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Could someone explain returnless systems?

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Old Mar 15, 2008 | 08:07 PM
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Default Could someone explain returnless systems?

I put an aftermarket efi system on my 72 pontiac 400 with an external fuel pump; the pump that came with the kit. i drove it today on the highway for about half an hour before i hit unexpected traffic. i slowed the car down and the car bogged and shut off. i am running one vent line from the tank to above the tank to outside air.

i'm starting to hear that returnless systems are not as reliable as return systems, but i know some ls engine cars have returnless systems. has anyone had experience with them? would running a return line make that much of a difference even if i'm properly vented? why make returnless systems at all if they're in fact unreliable? i planned on having my ls1 powered car a returnless system but now i'm not so sure.

a buddy of mine said that my external fuel pump on my 72 firebid's system could very well be overheating; that at cruise i should be fine but sitting in traffic some of them are known to overheat. anyone else have this issue? do you recommend any external fuel pumps for daily drivers with an aftermarket efi system?

i know that's a lot of questions but it was totally embarassing pulling over on the side of the road over and over today.

thanks for any help/advice guys
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Old Mar 22, 2008 | 02:40 PM
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Going to have to agree with your buddy sounds kinda like the pump is overworked and getting to hot. The return style systems is really needed for high HP cars(600+). The vettes are the only ones that come stock with them. Making a return set up isn't that hard to do. Check through the fueling and injection section --> prob a better place to ask also.
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