hey,

i have 2000 blazer LS w/ 112k miles. I just bought it 2 weeks ago. The gas gauge like to "flicker" / "go crazy" while it sits in idle. Now if i do drive it stays at 3/4 of a tank and when i come to complete stop it goes to 1/2. My Mechanic says to replace the whole cluster and my other friend say just replace the whole fuel pump system in the tank.
I will try to get a video of what it does.

any ideas?

 

It sounds like the fuel sending unit your going to have to drop the tank and pull the pump out. but before you do that clean the connections on top of the tank it might help.

 

Another option if you don't want to drop the tank is to fill up, then use the trip odometer to keep track of miles driven between tanks. I fill up every 250-300 miles just to be safe and not run the tank too low. If/when the fuel pump goes, replace the entire assembly. No sense in dropping the tank twice! But it's 99% not your cluster.

 

I'm inclined to agree with TBB to a point. Don't go much beyond 270- 290 miles,you may run out depending on the terrain you run,etc. Definitely plan the pump change when you know it is low-even 5 gallons can be a pain as a gallon weighs about 5 lbs.
As for cluster issue:you may still have one. My 97 gauge fluctuates as the turn signal flashes-regardless of fuel level! And the coolant temp gauge never works! I installed a mechanical temp gauge to monitor that,so I am just putting up with the fuel gauge issue. I think a prior owner messed up the "touch connections" to the cluster while doing a heater core change and this persons lack of knowledge also eliminated many fasteners
upon re-install that resulted in my deep dash rattle at certain rpms! Just some ideas for you! step66

 

well thank for ur thoughts, Im going to start planning to a nice a day to drop the tank and see what I find.

 

I Had this problem with my blazer I
I droped my tank and found my ground wire was cracking and shabby looking I cleaned it up new wire heat shrink and checked it
its all good now havent had the problem since

 

hey esty, where was the bad ground wire you found, ive had the tank down, fuel pump out cleaned sending unit and my gauge is still screwed, it seem ok in any drive gear but all over the place in park or neutral. i even took the ground wire off the rear crossmember and tried to clean it but that didnt work either. i hate this bouncing gauge

 

Esty-

How hard is it to drop tank?

 

Scarnick.. if you've never dropped a tank before it is NOT a one man job. It's hard enough to do when you know what to expect. 3 gals of gas in that tank is a lot harder to handle than 3 gals in a carry can.

https://blazerforum.com/forum/2nd-ge...s-fixed-63397/
Read down till you find part about removing tank.. from there on it's about typical of what to expect.
Pay close attention to what I did wrong and why.

This was probably the dozenth tank I've done over the years, and things were fresh from me having done my tbird a few months earlier.

 

If not the ground then it is probally a faulty fuel gauge sending unit.