I think you're okay on the sound, but definitely put a reliable fuel pressure gauge on the FPR. Note the reading at the low and high ends of the gauge. Your estimated PSI reading will be in the middle of the low and high readings.

I don't mean to offend, but I had to have this process explained to me. That's why I pass on the info whenever I can. Low fuel pressure PSI reading + High fuel pressure PSI reading / 2 = Estimated "actual" fuel pressure PSI reading.

For example:
If your low fuel pressure reading is 40 PSI, and your high fuel pressure reading is 70 PSI, your estimated "actual" fuel pressure PSI reading is approximately...40 + 70 = 110; 110 / 2 = 55, so your estimated "actual" fuel pressure reading is approximately 55 PSI.

Substitute your fuel pressure PSI readings into the formula and you'll have a good idea of where you're at, regarding fuel pressure.

If your PSI reading was 40 PSI, then you added a BB, I would expect your reading to be in the 65+ PSI area.

 

I've worked with gauges and hydraulics for a while, but we can all learn. If some one gets all butt hurt b/c you gave them info they already had, how would they feel if you held info they needed...lol

Thanks for the reply. trying to find a part number on the spring now. Riff Raff has a kit of some sort with the spring but that dang thing is $60

 

Before doing my pump I was at 35psi at idle. I replaced the pump and did the fpr bb mod and I'm at about 73 psi at an idle now... It smoothed the idle out and I think it improved the power/pedal response a little bit... not much, but some.

 

Yes, Zach. I noticed those same results when I did the BB mod initially, too.

Not related to the fuel pressure issue discussed here, but I also bent the tab on the TPS, so I hear the "click" with a very slight movement of the throttle pedal. Acceleration and overall response was much improved. Something else to tinker with, in case folks don't have enough projects. LOL

 

Ronnie, I've had this situation happen; providing info someone already knew AND "withholding" info they needed. Was YELLED at both times. The kicker...it was the same person. Guess who I stopped helping?

I don't mind if someone tells me the same info over and over. I'm even receiving info from newer members, at several sites to which I belong, that I provided initially. Doesn't bother me one bit.

 

I noticed the smoothness too. Still need to look into getting the fuel pressure up a bit more.

 

Update:

Holy proper fuel pressure batman.....
I disassembled the FPR. I found about 3 coils of my FPR spring lodged in the little metal sponge/filter thingy under the snap ring cover. Guess that would explain 40 psi with a BB and new pump. Back together, fuel gauge was between 78 and 85 psi, but then I started leaking from the snap ring cover Back off and replace cut o-ring

Now a question. All together, no leaks seen, and I'm bouncing from 50-100 psi. OK that is 75 psi on average, but I've not seen that much bounce in any previous test. My gauge is admittedly cheap crap, but.. is that much fluctuation normal? Can you have too much pressure?

Edit: I should mention that the fluctuation is consistently with engine revs.. meaning the highs and lows are in rythm with the "rump rump" of the engine. It was also less noticable (60-95 psi) in high idle.

 

That's a bit to much, normally 5-10 psi fluctuation is normal. Was the fuel pressure regulator one of the updated stiffer versions? If so remove the BB.

 

How do you tell? Maybe I'll just try pulling the BB out and see what happens. The spring I just bought from tasca ford with a ford part number from my local dealer.

 

Spring rate, one spring will be harder to compress than the other. I'm not certain if the OEM spring was updated like the 6.dog's.

 

PULL THE BB! Then recheck. Fuel pressure should be checked at "normal" idle; not high idle. If your high idle pressure is within specs, take a test drive to warm up the engine, and recheck your fuel pressure.

If you have a BB installed and modify/repair the fuel system, (i.e., new fuel pump, new FPR, new FPR spring, etc.), remove the BB and check fuel pressure. The BB is only used to correct a weak FPR spring/failing pump situation. Since you replaced the spring AND the fuel pump, remove the BB. You shouldn't need it now.

Some gauge needle fluctuation is normal, but it depends on the gauge and whether everything else is working correctly. Yours was not, evidenced by the spring coils wrapped up. As long as your average between high and low is less than 80 PSI, you should be fine.

With a new pump, new spring, all "fresh" and clean, I'm betting your PSI will 70+ PSI averaged. That's where mine was when I added the BB with a good working fuel pump.

 

Thanks guys. I'll try pulling it this morning.

 

BB out, still about 40 psi bounce. From 40-80 PSI. Trying to figure out possible causes.



Found this diagram floating around. I labeled green, what I can tell is diagram to physical location reference. Look about right?


If I understand the diagram I see 2 possible causes:
1. Pump oscillation from a piston driven pump that activates once per rev.
2. FPR spool oscillation from ???

I guess I should consider gauge quality as well?

edit: or, the check exiting the piston stage of the pump, man I hope that's not it.

 

is it an oil filled gauge? if not then they bounce a lot as the pump only work when tappet moving up

 

No, it's not fluid filled. I would have the same thought on the bounce. Only reason I question it is that I did not see it the previous 4-5 times I checked my pressure.