
1997F-350- Since you're at 48-50, you have more opportunity for improvement. A 3/16 bb works well for some, but I used a #4 cap screw, and inserted the threads into the end of the spring before putting the spring back into the cup. My original fuel pressure was in the low 40's, and found that the cap screw didn't raise the pressure enough, so I added a washer on the screw before reassembly. That put my pressure at 76psi. Since I felt like tinkering that day, I added a second washer, and found my pressure to be at 85psi, but the idle got lumpy, so I backed off to only one washer.
Click here for a pic of the components involved.
1997F-350- Since you're at 48-50, you have more opportunity for improvement. A 3/16 bb works well for some, but I used a #4 cap screw, and inserted the threads into the end of the spring before putting the spring back into the cup. My original fuel pressure was in the low 40's, and found that the cap screw didn't raise the pressure enough, so I added a washer on the screw before reassembly. That put my pressure at 76psi. Since I felt like tinkering that day, I added a second washer, and found my pressure to be at 85psi, but the idle got lumpy, so I backed off to only one washer.
Click here for a pic of the components involved.
