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Thread: Poor MPG and Lacks power
01-27-2010, 08:07 PM #11
In the summer I tow a Crestliner 1850 Sportfish. Good size boat, and I expect to get bad mpg's. But most of the time the truck is running bare.
I do use regular gas. I get it at SA, Holiday or BP. The truck does idel smooth. No hick ups. There is hesitation when I punch it. Takes a short period of timefor the motor to "catch up" I guess you can say. When I go to start it, it lights right now.
I have been looking into a programmer but I just don't understand how it can loose it's programming.
I do have a Viper car alarm/starter installed on it. That wouldn't cause anything.
I needed to replaced the hubs for the ABS system to work again.Tim - Minnesota
1997 Chevy Silverado ext cab
Few things added, nothing special!
01-27-2010, 08:39 PM #12
my truck is an 06 fullsize 4x4 with 4.3L v6 and it gets around 16-19 just plain running and 21-23 if i actually put a full tank and drive the high way.....if that helps any
2002 Tahoe LT---------TINTED WINDOWS------------7" DUAL DVD INDASH
01-27-2010, 11:13 PM #13
Mine did to. My company truck is a 2004 - 4.3 full size and I beat the snott out of that truck. I speed every where I go. I keep that peddel to the floor and still get an average of 16+. Im looking at reprogramers but I don't how well I'm going to deal with the disappointment when it dosn't work.
I installed the K&N air filter and just topped of the tank. I"m now down to 8.6 MPG.
02-04-2010, 01:53 AM #14
My dad live's240 miles away in Northern Minnesota. Went there this weekend. Put old air filter back in but I wrapped duct tape around 1/3rd of filter reducing the amount of air flow thru the filter. This was to test my vacuum leak theory. Went 240 miles and only used 1/2 tank of gas. Im on the right track.
Caddiac, some of the stuff you listed was checked. I am looking for the vacuum leak. The tranny was replaced. I need the tranny checked for it's shift pionts. I think it shifts to soon. Coolent level, thermostat, brakes and fuel pressure have been checked or replaced. Cat was checked by testing back pressure. No black smoke when I rev the engine. I know there is no cat or underware in their, maybe a few beer bottels.
I want to thank everyone who posted replys. Your help has been pricless!!
02-04-2010, 05:45 AM #15ROTARYENGINEPETE
'07 GMC SIERRA SLT | Z71 | 4X4 | 5.3L FF
ROUGH COUNTRY 3" PREMIUM SUSPENSION LIFT + ADD-A-LEAF
18" ATX THUG WHEELS
33" NITTO TRAIL GRAPPLER TIRES
EBC SPORT ROTORS
EBC YELLOW STUFF BRAKE PADS
HELLA/VVME 4300K HID LOW BEAMS
HELLA BLACK MAGIC OFFROAD LIGHTS
ANZO USA PROJECTORS HEADLIGHTS
ANZO USA LED TAIL LIGHTS
K&N 63 SERIES INTAKE
MAGNAFLOW CATBACK D.O.S.I.F.T. EXHAUST
BULLYDOG TRIPLE DOG GT TUNER
OPTIMA RED TOP
YUKON 4.56 GEARS
MAG-HYTEC DIFF COVER
TRANSGO SHIFT KIT
Z-PACK 3-4 CLUTCH
REBUILT WARN XFER CASE
RUNCOOL HOOD LOUVERS
FULL WEATHERTECH VISORS/BUGSHIELDS
DEEZEE BLACK DIAMOND PLATE BED CAPS
BULLDOG LOCKING SPORT FUEL DOOR
DOOR MOLDINGS REMOVED
CUSTOM WIRE MESH GRILL
BUSHWACKER BOSS FENDER FLARES
CB THRU GLASS RADIO ANTENNA
5.5sec 0-60mph on pavement (5.2sec running E85), and a little less in 3 feet of muddy water
01-30-2012, 08:15 PM #16
- Join Date
- Jan 2012
- Knoxville TN
carbon build up is a mpg killer too, this is so easy that if it fixes it u will throw urself off the cliff. get some B-12 Carb and Choke Cleaner, Throttle Body Cleaner, same thing best i can tell. soke the TB down with it and watch it melt, open it up and spray down in intake real good. spray in direction of runners for best results. now start it up and let it burn that out, then with it at idle start spraying it into the throttle body again and keep it running and keep spraying. for bad cases u may have to do the step where its not running and spraying it down the runners again. then keep it running spray heavily as u can into the intake.
01-31-2012, 07:44 AM #17
I wouldnt worry about the tire size, yeah it will effect it slightly but if its still dropping that isnt the proble, your stock tire was 29,5 and your new size is 31.6 inches tall, like i said it will effect it but that is neglagable, were you getting the 20+ with the bigger tires before. You could just buy a hypertech programmer so that you can put in the correct tire size99 K1500 Suburban LT "THE BEAST"
Hypertech III, K&N, true dual
01-31-2012, 09:15 AM #18
I have had two trucks with the 4.3 in them one was a full size GMC and the other was a S10, i ran a glass pack in both of them and never had a issue with not enough back pressure. Tire size is a big factor in calculating gas mileage because it throws off your speedometer and your odometer as well. You could be getting a lot better gas mileage but because you are actually going farther than you truck thinks it is throwing you off. If you have a GPS like a Tom Tom or a Garmin i would try tracking your mileage through that and than compare it to what your trip meter says on the truck, and calculate your gas mileage using the GPS. You can also use the GPS to see how far off your speedometer is on your truck. On my truck i am running 35s and when my speedometer says 40 i am actually going 46, at 50 i am going 58. It is worth a try before you spend a bunch of money on a programmer or any more parts. These are just some ideas to try, im not sure if this is something you have already done but im just throwing them out there for ya, i hope they can help.
03-07-2012, 11:14 AM #19
I matched the Tripometer with the Odometer on several trips where I knew the exact milage. I have the factory tire size back on the truck and around the cities here we have signs that say "Your speed" and show what your current speed is and they match. I don't know what to do anymore. I will try to clean the TB and see if that helps.
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