Fuel gauge

I have a 02 Blazer and I believe the fuel gauge is not working properly. After I have gone only about 40 miles on a full tank of gas the gauge shows ¾ full. Can that be correct? In the owner’s manual it states that I am to have an 18-gallon fuel tank. With an average of 20 mpg on the highway it should go to ¼ tank at about 90 miles.

What could be the problem?

Thanks,
Bobby

02 old style Blazer or the new Trailblazer?

Hello,

I have the old style blazer. It is 4WD with the V6.

Thanks,
Bobby

Also, today the blazer was on empty and it only took 13 gallons to fill up the tank. The specifications table states that I have an 18 gallon tank for the four door.

thanks,
Bobby

Originally posted by sadlerb_98
Also, today the blazer was on empty and it only took 13 gallons to fill up the tank. The specifications table states that I have an 18 gallon tank for the four door.

thanks,
Bobby


The four doors all came with 18 Gallon fuel tanks.

It could be a lot of things causing the fuel level sensor to read innacuratley, anything from a bad connection at the sender to a stuck level sensor, or the PCM itself could be acting up.

GM techs will usually use a scan tool to see if what the PCM reads, and compare it with the gage on the dash, if they are different then they will go through a troubleshooting procedure for the fuel system.

Thanks John. I will get it looked at then. Good thing it is still under the warranty.

Thanks again,
Bobby

Hello,

Today I had the fuel gauge sending unit replaced at the chevy dealership. The fuel gauge still seems to be off. It still reads 3/4 tank after only 40 miles. Has anybody else seen this before. I will call the dealership back tomorrow and see what else they can do. Please offer any suggestions.

Thanks,
Bobby

Well, Again on dead empty it took 13 gallons to fill up the fuel tank. The chevy dealership replaced the fuel sending unit again. One of the service guys said he thinks the fuel tank could be a 13 or 15 gallon one instead of the 18 gallon one but didn't know how to verify which one I had. Any ideas on how I can verify I got the 18 gallon tank?

Thanks,
Bobby

I get the same problem, my tank will stick at 3/4 tank no matter how much fuel I have unless the tank is full. When I put the car in Drive the guage will bounce around and finally read correctly if it sits long enough, but as soon as I place the truck in Drive, the gauge will creep back up to 3/4 tank.
It sounds like an electrical problem to me.

Originally posted by RobP3
I get the same problem, my tank will stick at 3/4 tank no matter how much fuel I have unless the tank is full. When I put the car in Drive the guage will bounce around and finally read correctly if it sits long enough, but as soon as I place the truck in Drive, the gauge will creep back up to 3/4 tank.
It sounds like an electrical problem to me.

In park and neutral the gas gauge is only going off the sender any other gear the PCM buffers the gas gauge.

Thanks guys. After two trips to the dealer and two new sending units my gauge is still not correct. I am think I will ask the next dealer about replacing the PCM. Not sure though.

Thanks for the info,
Bobby

Originally posted by RobP3
I get the same problem, my tank will stick at 3/4 tank no matter how much fuel I have unless the tank is full. When I put the car in Drive the guage will bounce around and finally read correctly if it sits long enough, but as soon as I place the truck in Drive, the gauge will creep back up to 3/4 tank.
It sounds like an electrical problem to me.

Sorry, what I meant was when I have the car in Park or Neutral the gauge will bounce around and read correctly once the fuel is settled, until I place it in Drive or other gears, then it will stick at 3/4 tank.

What is the PCM, where is is located?

R

Hello,

Well, I ran the blazer almost bone dry. It took just under 17 gallons to fill it up and was at 335 on the trip meter. So, I am sure I have the correct fuel tank installed.

My gauge does not bounce around or any of that. It stays pretty stable but just gives an inaccurate reading. I rode around on empty for over 160 miles so I know something isn't right.

I am not sure where the PCM is located. Maybe John or somebody will know.

Thanks,
Bobby

I have a 95 jimmy and i too go about 50mi and show half a tank. my gauge show empty and take 11-12 gallons to fill up. it use to be empty and show 1/4 tank until i got sick of it and moved the needle. Keep me posted.

Hey all,

My local dealership called the GM tech guys about my Blazer. They were told by GM that the Blazers are now designed to have a four to five gallon fuel reserve when the gauge shows empty to prevent the fuel pump from becoming dry and burning out. So, to make a long story short my gauge is working as designed. Seems like they should design the fuel pump to be in a better position so it wouldn't dry out and burn the motor out.

Thanks,
Bobby

Anybody come across this yet at their shops? Just doesn't seem right to have that much of a reserve.

Thanks,
Bobby

Yes they have a 5 gallon reserve, been all over these for similiar problems. Went as far on one to empty the tank, went and got 1 gallon of gas, put in the tank. Drove to the station on the corner and filled it with 16.8 gallons. Customer still didnt believe so he drove it untill the "Low Fuel" light cam on, brought it in, I pulled the tank and filled up a 5 gallon gas can with the remainder of the fuel.

bowtiebandit,

Thanks for the reply. I believe you; I won't think twice about it anymore.

Have a safe weekend.

Bob:biggrin:

No problem.. you aren't the only one that has been concerned about it. My own Blazer has a DIC that shows mileage remaining in tank and has always been pretty acurate. Low fuel light will come on and the DIC says 86 miles remaining in the tank so I watch that instead.

i have a 94 chevy s-10 that basically does the same thing. i can drive 100 miles with out my gauge moving from the full mark, i drive another 150 and its on half mark, then i get only 50 miles on the last half

Anybody come across this yet at their shops? Just doesn't seem right to have that much of a reserve.

Thanks,
Bobby


My 4 door Blazer does the same thing. I fill it up, and by 40 - 50 miles it's on 3/4. I was starting to get upset about it because I thought my gas mileage was just very very poor. I't's good to know I'm not the only one, and now I can not worry about it.