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Fuel Pressure Dropping @ WOT

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Old 05-24-2004, 12:00 PM
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Default Fuel Pressure Dropping @ WOT

While dynoing my car. I notice the my FP dropped from 60 - 40 psi. Even on the street at part-throttle, it drops to 50.

Before I install an inline pump. Is this normal and expected for the power I have??
Old 05-24-2004, 04:04 PM
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You are running out of pump. I would do an intank Walbro pump before an inline pump. The inline pump will help with keeping the pressure up but it will not give you any extra fuel. The inline just can not pull anymore fuel through the stock pump.

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Old 05-24-2004, 05:36 PM
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I hope it will be enough, I already ordered one.
Old 05-24-2004, 06:06 PM
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If you are dropping that hard already trust me it will not be enough even if it looks to be a steady pressure it will not be enough volume.

Nate
Old 05-25-2004, 03:38 PM
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Thank, I was just making sure there was nothing else I should check.
Old 05-25-2004, 03:41 PM
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I would get a good intank in there as well.....

Having fuel pressure drop at WOT with your compression can be playing with fire
Old 05-25-2004, 06:34 PM
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Definitely save yourself some trouble and get a Walbro in there. I hate I dic'd around with an inline all that time.
Old 05-25-2004, 07:47 PM
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You guys have been doing this alot longer that me. I am convinced. If I cannot change the order, I will just order an intake. Anything special I need to order? Or just go through one of the sponsors?
Old 05-25-2004, 08:14 PM
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Just shop the web for the best rate... (and someone who says they have it in stock now).
Old 05-25-2004, 08:15 PM
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I tend to patronize the sponsors here, since they try to accomadate our needs, even if it is a few dollars more (as long as they have it in stock or can get it to me when I need it).
Old 05-25-2004, 08:27 PM
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I agree. I support the sponsors which support the site which help me make an informed decision.

So every kit will have everything I need for the install?
Old 05-26-2004, 01:29 PM
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They do not make an easy kit for our cars to install the pumps. I have the pump and a install kit in stock. I am also offering them installed in the sender as an exchange basis.

Nate
Old 05-26-2004, 07:35 PM
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Hmm, if my pressure is dropping from 62 to 56 would an inline help me? I've got a walbro intank and 42# injectors feeding a 427. Would a vacuum referenced regulater be better? Which one is easier to install?
Old 05-26-2004, 08:18 PM
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What is your Inj Duty cycle at peak RPMs? That kind of pressure drop does not sound unmanageable if it is consistent and enough fuel.
Old 05-27-2004, 02:37 PM
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Originally Posted by Ed Blown Vert
While dynoing my car. I notice the my FP dropped from 60 - 40 psi. Even on the street at part-throttle, it drops to 50.

Before I install an inline pump. Is this normal and expected for the power I have??
After I installed a Ractronix and BAP, I had a pressure drop. Turns out my fuel filter was clogged, huge difference before/after new filter.

Try changing the filter, cheapest and easiest thing to do.
Old 05-27-2004, 05:34 PM
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Once of the first thing I changed. Same issue.
Old 05-27-2004, 08:35 PM
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I changed my Fuel Pump in my 98 to a Walbro 255 pump and I noticed a big difference. It runs a 65 psi and only drops to 59 psi after hard driving
Old 05-30-2004, 10:49 PM
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ED I hate to say it but I had the same problem. Does yours drop just sitting in park revving the engine? mine did. I checked everything. I already had a t-rex fuel punp inline. I added a walbro pump in the tank and it did nothing. I even disconnected my fuel lines and blew them out to make sure something wasnt stuck. I bypassed the filter, the pump and nothing. I tried everything. I gave up and bought rails, braided lines, aremotive eliminator pump, regulator and a sumped tank. problem solved. and it cost around $2,000 to do.
Old 05-31-2004, 12:43 PM
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I haven't notice it dropping when reving. But it does drop at part-throttle.

Wonder if it could be the regulator?? Did you change that out first??
Old 05-31-2004, 01:57 PM
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I changed the regulator too, Only thing is its in the stock pump housing inside the tank. It wasnt that either.



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