I have a 1994 k1500 with a 4.3v6 and 193,000 miles on it. My gas mileage is constantly around 9-10 mpg and I need to increase it. I put 285/75 mud terrains on the truck, and it did not decrease the mileage, so I know tires are not my problem. In the last month I had the timing reset, new plugs, wires, cap, rotor, tps, IAC. I also had a new fuel pump/sending unit installed 6 months ago, now the gas gauge reads about a 1/4 tank off. I checked the pressure at the fuel filter, and it is the same before and after it. I also just removed my cat and welded in a straight pipe. I was wondering if you guys had any other suggestions, or if it is just my 16-year old lead foot that is killing my mileage?

I would go ahead and change the O2 sensor. That helped alot on mine. They should be changed every 80kmi for best operation. My truck only had one, i beleive yours does too. mines a 92 with 5.0L v-8. also, you might want to have your alignment checked. Thats all i can think of right now.

I would go ahead and change the O2 sensor. That helped alot on mine. They should be changed every 80kmi for best operation. My truck only had one, i beleive yours does too. mines a 92 with 5.0L v-8. also, you might want to have your alignment checked. Thats all i can think of right now.

Thanks, I might try that. Arent those sensors expensive? Also, I was wondering how an alignment could improve gas mileage. I'm a 16 year old mechanic, and I'm learnin everyday. Any other ideas you guys have would be helpful. Thanks

Heres an example: If your tires, or even one are pointing inward or outward, the truck/car whatever, has to work that much harder to move the vehicle. I had an old buick that i just bought from my aunt. The car would go straight, but when you let off the gas the car would decelerate like you were tapping the brake. Got a 4 wheel alignment and it coasted like a dream. Mileage went up too. Something simple that is often overlooked. Also, the O2 sensor for my truck was $15 at NAPA for the premium one.

Agree with the O2 sensor. A bad one can richen up the air/fuel mixture considerably.

Oh forgot to mention the GM service manual says to replace O2 sensor at 60,000 miles as routine maintenance. I had a co-worker who got anywhere between 19 and 24 mpg with his 2WD 1992 Fullsize 1500 4.3 with 5 speed manual tranny. That's pretty good mileage for a fullsize truck. I have a Dodge Ram 1500 (2001 3.9 six cyl. with 5 speed manual) that gets an average of 18-20 mpg.

thanks, it looks like im going to try both of them. I was wondering, how much does a 4 wheel alignment usually cost? Also, have you guys found any tricks for the common broken gas gauge? I got a new sending unit/pump over the summer, and when I filled the truck up last week, the gauge went 1/4 inch past full, and now it's off. Thanks in advance

For electrical parts I have the best luck with OEM ACDelco parts. try www.gmpartsdirect.com for pretty decent prices. I ordered a wiper module for my old S-10 a few years ago and it got here in just 3 days. The fuel tank is so big on the fullsize trucks it's pretty hard to run out of gas if you keep track of the mileage and fill it up every week. Was the sending replaced with an OEM unit?

No, it was not a GM unit. The dealership did not have one in stock, so I got one from a local radiator shop. They warranty the parts for one year, but I have a hard time believing that it would go bad so fast. I was also wondering of something could have happened when I took my gauge cluster out to replace the lights. Is there some kind of re-set procedure to get the gauges back to normal. Any help would be great

You may also want to check to EGR valve.

Is there any way to test an EGR while it is on the truck?

Help anybody?

If it's vacuum controlled, hook a vacuum pump up to the EGR. If it works, it should kill the engine (or come very close) at idle. Unplug the IAC so it doesn't affect the "test"

Maybe I'll just replace the EGR, they cant be that expensive. Would running some fuel cleaner with higher octane do anything. I'm getting really fed up with this gas bill everyweek. 60 bucks to drive to freakin school and back. I'm welcome to any ideas