Fuel Pump Question

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RAMurphy

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2002 Tahoe with nearly 300,000 miles on the frame (Engine and Transmission have been rebuilt). Long time follower and as I was updating my profile I realized that my fuel pump is still the original pump. This beast still runs so strong and is still so very solid from a ride perspective, but then again I've changed/replaced most of the components throughout the years since I purchased it new back in 2002. If it was easy to change I would most likely change it just to be safe. My gut tells me that I should change it from a preventive perspective. Don't want to be left in the middle of nowhere when it decides to fail. Thoughts? Would I get an indication before it fails?
 

JohnTN

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Hey RM,

I've got a 2002 Tahoe LS with 228,000 miles, going strong with original engine and transmission. It's in the shop right now for a second fuel pump, first one replaced at 103,000 miles. In both cases, it was lights-out when it failed with no advance warning. Seems 100,000 miles is about the normal lifespan for these GM fuel pumps, so you've done well!

I'm not aware of any warning signs. At 300k, I'd say get it before it gets you and leaves you on the roadside. Unfortunately it's not an easy change - pump out the gas, drop the tank, replace the fuel pump module, put the tank back and pump the fuel back in. In my two experiences, its been about a $1000 job each time.

All the best,
John
 

rockola1971

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#1 killer to fuel pumps is people running the tank below 1/8 tank and getting on fumes. The fuel is used to cool the fuel pump and heat will cause the motor windings of the fuel pump to run too hot which eventually breaks down the coating of the wire windings ultimately causing an electricl short across the windings which causes excessive power to be consumed which ultimately causes the winding to burn in half (broken wire) then its game over. This is how just about any type of electrical motor fails excluding bearing failure.

The GM truck platform usually gets around 125k on a fuel pump module but again it is very dependent on how often and how low the tank is ran low, amount of crap that goes through the pump that the strainer doesnt catch and im sure excessive cold or hot season (weather) can play a role too.

Always replace with a OEM AC Delco/Delphi pump module. The aftermarkets just dont have a great track record.

Me personally at your high mileage and if you intend on keeping the vehicle for awhile then I would go ahead and get it done.

Sometimes when a fuel pump is planning on dying it will cause the vehicle to need to be cranked more than once on a cold start (a leaky fuel injector can cause this symptom too). Other times the pump will just die without any warning and often hours after the tank was jsut filled which makes the job so much more fun. When the engine starts getting stubborn to start on the first crank it could be weeks, months or even over a year before the pump dies or could be minutes until death.
 
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RAMurphy

RAMurphy

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Thank you for the quick replies. Rarely do I let the tank get below a 1/4 tank (grew up where it gets really cold). Old habit. Yep, figured I was most likely going to need to replace it before I'm left hanging out in the middle of no where. Still starts right up and no other symptoms but that is a lot of miles on that fuel pump. I will get underneath this weekend and see if the straps are all in good shape and judge the complexity of this job. If I can swap out an engine, I'm sure I can tackle this job. Just need to find a video. Again, thanks. Bob
 

rockola1971

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Thank you for the quick replies. Rarely do I let the tank get below a 1/4 tank (grew up where it gets really cold). Old habit. Yep, figured I was most likely going to need to replace it before I'm left hanging out in the middle of no where. Still starts right up and no other symptoms but that is a lot of miles on that fuel pump. I will get underneath this weekend and see if the straps are all in good shape and judge the complexity of this job. If I can swap out an engine, I'm sure I can tackle this job. Just need to find a video. Again, thanks. Bob
Its stupid easy to drop the tank. JUst make sure you have the fuel line connector tool set that releases the locking clips at the connector of each fuel and vent line. Thats really the only thing you need special. Some compressed air to blow off trash around the locking ring that holds the pump module in place and a replacement Oring(gasket) if one is not supplied with your fuel pump module (they usually are). Dont be surprised if your lock ring needs replaced too so you might want to get one of those ahead of time. They are cheap enough.
 

2006Tahoe2WD

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#1 killer to fuel pumps is people running the tank below 1/8 tank and getting on fumes. The fuel is used to cool the fuel pump and heat will cause the motor windings of the fuel pump to run too hot which eventually breaks down the coating of the wire windings ultimately causing an electricl short across the windings which causes excessive power to be consumed which ultimately causes the winding to burn in half (broken wire) then its game over. This is how just about any type of electrical motor fails excluding bearing failure.

The GM truck platform usually gets around 125k on a fuel pump module but again it is very dependent on how often and how low the tank is ran low, amount of crap that goes through the pump that the strainer doesnt catch and im sure excessive cold or hot season (weather) can play a role too.

Always replace with a OEM AC Delco/Delphi pump module. The aftermarkets just dont have a great track record.

Me personally at your high mileage and if you intend on keeping the vehicle for awhile then I would go ahead and get it done.

Sometimes when a fuel pump is planning on dying it will cause the vehicle to need to be cranked more than once on a cold start (a leaky fuel injector can cause this symptom too). Other times the pump will just die without any warning and often hours after the tank was jsut filled which makes the job so much more fun. When the engine starts getting stubborn to start on the first crank it could be weeks, months or even over a year before the pump dies or could be minutes until death.
I didn't know about running the tank low and the pump motor running a bit hot. Good tip and another reason to keep the tank above say 1/4 full.
 

89Suburban

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I didn't know about running the tank low and the pump motor running a bit hot. Good tip and another reason to keep the tank above say 1/4 full.
I refuse to let it go below half.
 

iamdub

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#1 killer to fuel pumps is people running the tank below 1/8 tank and getting on fumes. The fuel is used to cool the fuel pump and heat will cause the motor windings of the fuel pump to run too hot which eventually breaks down the coating of the wire windings ultimately causing an electricl short across the windings which causes excessive power to be consumed which ultimately causes the winding to burn in half (broken wire) then its game over. This is how just about any type of electrical motor fails excluding bearing failure.

The GM truck platform usually gets around 125k on a fuel pump module but again it is very dependent on how often and how low the tank is ran low, amount of crap that goes through the pump that the strainer doesnt catch and im sure excessive cold or hot season (weather) can play a role too.

Always replace with a OEM AC Delco/Delphi pump module. The aftermarkets just dont have a great track record.

Me personally at your high mileage and if you intend on keeping the vehicle for awhile then I would go ahead and get it done.

Sometimes when a fuel pump is planning on dying it will cause the vehicle to need to be cranked more than once on a cold start (a leaky fuel injector can cause this symptom too). Other times the pump will just die without any warning and often hours after the tank was jsut filled which makes the job so much more fun. When the engine starts getting stubborn to start on the first crank it could be weeks, months or even over a year before the pump dies or could be minutes until death.

The pump is in its own bucket that it fills when running, so it's always submerged regardless of the fuel level in the tank. Been this way for decades.

Another myth is letting it run low makes it suck up trash from the bottom of the tank. The pump pulls from the bottom of the tank at all times.


However, I would suggest, especially with an older/higher-mileage pump module, to keep it above ~1/8 tank. The level sensors commonly go bad and read the level inaccurately, making the gauge show more or less than what you actually have in the tank. If it sputters during a moderate acceleration and your gauge still shows to have enough fuel to not trigger the low fuel warning, then it's likely reading inaccurately and you actually are on fumes.
 
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RAMurphy

RAMurphy

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All good responses. My OEM parts arrived this weekend. Once again, pretty amazed how quickly Rock Auto delivered. Going to try to get this done next weekend.
 

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