I used to fill my tank up at about 230 miles on the tank. Now the past few times I have filled up, its been closer to 170. Just a sudden drop and I don't know why. What should i check out first. I bet my air filter needs to be cleaned/recharged. Spark plugs were done maybe 2 oil changes ago. My fuel pump was replaced close to 2 years ago, but im not sure if they changed the fuel filter. Is that something they would do when you have a fuel pump replaced. Any ideas would be good. mods are in sig if your wondering. thanks!

 

Just a general tune up, and go from there.

 

How many miles are on the car? Take a look into the O2 Sensors (AC Delco ONLY) if they haven't been changed. Fuel filter wouldn't be a bad idea either.

 

Misfires and exhaust leaks before the O2 sensors can cause a sudden drop in fuel mileage.

 

I just put in new delcos when i did my headers. I also waited a little to put them in so the coating on the headers wouldnt mess them up.

Im waiting to get my brothers laptop so i can datalog it and see what its doing. But how do i change the fuel filter. I think i need to get that fuel line tool right?

 

Yeah, you'll need the quick disconnect tool to change the fuel filter. You can pick up a kit for $10-15 at any local parts store, or you can get just a 3/8" for our cars I believe (someone correct me if I'm wrong).

 

hey my blazer did the same exact thing and now the fuel gauge is stock on half a tank so i just use my trip to see when i got to fill up

 

I've never needed a quick disconnect tool for my filter.. But mine's a 95' and might be a bit different. It's bolted up on one end, and quick connect on the other, but all I've ever had to do to take it apart is just squeeze the tabs and it comes right apart.

 

You don't need a "quick disconnect" for the stock fuel filter. Its a GM fitting with a little nylon clip that you simply pinch to remove.

 

Shoe Box's Website is an LT1 owners Best Friend.

http://shbox.com/1/fuel_filter.html

 

He speaks the truth. You may implore the use of pliers to get enough pressure on the clip if its stubborn.

 

Too late, just bought one. Looks like im returning it sometime.