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Discussion Starter · #1 · (Edited)
Some tips for converting the GTO Fuel Bucket to the 8.1L Bucket.

Parts,
8.1L GM Part Number GM#88965372 or AC Delco PN MU1312
Revised Part Numbers GM # 19133455 or AC DELCO PN MU1417
Float Sensor unit part number is GM#88965379

http://www.magnacharger.com
The Magnacharger part number is #31-12-00-026 for the H2 Hummer.
This included the;
1 Fuel Pump, In-tank, Walbro GSS340
1 Fuel Pump Inlet Screen
1 Fuel Pump Sleeve
2 16-14ga. Push On Term Female
1 Fuel Pump Discharge Hose
1 Fitting, Fuel, In-tank Pump

http://www.autoperformanceengineering.com/
APE Flexible Plastic Hose
You may also want to the get the APE Connector instead of the Magnacharger Push on Terminals.
Walbro Connector with Butt Connectors.


You will also need two small hose clamps for the above line and 1 large hose clamp for the Fuel Neck and a box of Heat Shrink Butt Connectors.

UPDATE
A seller on Ebay "ID is global-automotive" sells a complete bucket that INCLUDES the correct Float Sensor.

Also if your careful you can use the 8.1L buckets flex line and attache the GTO connector to the end of the flex line so you only have 1 worm clamp.
Thanks to those who keep finding out more information on this setup.

Picture of Finished Bucket.


Removing the tank,
http://www.lingenfelter.com/sites/l...es/L710660504 GTO fuel pump upgrade v4.41.pdf

Over View,
Remove the fuel tank and pull the GTO Bucket.
Unclip the two Connectors from the top of the bucket
Remove the C Clip from the rod and separate the upper and lower section.
You will use the Upper half on the 8.1L Bucket so place it somewhere safe.

Modify the 8.1L Bucket.
See http://magnacharger.com/pdf/manual-HummerH2.pdf
Steps 20 though 42
The only difference is you will NOT be keeping the upper half.
Don't attach the bottom cover just yet.

Now you want to use the GTO Connectors and Butt Connect them to the 8.1L wires.
Take care that you get positive and negative correct on the Fuel pump.
If you use the Magnacharger kit you will use the spade connectors on the GTO wiring.

For the Float sensor wiring,
Place both Sensors in front of you. The new one points right and the GTO one points left.
Using the GTO connector Butt connect the left wire to the left wire of the new Float Sensor.
You can verify the correct wiring by using an OHM Meter. Empty is the higher number while full is a lower number.

Now you can connect the GTO Upper half to the 8.1L lower have. Slide the rods into the bucket and use the C Clip to hold it together. Attach the 8.1L bottom to the Bucket now. To line it up correctly the GTO upper half will be at the 3 O'clock position and the Float Arm will point to the 2 O'clock position.



This was the hardest part at the time but I found a better solution.
Making the fuel line that attaches to the tank,

Use a razorblade knife and cut the tubing off the connector that attaches to the fuel tank. Do the same thing for the 8.1L 90 Degree Connector that comes off the Fuel filter.

On both Connectors sand the barbs down enough to you can get a good fit with the APR Flex Line then use a hose clamp on both connectors.





Snap the 90 Degree Connector back into the Fuel Filter.



You're done and it's time to reassembly.

Thanks to PO04GTO and b727pic for helping me out.

I drove around town with the "You Need Fuel Stupid" flashing at me and had no problems.

I hope this help. Any questions??
 

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Discussion Starter · #4 ·
About $400. No WOT tests yet.

I wasn't having a fuel problem but with the new heads I wanted to make sure I would be ok when it hits the dyno for tuning.

Displacement
No the warning light is when you get low on gas. Your DIC lights up when you hit those RED marks on the Fuel Gauge.
 

· Old Guys Rule
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Good to see its done, and have a thread for others to follow...

Thanks Dan
 

· ...
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Outstanding work
...thanks for paving the way.

.
 

· Administrator
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Trailblazers rule. good job and nice documentation!
 

· Old Guys Rule
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Should probably get this put into the Knowledge base section.....
 

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Discussion Starter · #9 ·
I'll give DY a heads up.
 

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Hey ddawson , where does the loose pipe go? Does it plug into the top of the sender?
 

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Discussion Starter · #12 ·
No. There is a hardline in the tank that it connects to.

See pictures from b727pic's site


There is another hose in the tank that attaches to the top part of the fuel bucket.
 

