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fuel pressure and air/fuel ratio Please HELP...:(

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fuel pressure and air/fuel ratio Please HELP...:(

Old 11-17-2005, 07:23 PM
  #1  
1.5 BAR
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Default fuel pressure and air/fuel ratio Please HELP...:(

quick set up background.

walboro fuel pump
golden eagle fuel rail
Sx fuel pressure regulator
AEM wideband gauge

And here is my problem.

Moving the screw on the FPR clockwize will increase fuel pressure, therefore the air fuel ratio should go RICHER, and vice versa.

But in my case it does the absolute opposite. The fuel pressure goes up but the car runs LEANER.

The wideband is good, I checked that.
The FPR is good, no leaks in the diaphragm
Changed the fuel filter

Im so stumped that I don't know what else to do.

any imputs will be considered. thanks so much.

UPDATE 12/01/05 :

I also changed:

fuel injectors
fuel pressure regulator
fuel pump
blew air through the return line
changed the banjo line form the filter to the fuel rail, with a AN-6 line
checked voltage at the fuel pump, 11.7v with car been sitting for a week
checked pressure of the fuel pump, over 100 psi with no return

Again, doing the same thing. I just don't know.
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Old 11-17-2005, 07:24 PM
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Default Re: fuel pressure and air/fuel ratio Please HELP...:(

Need more fuel than the pump can supply or get there?


JP
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Old 11-17-2005, 07:36 PM
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Default Re: fuel pressure and air/fuel ratio Please HELP...:(

it does not make sence. this is with the car at idle, the pump should pump way more than what the car needs.

with the car at idle, I disconect the vacume hose from the fpr and the pressure goes up, but the car runs leaner. I makes no sence.
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Old 11-17-2005, 07:39 PM
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Default Re: fuel pressure and air/fuel ratio Please HELP...:(

At idle, huh? Hmmm, your right it would have PLENTY. Or should. Anyway to check BEFORE the FPR. Try a stock FPR? I don't know. You said it's fine though. Hmmmm....


JP
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Old 11-17-2005, 07:43 PM
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Default Re: fuel pressure and air/fuel ratio Please HELP...:(

Originally Posted by samson
At idle, huh? Hmmm, your right it would have PLENTY. Or should. Anyway to check BEFORE the FPR. Try a stock FPR? I don't know. You said it's fine though. Hmmmm....


JP
yea im in the same boat
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Old 11-17-2005, 08:46 PM
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Default Re: fuel pressure and air/fuel ratio Please HELP...:(

Originally Posted by 98ctr
quick set up background.

walboro fuel pump
golden eagle fuel rail
Sx fuel pressure regulator
AEM wideband gauge

And here is my problem.

Moving the screw on the FPR clockwize will increase fuel pressure, therefore the air fuel ratio should go RICHER, and vice versa.

But in my case it does the absolute opposite. The fuel pressure goes up but the car runs LEANER.

The wideband is good, I checked that.
The FPR is good, no leaks in the diaphragm
Changed the fuel filter

Im so stumped that I don't know what else to do.

any imputs will be considered. thanks so much.
sooo.... turn it the other way and it will go richer, no?
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Old 11-17-2005, 10:32 PM
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Default Re: fuel pressure and air/fuel ratio Please HELP...:(

^^^ no, cuz when I hook up the vacume hose it goes richer and when I go to WOT or boost it will go leaner.
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Old 11-17-2005, 10:54 PM
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Default Re: fuel pressure and air/fuel ratio Please HELP...:(

just a theory here but it makes sense.

you say at idle you pull off the vacuum hose and the pressure goes up and it reads leaner? No idea why if you turn the fuel pressure up it reads even leaner....but plug the manifold hole so the RPMS don't go up and adjust it that way.
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Old 11-18-2005, 08:58 AM
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Default Re: fuel pressure and air/fuel ratio Please HELP...:(

^^ I did. when I adjust the fuel pressure I put a bolt in the hose from the manifold so the rpm's stay at about 900 where I have it set.

im gona see if anyone in the area has the same fpr and see if I can try theirs, so I know if that is the problem or not.
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Old 11-18-2005, 09:05 AM
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Default Re: fuel pressure and air/fuel ratio Please HELP...:(

sounds like it's possibly the fpr, that's what was happening to me when i tried raising my fuel pressure with a known bad fpr, it would run leaner at idle with the fuel pressure raised.
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