NBS Flex Fuel Pump Replacement

[Fless]

2004 Tahoe, 5.3 Flex Fuel, 105,000 on the clock.

The fuel pump quit on me the other day and it wouldn’t start, but I was able to rap the tank and get it running. I’m ordering the parts I need now to replace it and have a couple of questions.

The Flex Fuel pumps are different from the gas (only) pumps – the Flex’s pump pressure is lower – although the gas tanks appear to be the same from what I can tell. The question for you who have done this on a Flex Fuel NBS is, what besides the fuel pump and spare fuel line clips will I need?

Looking at some of the online resources, GM Parts Direct (& others) doesn’t show a Flex Fuel pump, just the gas (only) pump that states “not Flex Fuel.” But Rock Auto shows two different AC Delco pumps, and I plan to get the MU2294 pump which is indicated for the Flex Fuel.

It seems to include the “fuel sending unit gasket” that’s indicated by the arrow:

And separately that gasket looks like this:

Is that the only gasket I need for this, or do I also need the “fuel pump gasket” o-ring?

Kind of curious if the o-ring is used only on the non-Flex pump, or if it applies to both types.

 

[HiHoeSilver]

2004 Tahoe, 5.3 Flex Fuel, 105,000 on the clock.

The fuel pump quit on me the other day and it wouldn’t start, but I was able to rap the tank and get it running. I’m ordering the parts I need now to replace it and have a couple of questions.

The Flex Fuel pumps are different from the gas (only) pumps – the Flex’s pump pressure is lower – although the gas tanks appear to be the same from what I can tell. The question for you who have done this on a Flex Fuel NBS is, what besides the fuel pump and spare fuel line clips will I need?

Looking at some of the online resources, GM Parts Direct (& others) doesn’t show a Flex Fuel pump, just the gas (only) pump that states “not Flex Fuel.” But Rock Auto shows two different AC Delco pumps, and I plan to get the MU2294 pump which is indicated for the Flex Fuel.

It seems to include the “fuel sending unit gasket” that’s indicated by the arrow:

View attachment 231170


And separately that gasket looks like this:

View attachment 231171


Is that the only gasket I need for this, or do I also need the “fuel pump gasket” o-ring?

View attachment 231172


Kind of curious if the o-ring is used only on the non-Flex pump, or if it applies to both types.

I did my 06 L59. I did not buy ant extra gasket or o ring. My pump is different from the one you listed...Here's a post...

https://www.tahoeyukonforum.com/thr...ahoe-yukon-today.12502/page-2110#post-1177353

There's a follow up post on the next page.

Here's everything I used:

Pump MU1683 rockauto

Retaining ring AC Delco TR26 rockauto

Tank strap clips Dorman 55157 autozone

Line fittings inserts Dorman 800-016
Autozone

 

[Fless]

Interesting, @HiHoeSilver. The pump for my '04 will be different if the catalog is correct. Yours shows just the o-ring but mine has (or should have) the larger black gasket. They must have changed them between '04 and '06.

Good info, thanks for the part numbers for the other stuff, too!

 

[Fless]

@915_Tahoe, would you be able to provide a part number for a flex fuel pump for my '04 Tahoe? VIN ends in 4R199261. Also any required additional gaskets, etc.?

I know that the warehouse folks are on strike, just looking to confirm my info. Thanks in advance; I appreciate it.

 

[HiHoeSilver]

Interesting, @HiHoeSilver. The pump for my '04 will be different if the catalog is correct. Yours shows just the o-ring but mine has (or should have) the larger black gasket. They must have changed them between '04 and '06.

Good info, thanks for the part numbers for the other stuff, too!

05 shows the same as me, so probably one of those 05-6 things... there was a wire harness change somewhere along the way, as in, updated, not a model year change. Mine plugged in to the factory plug. I have read guys that had to splice in a new pigtail, though.

I broke those clips dropping the tank.
I also put a good couple coats of rustoleum bedliner on everything metal.

 

[915_Tahoe]

@915_Tahoe, would you be able to provide a part number for a flex fuel pump for my '04 Tahoe? VIN ends in 4R199261. Also any required additional gaskets, etc.?

I know that the warehouse folks are on strike, just looking to confirm my info. Thanks in advance; I appreciate it.

Do you have the hole vin# since I'm not on the gm server in need the entire vin#.

 

[915_Tahoe]

BY VIN# PART NUMBER 88966962 MODULE KIT, HAS BEEN DISCONTINUED. THE MODULE INCLUDES THE PRESSURE SENSOR 12247409. WHICH IS SERVICED SEPARATELY. FOR AN AC/DELCO MODULE. USE 19337978.

L59 FLEXFUEL 5.3L
FUEL PUMP MODULE ASSEM. GM#19337978 $504.28 AC/DELCO#MU2294
FUEL PUMP SEAL GM#15103734 $55.28 AC/DELCO#G39

 

[Fless]

Do you have the hole vin# since I'm not on the gm server in need the entire vin#.

Thank you

 

[Fless]

Double post due to server latency.