Going to change the fuel pump in my 2000 4dr blazer. I looked up the correct fuel pump which would be AC delco or Delphi. I decided to go with the AC delco because I can find it for 50 bucks cheaper then Delphi (which I understand they are manufactured the same just labeled ac delco or Delphi). My only question is their is a new superceeded part number for the ac delco pump. Does this mean that the new superceeded part is better or improved? The reason I ask is because my gas gauge goes crazy. I have found a pump with the old part number. I am just concerned that the old part number part will not fix my gauge. I want to give the gas gauge problem a good shot at repair by changing my bad fuel pump. Maybe the new superceeded part has an updated fuel sender that will correct my gas gauge?

Ac Delco

Original part # 25176789

Superceeded part # 19177220

 

The problem with your gauge is usually not in the assembly itself. If you look closely at the pictorials, you will see a 1x4 connector pigtail included which you connect to the existing harness replacing the factory 2x2 one which fails often. Usually on the pump power side. That's what happened to me.
No one reading this should buy the old part unless they also buy the replacement OE 2x2 pigtail and replace the original.

However it may be economical to do that as the old versions are usually on clearance.

Dont be fooled into not replacing that harness connector just because it works when you plug it in.

That means whichever pump you buyyou must replace the pigtail... Unless you LIKE dropping the tank, that is. But if you like dropping the tank, then just replace the OE pigtail and it will work fine until the pump fails.
Before you drop the tank.. FIRST THING - disconnect the front tank vent tube!!!

BTW: exactly HOW does your fuel gauge 'go crazy'?

 

when I start up my truck the gauge goes to full then later it will go to empty and the low fuel light will come on. It does this whenever it wants and never reads true.

Looking at the picture of the pump I am buying (old part number) it shows a 1x4 pigtail. Is this the pigtail I am looking for. I know to absolutely change it because even if it works the old one could be the problem.

 

Yep. If the pic shows a 1x4 pigtail included it's the new style pump and changing the conn and pump should fix the problem unless G 402 is hinky.
HOWEVER..
Look at this:
http://www.ebay.com/itm/New-OEM-Fuel...item27be1dc695
It's the old style for $140 {edited ..was 80}
Buy this and the pigtail for the old style for $6 and what's to worry for another 100K or so.
You might also need a rubber collar/seal. Alt silicon grease after you clean up the old one.
and probably a new retainer ring from dealer: $26.

 

Ebay listings are very tricky. Their are tons of interchange part numbers and brands written in the listings. On that last listing they list the brand as pierce? I will not try an aftermarket because I plow with this truck. I cant get stuck. AC delco/ delphi or nothing.

This is the old part number ac delco that I have been looking at the picture might be down but when it comes up it has a 1x4 pigtail. I hope I am chasing the right part number for a 2000 4 door blazer 4.3 with plastic tank?

NEW AC DELCO FUEL PUMP 98 05 BLAZER JIMMY MU85 MU1733 | eBay

 

Here's the one i got for mine, Comes with a new gasket for the pump to tank and a new pigtail with 1 x 4 connector.

DELPHI Part # FG0052 {#FG005211B1} Plastic Fuel Tank
4 Door; Module Code TCH

$258 on rockauto. You can do a google search for rockauto discount codes and get 5% off.

 

That was a good catch. The orig one from him was ACD but expired... I just clicked on new listing and didnt look at fine print.


this one looks good.

Key is this guy has 100% feedback

 

case closed

 

When you install the new pigtail, solder it to the vehicle harness using rosin core solder and use heat shrink tubing for insulation. DO NOT use the cheezy crimp connectors that come with the new pump. Crimp connectors should never be used on a vehicle.

Here's the lock ring, you might not need it but it's best to have it handy in case you do: Buy Airtex Fuel Pump Lock Ring LR3002 at Advance Auto Parts_____

As mentioned, lube the O ring before installing the pump into the tank to keep it from rolling. If it doesn't seal properly you'll get EVAP DTC's.

 

If he's got the plastic fuel tank that may not be the lock ring he needs. If it's the NE2 RPO tank the lock ring is only available at the dealer new.

Here's one i found on Ebay FUEL PUMP LOCK RING CHEVY S10 BLAZER JIMMY TRUCK SONOMA | eBay