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Fuel pressure drops off in boost. :::::::::::::HELP::::::::::::

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Old 10-01-2007, 12:38 AM
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Default Fuel pressure drops off in boost. :::::::::::::HELP::::::::::::

OK so POS LS-t EG is kicking my ***. Prob In boost fuel drops off and A/F's go into 15'sish before i can let off. So far ive replace, fuel filter, FPR,walbro pump, re-wired pump to alt voltage and double checked voltage at pump. Their has too be some kind of restriction in the fuel system but i cant figure it out any ideas?

Setup is a LS-t, 35e, Fatty delta cams, skunk 2 valve springs, walbro 255, deka 550's, 22psi+110


Oh yeah and its snapped 2 timing belts and bent 4intake valves in the last week
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Old 10-01-2007, 02:23 AM
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Default Re: Fuel pressure drops off in boost. :::::::::::::HELP::::::::::::

Put a toggle switch on all 4 ground wires going from injector to ECU.
Put vise grips on return line.

Go WOT and flip toggle switch. Guaranteed to rip.

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Old 10-01-2007, 02:26 AM
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Default Re: Fuel pressure drops off in boost. :::::::::::::HELP::::::::::::

Originally Posted by leed
Put a toggle switch on all 4 ground wires going from injector to ECU.
Put vise grips on return line.

Go WOT and flip toggle switch. Guaranteed to rip.

ill try that hopefully this t-belt last more then 15mins
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Old 10-02-2007, 11:28 PM
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Default Re: Fuel pressure drops off in boost. :::::::::::::HELP::::::::::::

Bump for sweet ride. Im out of idea's.
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Old 10-02-2007, 11:33 PM
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Default Re: Fuel pressure drops off in boost. :::::::::::::HELP::::::::::::

I think stock exhaust and exhaust manifold is going to fix this problem
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Old 10-03-2007, 02:04 AM
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Default Re: Fuel pressure drops off in boost. :::::::::::::HELP::::::::::::

Originally Posted by 88dx
I think stock exhaust and exhaust manifold is going to fix this problem


Can you watch it on a gauge drop in boost or are you assuming its dropping?You try putting some air through the feed line to make sure it is not clogged?Check the strainer in the tank?
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Old 10-03-2007, 02:21 AM
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Default Re: Fuel pressure drops off in boost. :::::::::::::HELP::::::::::::

Originally Posted by 90dx


Can you watch it on a gauge drop in boost or are you assuming its dropping?You try putting some air through the feed line to make sure it is not clogged?Check the strainer in the tank?
Yeah fuel pressure gauge taped too the windsheild, drops around 20psi before i let off. When i replaced the Fuel pump/filter i blew the line out. The new walbro dosent have a strainer, but the first one did and was new. theirs plenty of gas 5 gallons or so .

i need too take the head back off too replace the bent valves from the 2nd broken timming belt
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Old 10-03-2007, 11:01 AM
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Default Re: Fuel pressure drops off in boost. :::::::::::::HELP::::::::::::

walbros have been known to be dodgy. if your 550cc injectors are wide open, then the pump has to push 2.2l of fuel per minute at boost + base fuel pressure. thats quite a bit. what size are the stock lines fwd and back? what sort of fpr do you have? is it properly referenced to the manifold? hmmm
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Old 10-03-2007, 12:49 PM
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Default Re: Fuel pressure drops off in boost. :::::::::::::HELP::::::::::::


You aren't using one of those lame *** B&M style FPR's are you?

Those things are crap.


If you are, I'll post why later.


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Old 10-03-2007, 01:02 PM
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Default Re: Fuel pressure drops off in boost. :::::::::::::HELP::::::::::::


Also, is this a High Pressure walbro or the regular one?



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