As this is my first post let me start by saying thank you to all of you who have contributed over the years providing so much information on Blazer repairs. Collectively you all have taken myself and my 1998 Blazer from 17k to now just passing 172K and going strong. I have learned it all from you guys from the plugs to the ball joints and everything in between.

Now for my problem. I also have a 2005 Trailblazer LT V6 4wd. Recently the fuel gauge has stopped indicating accurately and erradically moves from full to empty and everywhere in between with no apparent logic. It does this backing up, pulling foward, and simply cruising down the road. I am headed in the direction of the fuel sending unit(or fuel level sensor as Chevy calls it), located in the tank. I have never dropped a tank before, and am looking to see if you guys have any suggestions, perhaps a copy of the manual on this procedure, and any advice. Thanks again for all of you who have helped me along the road with my other Blazer through all your posts.

Ok... Few things here... Just a point of clarification. If it is a 2005 Trailblazer (GMT360/370 platform - ie. not S-series), then it would either have the 5.3L V8 or the 4.2L I6. If it is a 2005 S-series Blazer, then things are a bit different, but not drastically. Since you posted in the GMT360/370 platform, I'll take that cue and go forward with the procedure for the Trailblazer. For the fuel pump, the procedure is not different between the V8 and the I6 configurations, but it is different if it is a LWB or SWB (long/short wheel base).

Seeing as how you didn't mention that it is a LWB, I'll assume it is the SWB.

Check this out:
GMT360 Fuel Tank Removal (http://www.blazerforum.com/m_154037/mpage_1/key_/tm.htm#154037)

From there the sender is pretty easy to replace. You just have to loosen the retaining ring and remove the pump.

I hope my part number is wrong though... PN I show is 15077623 and lists for $366...http://www.blazerforum.com/upfiles/smiley/smiley21.gif Just for the gauge sender...??? WOW! Hope I never have to do this.

Now, maybe before doing all of this work, dump TWO (2) 20 gallon treatments of Chevron Techron Concentrate PLUS (make sure it's the plus) next time you fill up with fuel (before filling dump BOTH of them in, then fill the tank). See if that helps the condition. I use a bottle at every oil change on all of my vehicles. With the sulfur content of fuel now-a-days, its no wonder it doesn't happen more.

Kyle, thanks for the fast reply. I will definitely use the concentrate first. You were correct to assume the I6 and the SWB, as they are both right on. Thanks again for bailing me out, I look forward to driving this one as long as I have my 1998 Blazer. This forum has been a great help. I will post the end result on the concentrate or replacement of the sending unit, whichever is the case.

Kyle this could not have been a more timely post as my gas gage just started to act up. I just put in two cans of the Chevron Techron Concentrate Plus into my tank. Hopefully it will help. It is whole lot cheaper than taking in to a shop. So far I had to top my tank off and run a few errands and the gage at the full mark is correct right now.The last tank of gas the gage went way past the full mark so I am hoping that this is a good indication. I purchased the Techron concentrate Plus at O'Reily's auto parts it was about $10.99 for a 20 gal treatment. I then went to Wal-Mart and they had it for 5.67 but it was for a 12 gal. treatment. Thanks again for the recomendation.

Any updates?

I'm going to be replacing mine this weekend if the weather is bad, fishing comes first. anyway i have a 2005 trailblazer ls extended i6. in the earlier post it says that it's slightly different. how is it different. is it the same pump. removal procedures? thanks for the insight.

The procedure is a bit different with an EXT. Since posts are getting clipped at a character limit due to the problems with the server, you can't really even rely on the How-To I posted on the subject... Sorry.

If/When I get some time, I'll try to split things up to complete the How-To, referencing the differences between the SWB and LWB (Short and Long Wheel Base respectively) models.

Kyle:

Sorry for the delayed reply, I have been preoccupied with a new addition to the family. I did try repeatedly the recommendation of TWO (2) 20 gallon treatments of Chevron Techron Concentrate PLUS, and unfortunately this did not help. Due to the cost of the gauge sender, I will be putting this off until the spring / summer time frame. Thank you again as always for the advice. Best of luck to everyone else to ward off this potential problem by using the fuel addidtive before replacement becomes necessary.

Fuel additive will not fix a sending unit.Techron or any other additive isnt going to prolong a sending unit.Just be glad that your car is still new and it was easy to remove.
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bmw auto parts (http://www.carpartswholesale.com/cpw/bmw-car-parts.html)

kyleforum.com, your source for all answers kyle ;)

Fuel additive will not fix a sending unit.Techron or any other additive isnt going to prolong a sending unit.Just be glad that your car is still new and it was easy to remove.
Actually, Chevron Techron Fuel System Treatment Plus can remove harmful sulfur deposits from the sending unit and a filmer agent that can prevent the deposition of said sulfur... But thanks for dragging up a thread to state your opinion.

hahahha wow didnt even notice the date...whoooops

I had the exact same problem as mladsig on my 05 Trailblazer LT 2WD.
Erratic readings, and when the fuel level was below 1/2 full, the needle would sit on "Empty" with the amber light staying on. My local Chevy dealer wanted to replace the fuel pump for $750 !

After reading this forum, I went to Athens Chevrolet in Georgia, and they replaced the fuel level sensor (p/n 19177712 SEN KIT 3.107 $118.62) with labor $270.00 for a total of $398.86

This fixed the problem!! Thanks!

Thanks for the report. I am glad you were able to find the sender for less than I had originally posted it costing.

If you have not started using Chevron Techron Fuel System Treatment Plus at each oil change, start now!

I am having the same issues as everyone else here...I think I found the part needed from AC Delco:

http://www.rockauto.com/catalog/raframecatalog.php?catalog=343&partnum=SK1158&a=FR343-SK1158

Correct me if I'm wrong but this could solve the issue....just not sure I want to drop the tank myself :mad:

Would this part also be called a "Fuel Tank Pressure Sensor"? I found one at Autozone and wanted to make sure it was the right thing before I get it.

AC Delco SK1158 (replaces OE #88966954, #19178477, #88966954) is the fuel tank level sensor. Not the fuel tank pressure sensor.

Do you know what the part number is for a 2000 V6 Blazer with the TrailBlazer package?

Do you know what the part number is for a 2000 V6 Blazer with the TrailBlazer package?

it should be the same as any other 2nd gen blazer. also your tech questions belong in the 2nd gen section as you have a s-series blazer not a trailblazer.