5.3 with fuel return to lq9 without fuel return
11-26-2017, 03:59 PM
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5.3 with fuel return to lq9 without fuel return I have just swapped out my old 5.3 to a lq9 with the harness on it. The 5.3 has had a fuel return and the 6.0 doesn't, my truck has the return line. Can I block off the fuel return line on my truck without any issues? I'm really trying to avoid swapping harnesses back since the new one is already in and the old harness had been repaired in a couple places. The new motor came with the pcm and the harness is good so I'd like to leave it like that if I can. If I can just block the return off with no issues then all I'll have to do is change the o2 sensors since the 6.0 harness plugs are different. Thanks in advance
11-27-2017, 08:42 PM
#2
Are u saying the new intake is returnless and your old setup was return? And u wnat to do away with the return setup?
If so u can add a corvette regulator for a returnless setup. U cant just block the return line off bc u dont have a regulator to control psi. The returnless setup has the regualtor built into the feul pump. I would keep the return setup. Just swap rails over.
If so u can add a corvette regulator for a returnless setup. U cant just block the return line off bc u dont have a regulator to control psi. The returnless setup has the regualtor built into the feul pump. I would keep the return setup. Just swap rails over.
11-28-2017, 10:41 AM
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Are u saying the new intake is returnless and your old setup was return? And u wnat to do away with the return setup?
If so u can add a corvette regulator for a returnless setup. U cant just block the return line off bc u dont have a regulator to control psi. The returnless setup has the regualtor built into the feul pump. I would keep the return setup. Just swap rails over.
If so u can add a corvette regulator for a returnless setup. U cant just block the return line off bc u dont have a regulator to control psi. The returnless setup has the regualtor built into the feul pump. I would keep the return setup. Just swap rails over.
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12-06-2017, 09:36 AM
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because the old harness is dry rotted and has several broken wires. If I just swapped the whole intake I would have injectors with 270,000 miles on them defeating the purpose of putting the new engine in plus I would have to un pin the injector connectors and re pin them with the connectors off the old harness. On the old intake the fuel rails mount up higher and the injectors are longer plus the connectors are different. I ended up using the left side fuel rail and just modifying the mounting points. The o2 sensors are different as well so I've got to get the o2 sensors off the donor and use them. I figured it out I just wanted to find the easiest way, which never works for me lol.
12-06-2017, 10:04 AM
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because the old harness is dry rotted and has several broken wires. If I just swapped the whole intake I would have injectors with 270,000 miles on them defeating the purpose of putting the new engine in plus I would have to un pin the injector connectors and re pin them with the connectors off the old harness. On the old intake the fuel rails mount up higher and the injectors are longer plus the connectors are different. I ended up using the left side fuel rail and just modifying the mounting points. The o2 sensors are different as well so I've got to get the o2 sensors off the donor and use them. I figured it out I just wanted to find the easiest way, which never works for me lol.
If your new rail doesn't have a return, then you don't have a fuel pressure regulator anymore, either. Go buy a Wix vette regulator and clip it onto your fuel rail, and then clip your original feed/return onto it. No mods necessary.
You'll have to swap a few pins and things on the new harness to work with your old trans.
12-06-2017, 11:39 AM
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Your old injectors were flex fuel, which is why they were longer. They should be EV6 connectors and flow similar to LS6 injectors.
If your new rail doesn't have a return, then you don't have a fuel pressure regulator anymore, either. Go buy a Wix vette regulator and clip it onto your fuel rail, and then clip your original feed/return onto it. No mods necessary.
You'll have to swap a few pins and things on the new harness to work with your old trans.
If your new rail doesn't have a return, then you don't have a fuel pressure regulator anymore, either. Go buy a Wix vette regulator and clip it onto your fuel rail, and then clip your original feed/return onto it. No mods necessary.
You'll have to swap a few pins and things on the new harness to work with your old trans.
