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85 Vette Fuel Pump

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Old 07-12-2007, 10:52 PM
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Car Freak
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Default 85 Vette Fuel Pump

Hi all! I posted here for the first time almost 7 months ago but can't find thread? Car still isn't running but at least it cranks now because that was one of the two problems! My carpenter an x-stereo alarm guy figured it out in 10 minutes, something to do with the alarm! I think I have the other problem of not starting is faulty fuel pump! Don't hear it turn on when the key is first turned? A friend put his finger on the schrader valve and said yes there is fuel in there but he thought it should shoot out rather then seep out and he believes the fuel presssure should be about 40 pounds? So my question now is, do you have to pull the tank to replace pump?

Thanks in advance!

Car Freak or was that Car Fool for having too many cars? lol!!!
Old 07-12-2007, 11:16 PM
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Midnight 85
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You don't have to pull the tank, take off the fuel door by lifting it up and removing the screws under it. With that out of the way you will see a rubber boot, CAREFULLY take it out. It tears easily so be careful. Once the boot is out you can see the tank and all you have to do is take the screws out around the perimeter of the cover you see, remove the hoses noting where they came from for replacement. Just lift up on the cover and the fuel pump will come with it. Don't forget to replace the sock too. By far the easiest fuel pump R&R you will ever do.
Old 07-13-2007, 12:26 AM
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John A. Marker
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....easy to replace. Took me about 1/2 hour. Pay attention to which way the sock is on the pump and which way it is located in the tank.

Fuel pressure for an 85 should be 36-40 PSI with the vacuum line to the fuel pressure regulator disconnected and plugged.
Old 07-13-2007, 09:32 AM
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Originally Posted by Midnight 85
You don't have to pull the tank, take off the fuel door by lifting it up .
Thanks guys! Good news for a change! One little question, are you saying that I don't have to remove fuel door, just lift it up and I will have enough clearance to get the rest out?

Thanks
Old 07-13-2007, 09:34 AM
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Originally Posted by Midnight 85
Don't forget to replace the sock too.
When you say replace, do you mean with a new sock or the existing one? Thanks again!
Old 07-13-2007, 09:42 AM
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rons85
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when you open the fuel door you can see four small screws ( same as interior trim screws), in the corners of the base, that hold down the door and base assembly. Take out those four screws and the door/base will lift straight up and off. Now you can pry out the rubber boot. Then all is revealed...

The sock at the end of the pump Should come with the new pump - just make sure it's aligned the same way as the old one. You have to press the sock onto the end of the pump after you stick the pump onto the sender assy. It's also cheap insurance to replace the Pulsator (the connecting link between the pump itself and the line on the sending unit assembly) while you are in there... That is something you have to buy separately.

Oh - also not a bad idea to get a new Gasket for the sender assy when you buy the pump (it Won't come with the pump..). This is the square-ish shape gasket between the sender assy and the tank itself. You may be able to re-use the old one OK, or not..
Old 07-13-2007, 10:26 AM
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Thanks Rons85!
Old 07-13-2007, 10:29 AM
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CFI-EFI
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Don't just throw money at it. Diagnose and confirm that the pump is bad before you replace it. It is difficult to translate the length of the squirt out of the Schrader valve into psi. Check your fuel pressure with a gauge. You say you don't hear the pump run when you turn the key. You DO know that the pump is only supposed to run for about 2 seconds when you turn the key, right? Is there power to the pump? Is the fuse good? Is the fuel pump relay, relaying? How is the fuel filter?

RACE ON!!!
Old 07-13-2007, 04:09 PM
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FrankCandid
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Originally Posted by rons85
It's also cheap insurance to replace the Pulsator (the connecting link between the pump itself and the line on the sending unit assembly)
Please excuse the mild hijack.

Is the "Pulsator" the rectangular plastic piece with the 3 wires coming out of the top and bottom?

If so, I'd appreciate it if someone let me know where can I get one as well as a complete sending unit - they seem to be discontinued at AC Delco Canada.

Thanks.
Old 07-13-2007, 04:14 PM
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engle1147
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This is a picture of pulsator: (top piece)
Old 07-13-2007, 04:22 PM
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Man that was fast!

Thank you, sir!

I'd better start a new thread for my questions.
Old 07-15-2007, 10:06 AM
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Originally Posted by CFI-EFI
Is the fuel pump relay, relaying? How is the fuel filter?

RACE ON!!!
Hi! I replaced the fuel filter! Is the fuel pump relay easier to replace then the pump itself and where exactly is it? I also checked fuses and they look to be good. Thanks
Old 07-15-2007, 10:49 AM
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Fuel pump relay is at the back of the left rocker cover on the firewall. just unclip the wire harness connector, and remove the two screws that hold it to the firewall. a 1/4" ratchet, a 9/32 socket with a universal and extension gets it good

Last edited by coupeguy2001; 07-15-2007 at 10:52 AM.
Old 07-15-2007, 11:01 AM
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Originally Posted by coupeguy2001
Fuel pump relay is at the back of the left rocker cover on the firewall. just unclip the wire harness connector, and remove the two screws that hold it to the firewall. a 1/4" ratchet, a 9/32 socket with a universal and extension gets it good
Thanks! Nice avatar! What color is that 85? charcoal?
Old 07-15-2007, 11:40 AM
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Originally Posted by Car Freak
Hi! I replaced the fuel filter! Is the fuel pump relay easier to replace then the pump itself and where exactly is it? I also checked fuses and they look to be good. Thanks
Unbelievable. It isn't an either/or situation. You don't replace the easiest one to get to. You trouble shoot to determine what the problem is, and then you fix or replace the cause. Your FSM has a trouble shooting chart just for this problem, if you can't reason your way through it.

RACE ON!!!
Old 07-15-2007, 11:57 AM
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Originally Posted by CFI-EFI
Unbelievable. It isn't an either/or situation. You don't replace the easiest one to get to. You trouble shoot to determine what the problem is, and then you fix or replace the cause. Your FSM has a trouble shooting chart just for this problem, if you can't reason your way through it.

RACE ON!!!
I don't have all the necessary tools and it beats having it towed to the dealer! I do have a gauge to check cylinder compression but I don't think I can use it for this application?

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