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boosted truck. fuel pressure drop at WOT and at shifts.

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Old 01-01-2005, 05:47 PM
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Default boosted truck. fuel pressure drop at WOT and at shifts.

Ok, i've read several posts from several different guys with boosted trucks that say their fuel pressure drops to 50 at WOT. Mine does the same thing. Does anyone know what the problem/solution is?
Old 01-01-2005, 06:29 PM
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It is a fuel supply problem-the pump just can't keep up. My truck started doing that early on, so I put a boost-a-pump on it (already had it laying around) After installing the BAP I could go WOT and when the gauge started to drop I would turn the **** for the BAP and the needle on the gauge would jump right back to the proper pressure. This worked for me for about 2 years until the stock pump gave up. Now I have 2 high pressure 255 Walbros in the tank with the BAP hooked up to the primary pump. Even now when running on just 1 pump I get the drop unless I have the BAP turned up about 1/2 way.
Old 01-01-2005, 09:57 PM
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I have the boost-a-pump that came with my whipple. I was thinking about hooking it back up to see if it makes any difference. How do I power it? There are 3 wires, red, grey, and blue.


also, i just took the truck out for a spin again. From a dead stop, if i floor it the fuel pressure goes up to 70, then slowly goes down to 40 until it shifts, then jumps back up to 70, then slowly back down again. WTF?????
Old 01-01-2005, 10:17 PM
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40 isn't good. If you got a boost pump with your whipple, you should be running it.
Old 01-01-2005, 10:23 PM
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you should have 55 or so minimum
Old 01-02-2005, 12:03 PM
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the bap...is it in line or what...im installing my 43# injectors this next week and dont want to have anymore fuel leaning probs at wot.is there a inline that will just come on when you start the motor and stay on all the time.
Old 01-02-2005, 02:00 PM
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Bad things can happen if you run out of fuel up top ...
Old 01-02-2005, 02:09 PM
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Originally Posted by Flyer
Bad things can happen if you run out of fuel up top ...

Sure can
Old 01-02-2005, 03:50 PM
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so can anyone tell me what booster pump to get and what its gonna take to hook it up
Old 01-02-2005, 03:59 PM
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For on 04 truck, you should upgrade the in-tank pump. Look at magnachargers website under support. There you'll find install PDF files. Read over the 04 file, its got instrustions for installing a walbro GSS340 fuel pump.


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