Okay...so i've done the tuneup, fuel filter and begun changing fluids but the truck is definitely thirstier than it should be. Hooked up autotap and at idle, the ltft's are pegged at -14. Unplug the maf sensor and they start to dip and settle in the -7 to -8 range.

My understanding is ideally the ltft's should be close to zero for optimum performance.... so ....could the maf sensor perhaps be my culprit? Read that maf's are a common problem with these trucks.

What would be the best way to test it?

99 blazer zr2 auto 4x4.

thanks!

 

After doing some reading...i'm going to take some time on my days off this thursday and friday to clean the MAF and egr..see if that helps things out.

I'm getting around 16.5mpg right now which from what i've read isn't bad..but i'm pretty light on the pedal so i'm still expecting more.

Another thing that's odd... i've put about 4 tanks of gas in since i bought the truck and usually run it down to about the empty line on the guage...but i've never put more than 58liters(15gallons) in at the gas station. I thought it was a 19 gallon tank??? Is there really that much more room in there even after the light comes on and i go down to empty or could i have a smaller tank? (i suppose if the tank were ever replaced, a smaller one could be put in there.

 

You are not alone on the odd gas guages in Blazers. My guage reads empty after only 12-13 gallons being used. The fuel pump in the blazers uses gas to cool itself; so if you run the tank dry you are just frying your fuel pump. That is one reason the tank acts like it is empty when there is gas in it As far as gas mileage, you are correct in that you are in the normal range (check out the MPG poll), but yes cleaning those two parts can help your engine run better and increase your gas mileage some.

 

That's good info to know...thanks! I wondered why i'm only putting in 58 litres per fillup. My old 89 Jimmy could stuff 74 in easy.

I'll do the maf and egr this week and rescan the fuel trims to see if they're any different.