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Old August 11th, 2015, 1:22 PM
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check engine light, stabilitrak, traction control, bank 1 & 2 lean

Old July 30th, 2013, 2:16 PM
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yeah, its just frustrating. I mean i tried to do as much research as i could to figure out this problem, but seems like no one really knows what the problem is. There is some consilation in knowing that it could have been more if i went to a dealer and had them try to fix it, but I can't say I'll feel any better when I go down the same road that everyone else has replacing everything on the truck and dump a 1000 bucks into it and still have the same problem. As I replace things hopefully someday, one of them will actually fix the problem. I'll keep posting as I go through the process so that hopefully i can save someone from doing the same thing and wasting a bunch of time and dumping a bunch of money into their vehicle for no reason.

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Old July 30th, 2013, 10:38 PM
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okay so same reading po171/174 bank1/2 lean. So I checked the fuel pressure again and it was showing 43/44 so my fuel pump was fine. turn the engine off and fuel pressure slowly climbs, all the way to 70/72 as soon as i start the engine, it hold for about 10 seconds at 58 and drops down to 43/44. I'm assuming the only other thing this could be is the fuel pressure regulator? any thoughts, any and all help would be greatly appreciated.
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Old July 31st, 2013, 12:12 AM
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been trying to do research, but haven't found anything on how to replace the pressure regulator. i thought i read somewhere that its under/built into the intake manifold. can anyone confirm or deny where the heck its at and/or give me any pointers on how to swap it out........i'm looking at trying to get the part tomorrow and swap it out. again, any help would be greatly appreciated.
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Old July 31st, 2013, 1:23 PM
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Okay, doing more research and it looks like the "fuel pressure regulator" for my 5.3L AFM motor is actually a fuel pressure sensor? Is that correct?
Its also my understanding that this sensor is built into the fule pump assembly. If thats the case, I have a hard time believing that both fuel pumps had bad sensors, so is there something else I'm missing? could it be the connector, relay, fuse, something like that? i would think the sensor power and fule pump power would be from the same source so if one had a power issue they both would? I'm in desperate need of some help here.
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Old July 31st, 2013, 2:28 PM
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I don't have access to my service manuals at the moment so I can't provide much info... I may be able to this evening though...as a suggestion you might try getting the 1yr subscription to All Data diy as they have the 07 info and it can help you identify and repair lots of stuff.. its basically the factory repair manual on line...
IF you Google alldata diy coupon you can get a couple bucks off the $15 yr subscription...
Old July 31st, 2013, 7:33 PM
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The documents I have don't show a regulator for the 5.3 ?
Old July 31st, 2013, 10:51 PM
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yeah, the research i was doing initially said the regulator was built into the air intake manifold and you had to remove the manifold to replace it. i haven't been able to find that site again and everything i've found since doesn't show a regulator, just a sensor on the fuel pump.
is there anything else i can do to troubleshoot? anyone understand why a brand new pump would have a low pressure issue? what actually regulates the pump pressure to the fuel injectors? if its the pcm or ecm, what would make it reg the pressure down from 58 to 44? i'm lost, any help would be appreciated? maybe remap the ECU/ECM?
Old August 3rd, 2013, 12:32 PM
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well since ive been working for dodge i havent had hands on a 5.3 in a while but the last version i worked on the fpr was just clipped on the drivers side fuel rail and vacuum actuated so you could just unplug the line to check it
Old July 18th, 2016, 3:33 PM
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Sorry for not closing the loop on this post, but in the end after all the troubleshooting I did and the money I wasted on a new fuel pump the issue was a vacuum leak.
There is a plastic tab on the aft passenger side of the plastic intake manifold that looks like the top on a kids fruit juice bottle that got clipped when I removed the engine cover and reinstalled it.
I didn't see it the vacuum leak wasn't very load and it took forever to pin point it. Seems like a poor design, but the fix is simple, just get a quart inch rubber nipple and cap it.
I'll have to take pics and post them so people can get a visual.
Old September 4th, 2016, 1:18 PM
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Default Same issue

Originally Posted by jphurst36
Sorry for not closing the loop on this post, but in the end after all the troubleshooting I did and the money I wasted on a new fuel pump the issue was a vacuum leak.
There is a plastic tab on the aft passenger side of the plastic intake manifold that looks like the top on a kids fruit juice bottle that got clipped when I removed the engine cover and reinstalled it.
I didn't see it the vacuum leak wasn't very load and it took forever to pin point it. Seems like a poor design, but the fix is simple, just get a quart inch rubber nipple and cap it.
I'll have to take pics and post them so people can get a visual.

Thank you for sharing! I'm going through the EXACT same thing with my vehicle right now! We were thinking it was the fuel pump but I'm glad I found your post. Do you mind sharing the picture of what your replaced?

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