· I like boobs.
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I'm assuming you put the springs back on the rods?
 

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Discussion Starter · #14 ·
You use the spring in the 8.1L bucket. That's why you need to use the C clip to keep the two halfs together.
 

· 2/23/2007 = [email protected]
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Attn: ddawson,

Very nice!

I'd like to do the Fuel Bucket upgrade you outlined. Could you verify these are the parts needed:

1. GM Parts:
a. 8.1L GM Part Number GM#88965372 or AC Delco PN MU 1312 (Cost = ?)
b. Float Sensor unit part number is GM#88965379 (Cost = ?)


2. Magnacharger pn#31-12-00-026 for the H2 Hummer. PN# includes the following parts:
a. 1 Fuel Pump, In-tank, Walbro GSS340
b. 1 Fuel Pump Inlet Screen
c. 1 Fuel Pump Sleeve
d. 2 16-14ga. Push On Term Female
e. 1 Fuel Pump Discharge Hose
f. 1 Fitting, Fuel, In-tank Pump

Note: Could not locate this pn# on there site. How do I locate, or order? Cost for this pn#?

3. Parts from "Auto Performance Engineering"
a. APE Flexible Plastic Hose (Correct Part = Flex Hose? $2.50)
b. Walbro Connector with Butt Connectors (Correct Part = Pigtail? $3.30)

Question: Is b the part you referred to ..... "you may also want to the get the APE Connector instead of the Magnacharger Push on Terminals"

4. Aditional parts needed:
a. 2 small hose clamps for the above line (APE Part "Hose Clamp" .60 each?)
b. 1 large hose clamp for the Fuel Neck (Clamp Size?)
c. Box of Heat Shrink Butt Connectors (any particular size?)

Question: Best place to buy b and c?

About how long would you say this project takes from start to finish?

Appreciate your undertaking this project and the o/s write-up.

Thanks!
 

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Discussion Starter · #17 ·
Check ebay. They should be around $200 there. Otherwise it's $$$

The Sending unit cost me $100 from PO04GTO but he no longer works at a dealership.

The ebay one comes with a sending unit but I don't know if it's the right one.
It has to be short enough to fit correctly in the fuel tank.

For the #31-12-00-026 you need to call Magnacharger and order. I talked to Tony and the price was $120.

From APE the pigtail is the correct locking connector for the Walbro. It's not necessary as the #31-12-00-026 comes with push on terminals. It's just that the pigtail would be a more secure connection.

The clamps you need are much smaller then the one APE sells. I picked up two small worm clamps from Orchard Supply along with a larger one for the Fuel Neck.

A 3” clamp would be fine for the fuel neck and a small ¾” one for the hoses should be fine.

APE sells the Heat Shrink Butt Connectors but I used the ones you get from the auto parts store. 14-16 AWG size.

I would have been done in 1 weekend but I ran into the feeding tube problem. Luckily b727pic found that APE sold the hose I needed to complete the project.

At this point I could do it in a day because I’m familiar with it now. I used the LPE Fuel Pump Upgrade guide for my instructions along with the Magnacharger H2 one for the modifications. http://www.lingenfelter.com/documents/gtofuelpumpupgrade.pdf
 

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Discussion Starter · #18 · (Edited)
jasonblair said:
What does this bucket thing do, exactly?
It allows you to run low on fuel without staving the fuel pump.

The GTO bucket doesn’t allow enough fuel into the bucket with a high flow pump. The pump will suck the bucket dry leaving the pump with no fuel and no cooling.

People have added holes to the bottom of the GTO bucket which fixes the supply issue but as the tank runs low the holes allow the fuel to drain out of the bucket again leaving the pump with no fuel. This is turn burns out the pump.

You can see in the last picture if you look closely that there is fuel in the bucket sitting on my driveway. No fuel is leaking out.

The 8.1L bucket allows enough fuel to enter the bucket without modification and also doesn’t allow the fuel to drain out when the fuel tank gets low.

At this point we know it can supply 500HP which is fine for me but I don’t think we know were the 8.1L bucket becomes a limiting factor again.
 

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excellent work. thanks so much for doing this!

You could probably come up with a rough calculation of how much power it can support by guesstimating how much more fuel it will flow. Is the weakest link in the chain that little fuel inlet thing at the bottom? measure the inside diameter of the old and new one and that would give us a *rough* idea.
 

· 2/23/2007 = [email protected]
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ddawson,

Thank you for the additional information. Now to get my ass in gear!
 
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