LT1-LT4 Modifications 1993-97 Gen II Small Block V8

lt1 fuel pressure drop

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Old Jun 7, 2013 | 03:05 PM
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hey, I have 96 impala ss, le2 383 with 36lb injectors, 255lph pump(do not have the hotwire kit) stock regulator, its at around 46psi with vac on. when i rev it it drops to about 40psi. is this normal or is something going bad? thanks
for any help.
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Old Jun 7, 2013 | 05:00 PM
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Sounds normal. Mine is bad and drops to 28-30....
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Old Jun 8, 2013 | 10:48 AM
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thanks, I was thinking it would go up a few psi when revved
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Old Jun 8, 2013 | 10:55 AM
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you haven't the foggiest idea what you are doing.

The regulator's job is to keep fuel pressure steady when compared to manifold vacuum, what this means is when read by a gauge referencing atmospheric pressure is at times of high vacuum the fuel pressure will appear to drop and appear to rise under low vacuum conditions like WOT.

At idle with the vacuum line on 46 is high, that is about what I would expect with the vacuum line off simulating no manifold vacuum/WOT. Manifold vacuum will spike when you close the throttle after the rev and then you should see the needle drop.

Check the pressure with the vacuum line disconnected.
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Old Jun 8, 2013 | 09:09 PM
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Originally Posted by 96capricemgr
you haven't the foggiest idea what you are doing.

The regulator's job is to keep fuel pressure steady when compared to manifold vacuum, what this means is when read by a gauge referencing atmospheric pressure is at times of high vacuum the fuel pressure will appear to drop and appear to rise under low vacuum conditions like WOT.

At idle with the vacuum line on 46 is high, that is about what I would expect with the vacuum line off simulating no manifold vacuum/WOT. Manifold vacuum will spike when you close the throttle after the rev and then you should see the needle drop.

Check the pressure with the vacuum line disconnected.

Had you not had that first line in there you would have given some great advice AND not seemed like such a *****.....
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