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Discussion Starter · #1 ·
This is a follow on from my other thread.

What kind of fuel pressure you guys seeing @ WOT on 3rd & 4th gear pulls??

I see about 38 at idle and 40-42 sometimes 45 @ WOT, it has sometimes went higher. Just seeing if this is correct. I thought it was supposed to jump up some more under boost???
 

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broke7 said:
This is a follow on from my other thread.

What kind of fuel pressure you guys seeing @ WOT on 3rd & 4th gear pulls??

I see about 38 at idle and 40-42 sometimes 45 @ WOT, it has sometimes went higher. Just seeing if this is correct. I thought it was supposed to jump up some more under boost???
Hmmm. That's odd. One of us has something wrong, just not sure who. I see about 30 at idle, 30-40 cruising at a steady pace, and about 60 at WOT. Autometer Lunar electric FP gauge.
 

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Re: Re: Fuel Pressure @ WOT

NetworkingGuru said:
Hmmm. That's odd. One of us has something wrong, just not sure who. I see about 30 at idle, 30-40 cruising at a steady pace, and about 60 at WOT. Autometer Lunar electric FP gauge.
You are seeing 30psi at idle because the car is pulling around 20inches of vacuum which equates to around -10psi. So the injectors are seeing approx. 40psid. At WOT, if your lower intake manifold is around 14psi, your gauge should be reading around 55psi +/- 5psi (still around 40psi differential).

A car with stock boost will be seeing around 47psi +/- 5psi.

MJ
 

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Discussion Starter · #4 ·
I was reading this on a Diablo Hellion Scan Tool BTW, not a gage.

I once got a FRPS low voltage code, I disconnected the sensor, and plugged it back up, cleared the code and it never came back.

Wonder if this has something to do with it
 

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I see about 27-30 @ idle and not sure @ WOT. Be careful with that FPRS I know of someone who has hurt some bearings because of that failing from gassed down oil!:mad: That along with the fact that someone reported one of their fuel pumps going bad and also resulting in a blown up 03 damn these fuel related problems are scary.
 

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trey193 said:
I see about 27-30 @ idle and not sure @ WOT. Be careful with that FPRS I know of someone who has hurt some bearings because of that failing from gassed down oil!:mad: That along with the fact that someone reported one of their fuel pumps going bad and also resulting in a blown up 03 damn these fuel related problems are scary.
Yea, fuel problems seem to be the most costly of all of the common problems. High boost plus no fuel obviously leads to bad things, but it's hard to believe that too much fuel can be nearly as bad. BTW, wasn't the bearing failures rod bearing failures? Hasn't that always been a weak spot on the mod motors?
 

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I usually see 55-60 psi of fuel pressure at WOT around 25-30 at idle. One thing is bugging me though, I am only reading 18 in of vacuum. Is that normal?
 

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I see about 29 psi at idle on my autometer lunar electric FP gauge. At WOT it's usually about ~50 psi. I did one run down the highway on a track day in 4th gear (had to hurry back home to get my camera) and when I let off my FP was over 80 psi, I'm not sure why it did that.....but that's the highest I have ever seen it go. Oh and if I let off the gas in 6th gear at about 80 mph, I see about 25 in. of vaccum.
 

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would you believe

I Chill Factor's car on the dyno last night.
Ford NGS says fuel psi is steady at 38 all during the run

Auto meter gauge says fuel psi. is close to 60 during the run.
Car made 599hp. With the converters on the car. 93 octane.

I yanked it off threw Jerrys 03 on there..Stock blower car makes 445.. NGS says 41 psi in the middle and 38 psi on the top side of the run.. 11.4
Guess Chill will be alright! But, You would think the thing should be over 50psi atleast.. Who knows..
Its real fast..
 

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delta P across the rail is supposed to be 40 as shown by the NGS. It will fluctuate depending on the PID controller settings. Aftermarket gauges read pressure differently, not as accurate as an NGS.
 
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