Fuel Pressure Issue
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Teching In
Joined: Nov 2001
Posts: 44
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From: South Florida
Fuel Pressure Issue Having some problems and would like some ideas.
I have an ATI with the 3.4 pulley seeing at max 10lbs of boost. I have 42lb injectors and the inline Aeromotive pump which GWP supplys with thier stage II kit.
I recently put in a new cam and started to run lean. I've been using LS1 Edit to try to get the car back on the rich side.
I usually see 62lbs of fuel pressure once the inline pump comes on and that amount stays constant.
As I've tuned the Injector flow rates to get away from the lean condition, I've seen the pressure start to drop under boost. It now starts at the 62 and move down slowly to around 52-54. I replaced all the wiring on the inline pump to make sure that wasn't the issue. Didn't help.
I've check the pulse width on the injectors and max duty cycle they are seeing is just over 80%.
Any ideas what I should check?
My thoughts....
Failing fuel pump
Bad regulator
Maxed the fuel system when I lower the IFRs
I've got two days at Sebring this weekend so I'm pretty eager to get this solved. Any input would be great.
Thanks.
I have an ATI with the 3.4 pulley seeing at max 10lbs of boost. I have 42lb injectors and the inline Aeromotive pump which GWP supplys with thier stage II kit.
I recently put in a new cam and started to run lean. I've been using LS1 Edit to try to get the car back on the rich side.
I usually see 62lbs of fuel pressure once the inline pump comes on and that amount stays constant.
As I've tuned the Injector flow rates to get away from the lean condition, I've seen the pressure start to drop under boost. It now starts at the 62 and move down slowly to around 52-54. I replaced all the wiring on the inline pump to make sure that wasn't the issue. Didn't help.
I've check the pulse width on the injectors and max duty cycle they are seeing is just over 80%.
Any ideas what I should check?
My thoughts....
Failing fuel pump
Bad regulator
Maxed the fuel system when I lower the IFRs
I've got two days at Sebring this weekend so I'm pretty eager to get this solved. Any input would be great.
Thanks.
Re: Fuel Pressure Issue i had that same problem
it turned out to be the fule system was barely keeping up.
i put an intank walbro and kept the aeromotive, now pressure is always at 62 ( sometimes it goes a bit higher <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" /> )
it turned out to be the fule system was barely keeping up.
i put an intank walbro and kept the aeromotive, now pressure is always at 62 ( sometimes it goes a bit higher <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" /> )
Teching In
Joined: Nov 2001
Posts: 40
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From: Pasadena, Maryland
Re: Fuel Pressure Issue </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by 1dirtyZ:
<strong>i had that same problem
it turned out to be the fule system was barely keeping up.
i put an intank walbro and kept the aeromotive, now pressure is always at 62 ( sometimes it goes a bit higher <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" /> )</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Did you change your intank pump? That could be the culprit or the inline itself and that would be the first two places I'd look. I'm assuming that you're already running a large intank fuel pump? Another thing that comes to mind is a good fuel pressure regulator that is boost sensitive (1:1) and not sure if you have that either but a great addition.
Take care and good luck,
Tim
<small>[ December 18, 2002, 08:52 PM: Message edited by: 1BadAzzGT ]</small>
<strong>i had that same problem
it turned out to be the fule system was barely keeping up.
i put an intank walbro and kept the aeromotive, now pressure is always at 62 ( sometimes it goes a bit higher <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" /> )</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Did you change your intank pump? That could be the culprit or the inline itself and that would be the first two places I'd look. I'm assuming that you're already running a large intank fuel pump? Another thing that comes to mind is a good fuel pressure regulator that is boost sensitive (1:1) and not sure if you have that either but a great addition.
Take care and good luck,
Tim
<small>[ December 18, 2002, 08:52 PM: Message edited by: 1BadAzzGT ]</small>
Re: Fuel Pressure Issue I m having the same problem. But I got the stock intake pump, and the ATI inline pump, with 42# inj. And when I m under boost it drops to 50-53psi, but when at idel, or regular driving, it's at 61-63psi.
So have u figured out ur problem? or can u give me and idea of what I should look for.
thnks
Mike
So have u figured out ur problem? or can u give me and idea of what I should look for.
thnks
Mike
TECH Addict
Joined: Nov 2001
Posts: 2,207
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From: College Station, Tx
Re: Fuel Pressure Issue With and aeromotive inline and stock intank you are probably running low on fuel volume - I would either pull the stock intank totally and just hook up a 12an feed to the aeromotive - or you could go to one of the dual pump racetronix setup's.
An ATI size inline and the stock pump just may not be able to keep up - especially at the high fuel pressures that LS1's use. You most likely need one of the two solutions outlined above (albeit with an aeromotive inline instead of a walbro if you go that route)
Chris
An ATI size inline and the stock pump just may not be able to keep up - especially at the high fuel pressures that LS1's use. You most likely need one of the two solutions outlined above (albeit with an aeromotive inline instead of a walbro if you go that route)
Chris
