Fuel pump EFI - Internal or External, Pros, Cons??

Discussion in 'High Tech Retrofits' started by Aceshigh, May 4, 2006.

  1. Aceshigh

    Aceshigh Veteran Member Lifetime Gold Member

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    I'm buying all my parts for my LS1 retrofit into my 78 Z28 and I'm trying to figure out what is the best route to go for a street car, nothing fancy. I don't have fuel injection as it is right now, so to prepare my car COMPLETELY for EFI it's alot of work. Prepping the tank and installing an internal pump is costing me almost $600 if the figures are correct. This is from Rock Valley prepping the tank for $280 I believe, + $200 for the fuel pump, + like $60 for the vette filter + $$$ for the line and fittings.

    Or is it better to sump it, and do an external ??

    I don't know if an internal pump is better or not.
    I want to know what some of you think and costs for this.
    My car is being sent to a shop for the install and I want to do this the right way, but if it doesn't matter either way, I'd rather go the cheaper route if it's not really a major performance difference.

    I mean.....my current setup is a Gen I 350 with an external pump.
    Any experienced LS1 guys care to comment feel free to throw me a bone here.
    This is the last part I'm stuck on, the rest is done.
     
  2. sbca96

    sbca96 Veteran Member

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    Unless the LS1 fuel requirements differ from the LT1, you should be able to
    use the stock fuel tank, with a 3rd gen pump/sender. I have read this a few
    times on this forum though I dont know the exact details. Perhaps someone
    who has gone this route will chime in. I need to know also for my LT1 setup.

    Tom
     
  3. 3_z28camaro

    3_z28camaro Veteran Member Lifetime Gold Member

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    Most suggest using an in-tank fuel pump. Less risk for starvation. As mentioned before you can use a 3rd gen pump in our tank with minor modifications. I have not done this yet but I just might in the future for an LT1 swap.

    ULTM8Z writes about fuel pumps in here:
    http://www.nastyz28.com/~patgizz/EFIguide.pdf
     
  4. jakeshoe

    jakeshoe Veteran Member Lifetime Gold Member

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    All the OEm's use an in-tank pump.
    Reasons are noise reduction, cooler pump, longer life. They damn sure don't do it for ease of maintenance.

    In tank....

    You could use the 3rd Gen setup but what are you going to do for a baffling system...

    Do the Rock Valley deal....or something similar.
     
  5. Aceshigh

    Aceshigh Veteran Member Lifetime Gold Member

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    Okay, I'll take your word for it. Thanks.
    I KNEW it wasn't for ease of maintenance and THAT was the primary reason I was leary of doing it,
    BUT if it's going to be better performance, then it's a given.
     
    Last edited: May 4, 2006
  6. MikeM79

    MikeM79 Moderator Lifetime Gold Member

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    I hung a Walbro 255 lph pump from a 3Gen sender like this:

    http://www.nastyz28.com/MikeM79Stuff/Stuff/3Genfuelsender.jpg

    The tube curving around the pump is the fuel return.

    I fabbed an "L" shaped drop in baffle / fuel tray from a short section of 3" exhaust pipe and 18 gauge sheet metal. I should have taken a picture of that setup. I have no idea if it really works or not under low fuel conditions because I try to never let the tank get low in the first place. This isn't too hard when the car is a toy....just stop at the gas station on the way home each time the car goes for a ride.





    I love you guys, but I am not going to drop the tank and yank it all apart for the sake of pic. LOL.
     
  7. Knuckle Dragger

    Knuckle Dragger Mayor of Simpleton Staff Member Lifetime Gold Member

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    Third gen sender won't fit the tank on a 79, the hole is different. I tried it on mine. Ace the rock valley stuff is top notch, it's what I'm running. Call in and talk to them in person and you might get a break on the tank, I did. It was a bolt in deal, easy as pie. I cannot recommend them high enough, super guys, superior product.
     
  8. jrc

    jrc Veteran Member

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    I had Rock Valley do my tank. I bought a new tank from NPD for $149.00 and had it shipped straight to Rock Valley. They did the conversion with a Walbro pump. These guys are great. I didn't install the tank until April; they did the tank the previous July. When I unpacked, the sending unit float was damaged in shipping. Gave them a call, and they sent a new piece that day for free, even picked up the shipping. This car has done the Power Tour Long Haul with that tank from Dallas to Green Bay and from Milwaukee to Orlando, no problem. I met alot of guys who were running fuel injection and were having vapor lock problems with their systems, mine didn't miss a lick. Seems like stainless tanks hold alot of heat, and those guys were having problems too. Go with Rock Valley, they know their stuff.
     
  9. Aceshigh

    Aceshigh Veteran Member Lifetime Gold Member

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    Alright, Rock Valley it is.
    They're local so I should have it back quickly too.
     
  10. jrc

    jrc Veteran Member

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    Get the trap door they have and install it in your trunk floor. You can pull your pump without dropping the tank. That's what I did for piece of mind. I keep a spare pump on the shelf and take it with me on the Power Tour just in case.
     

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