LT1-LT4 Modifications 1993-97 Gen II Small Block V8

Fuel pump replacement procedure?

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Old Jan 5, 2017 | 11:03 PM
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Default Fuel pump replacement procedure?

Sometime in the next week I plan to attempt changing the fuel pump in my 1994 Z28 that I've found already has the trap door mod from a previous owner. I have zero experience with fuel pumps so I'm trying to research actually changing them out but all I can seem to find are dozens of posts online about how to make the trapdoor mod on these cars. Not an actual step by step procedure of removing the old pump and installing the new one with new wiring and what not. I pulled the old pump out of the tank today just to see if maybe when the previous owner replaced it, some wiring was done incorrectly or had disconnected but I didn't see anything that looked damaged or out of the ordinary.

Im still waiting on my new pump to get here so maybe it will have directions with it but besides that, are there any actual write ups of replacing the pump itself out there? Any help would be great because I want to learn, I'm just having issues trying to find anything about it. Thanks
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Old Jan 6, 2017 | 12:03 AM
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Default 94 fuel pump

I would have to say the easy way is to cut a access door the fuel pump is pretty much in the middle behind the back seat. I dont have any pictures right now on mine but I can post one tomorrow. You just have to be carefull not to cut to deep and cut your fuels lines. There is videos on youture of people doing it. Doing it this way will save you a few hours.
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Old Jan 6, 2017 | 12:41 AM
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Like I said in my post, the previous owner has already done the access door mod so that's the step I'm not interested in and I've already pulled the pump assembly out of the tank. I'm just looking for a procedure on how to go about disassembling the pump itself from the assembly and installing a new one since I've never actually done it before
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Old Jan 6, 2017 | 07:27 AM
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Once you pull the pump its pretty straight forward, Now many get rid of the bucket and just mount the pump. First you will have to see what the previous owner did then go from there, send pics when you pull the pump and people will chime in on helping you out..
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Old Jan 6, 2017 | 10:06 AM
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Originally Posted by moehorsepower
Now many get rid of the bucket and just mount the pump.
Don't do this. The bucket is crucial for the longevity of the pump. If you don't have the bucket installed the pump will overheat and the lifespan will be cut short. The bucket is there to cool the pump once the regardless of the fuel level in the tank. I'm not sure if there's still an install kid sold with fuel pumps, but it should include the glue needed to reseal the bucket once you cut a lid on the top using a dremel. Also, there is something about the inlet being offset or centered or something like that. There are ribs in inside the bucket and you may have to cut them out in order for the pump to fit correctly. Perhaps someone with more knowledge can post up with that. Regardless, do not get rid of the bucket.
Most likely it's not the original pump? Get a bucket if you don't have one.
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Old Jan 6, 2017 | 11:47 AM
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If it's an OEM replacement pump, it will include the bucket and will just be a matter of connecting a hose or two to the sending unit, plugging in the wiring harness, putting everything back in the tank, reconnecting the lines, electric etc.

If it's an aftermarket pump, like a Walbro, the bucket will not be included and the process will be a bit more involved. The Racetronix site might be helpful if you bought a non OEM pump.

I bet if you google LT1 fuel pump replacement, you'll get some helpful hits.

I've always dropped the tank, which was by far the most difficult part of replacing the pump.
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Old Jan 7, 2017 | 01:31 PM
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Alright here are some quick pics I took of it while I was home for lunch today. I only ordered the pump itself off eBay from a place I read some good reviews from. HFP 255LPH pump. And I've googled a lot of fuel pump replacement stuff but I can only find people that talk about making the trap door mod.

I don't see any spliced or cut wiring to indicate someone replaced it in the past
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Old Jan 7, 2017 | 01:32 PM
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I've replaced my fuel pump by dropping the tank. Not too bad, nothing complex. I got rid of the bucket. As long as you keep your tank at least half full, you will be fine. I did my first fuel pump over 10 years ago.
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Old Jan 9, 2017 | 06:48 AM
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Originally Posted by BOLO
I've replaced my fuel pump by dropping the tank. Not too bad, nothing complex. I got rid of the bucket. As long as you keep your tank at least half full, you will be fine. I did my first fuel pump over 10 years ago.
Yup, I run dual pumps so no bucket and have had no problems for years, but again I try and never run my tank less than 1/4 full
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Old Jan 9, 2017 | 07:22 AM
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From: Jackstandican
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Well yeah, if you keep the pump(s) submerged then there should be no problem, but there's no reason to discard it if it's readily available.
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Old Jan 18, 2017 | 02:52 PM
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Okay so after having the flu for a week and then working all the next one, I finally have a day off. I've got the bucket and pump separated from everything now. So I'm wondering, if the previous owners glued the bucket shut, how should I go about separating it without breaking the lid? Maybe just some heat to heat the glue up?
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Old Jan 18, 2017 | 03:32 PM
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Well that worked better than I expected. Just wanting to be safe with it and not break anything. I removed the old pump which turned out to be a cheap Airtex E3270. Maybe that's why it failed? It looks quite smaller than the 255 replacement pump I bought
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Old Jan 18, 2017 | 05:04 PM
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From: Jackstandican
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Originally Posted by LT11996
how should I go about separating it without breaking the lid? Maybe just some heat to heat the glue up?
Yes. Try that first. If it refuses to come off then cut the seam using a dremel.
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