Thread: fuel pressure is 40 at idle.....

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  1. #1 fuel pressure is 40 at idle..... 
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    so when i turn my key and the fuel pump engages it reads 43 and then when i start it, it idles at 40. i know its supposed to be 48-55, then a 3-10psi drop at idle. is this enough to mess things up? i am having issues when hittin the gas goin up a hill or just tryin to get on it. ive narrowed it down to preatty much a cat or low fuel pressure. what should i do first? maybe get a voltage booster and hi flow fuel filter first? then just eliminate the cat and get an emulator?
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  2. #2 Re: fuel pressure is 40 at idle..... 
    GT Level Member SlowRR's Avatar
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    When was the last time you changed plugs and wires. I had a bad set of wires causing me all kinds of problems. Namely a nasty misfire but only under boost. Just a thought
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  3. #3 Re: fuel pressure is 40 at idle..... 
    The mod from over yonder TheOtherNick's Avatar
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    High flow filters are a scam. Leave the gauge hooked up and drive and see what it is while driving if it drops below 40 change the filter and if it still does time for a new pump
    01 gtp-big cam e85 dd 78dodge- guzzling fuel 05 cummins- rollin coal
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  4. #4 Re: fuel pressure is 40 at idle..... 
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    damn. when i drive what rpm should i reach. i just got a cheap rented autozone gauge so i dunno how well i could read it while driving.and i got plugs and just replaced wires a week ago and it runs a hell a lot better but still stutters. what is the misefireing/tach jumping? is that kr? or somethin else. what about the voltage booster? that is suposed to giv the fp more juice and raise psi? would that really give me a few psi?
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  5. #5 Re: fuel pressure is 40 at idle..... 
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    its above 40, but is that still too low?
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  6. #6 Re: fuel pressure is 40 at idle..... 
    The mod from over yonder TheOtherNick's Avatar
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    Should be ok, change the fuel filter, run some seafoam threw the tank first.
    01 gtp-big cam e85 dd 78dodge- guzzling fuel 05 cummins- rollin coal
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  7. #7 Re: fuel pressure is 40 at idle..... 
    GTP Level Member 01gpgt01's Avatar
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    Quote Originally Posted by alivepills View Post
    its above 40, but is that still too low?

    48 is with vacuum not applied. I run mine 40-42 with vacuum
    2001 GT. A few here and there mods http://www.streetfire.net/video/2001...ynp_208097.htm

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  8. #8 Re: fuel pressure is 40 at idle..... 
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    seafoam wont screw up my injectors? wtf. anyways... i didnt know that you were suposed to dissconnect the vac line to get the correct fuel pressure reading... are you sure?
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  9. #9 Re: fuel pressure is 40 at idle..... 
    GTX Level Member QUICKSILVER462's Avatar
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    Disconnecting the vacuum line just tells you that the regulator is adjusting in relation to maifold pressure. 43.5psi @0 vacuum is what it should be, and around 37psi with vacuum hose connected, depending on idle vacuum.
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  10. #10 Re: fuel pressure is 40 at idle..... 
    GTP Level Member 01gpgt01's Avatar
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    Quote Originally Posted by QUICKSILVER462 View Post
    Disconnecting the vacuum line just tells you that the regulator is adjusting in relation to maifold pressure. 43.5psi @0 vacuum is what it should be, and around 37psi with vacuum hose connected, depending on idle vacuum.

    37 is low. 42 is where you want to be under vaccum and around 48-50ish with no vacuum, and yeah you're supposed to go off the non vacuum numbers.
    2001 GT. A few here and there mods http://www.streetfire.net/video/2001...ynp_208097.htm

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  11. #11 Re: fuel pressure is 40 at idle..... 
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    this stumble that i thought was an engine misfire for the longest time turned out to be in my tranny. my car would accelerate through the stumble if i taped the brakes while still giving it gas. leading me to believe it was the torque converter lockout solinoid. kind of a pain in the ass. but readin on here some ppl told me to just disconnect my battery to reset my pcm, because it might be the pcm messin everything up. well that turned out to work perfectly. now my question is with the pcm . do i need to replace this to prevent this from happening again? and what brand pcm will work best for me? i dont plan on any big mods just exhaust and some minor stuff.
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