MPG Problems 2k1 chevy silverado.. v6 4.3 automatic - The 1947 - Present Chevrolet & GMC Truck Message Board Network

chevy4ever · 09-16-2005, 01:38 AM

Im having problems with my silverado single cab v6 vortek 4.3. About a year ago when i got the truck.. i was getting 17/18 in city.. and like 20/22 on freeway.. Now a year later.. im getting like 10/12 in city and like 15 or so on freeway.. WHAT IS GOING ON... i have replaced fuel filter.. i have cleaned the KNN air filter.. i have kept up with oil changed.. i have used fuel injector cleaners.. used octane boosters once in a blew moon.. that stuff from lucas most of the time. The only thing i havnt done is changed plugs. A friend of mine thinks its a vacum leak.. but nothing visable.. and i cant hear anything.. Any ideas guys.? if not can you suggest a site with a forum for newer trucks?? thanks in advance..
Matt

Joe67 · 09-16-2005, 08:08 AM

How many miles on the plugs? I know they are rated to 100K, but that is BS, mine were toast at 80K.

When you cleaned the K&N filter, were you careful not to over oil it? Sometimes people do over oil it and the oil gets on the MAF sensor and throws things off. They end up cleaning the MAF (very carefully...).

Have you made any other changes like tire size, etc?

67ChevyRedneck · 10-04-2005, 11:52 AM

This thread is a little old, but you may want to try GM-Trucks.com if your still having the problem. They have helped me with my truck. Could be anything from plugs to a bad sensor, possibly an O2? A dirty MAF will do that too. Is your message center giving out any malfuntion reading?

_Dick_ · 10-09-2005, 06:47 AM

You might try for help here
http://forums.s-series.org/index.php

good luck most help i can give you

*72CSTC5* · 10-13-2005, 11:35 PM

Have you checked your distributor cap and make sure there is not any moisture in there. There is a service bulletin on these trucks where the a/c line against the firewall is too close to the cap and causes it to sweat inside the cap. Check that out.

***Josh*** · 10-13-2005, 11:42 PM

They actually recalled most of em for the distributor cap now, might check into that, you get a free cap n rotor and they put a sleeve over the ac.

Without being able to play with it I cant say for sure why the MPG problems, but i would get a fuel pressure gauge on it and make sure the fuel pressure regulator isn't leaking, or the injectors aren't leaking...

09-16-2005, 01:38 AM	#1
chevy4ever Registered User Join Date: Aug 2002 Location: Corpus Christi, Tx Posts: 156	MPG Problems 2k1 chevy silverado.. v6 4.3 automatic Im having problems with my silverado single cab v6 vortek 4.3. About a year ago when i got the truck.. i was getting 17/18 in city.. and like 20/22 on freeway.. Now a year later.. im getting like 10/12 in city and like 15 or so on freeway.. WHAT IS GOING ON... i have replaced fuel filter.. i have cleaned the KNN air filter.. i have kept up with oil changed.. i have used fuel injector cleaners.. used octane boosters once in a blew moon.. that stuff from lucas most of the time. The only thing i havnt done is changed plugs. A friend of mine thinks its a vacum leak.. but nothing visable.. and i cant hear anything.. Any ideas guys.? if not can you suggest a site with a forum for newer trucks?? thanks in advance.. Matt __________________ email is matthew.solar1984@gmail.com 1980 Malibu Classic 2door(sold) 8-( 2001 Silverado single cab 4.3 V6(stolen and the totalled) 1979 GMC sierra swb stepside 350(sold) 1990 chevy suburban 4x4 350 2001 tahoe 4x4 2001 suburban 4x4

09-16-2005, 08:08 AM	#2
Joe67 67 is sold Join Date: Apr 2001 Location: Troy, Michigan Posts: 6,738	How many miles on the plugs? I know they are rated to 100K, but that is BS, mine were toast at 80K. When you cleaned the K&N filter, were you careful not to over oil it? Sometimes people do over oil it and the oil gets on the MAF sensor and throws things off. They end up cleaning the MAF (very carefully...). Have you made any other changes like tire size, etc? __________________ Joe - Formerly 67c10step ------------------------------- 1967 Chevy Stepside - ECE 4/6, fuelcell, 5lug - SOLD gr8lakes - My ebay auctions Click here to order forum apparel :: Click here to become a subscribing member

10-04-2005, 11:52 AM	#3
67ChevyRedneck Hittin E-Z Street on Mud Tires Join Date: Nov 2004 Location: Greenville, SC Posts: 23,090	This thread is a little old, but you may want to try GM-Trucks.com if your still having the problem. They have helped me with my truck. Could be anything from plugs to a bad sensor, possibly an O2? A dirty MAF will do that too. Is your message center giving out any malfuntion reading? __________________ Jesse James 1967 C10 SWB Stepside: 350/700R4/3.73 1965 Ford Mustang: 289/T5-5spd/3.25 Trac-Loc 1968 Pontiac Firebird: Project Fire Chicken! 2015 Silverado Double Cab 5.3L Z71 2001 Jeep Wrangler Sport 4.0L 5spd 2020 Chevrolet Equinox Premium 2.0L Turbo 2011 Mustang V6 ~ Wife's ride American Born, Country by the Grace of God 1967 CST Shop Truck Rebuild! My 1967 C-10 Build Thread My Vintage Air A/C Install Project "On a Dime" Trying my hand at Home Renovation! 1965 Mustang Modifications!

10-13-2005, 11:42 PM	#6
*Josh* He's got mean nasty FANGS! Join Date: Dec 1999 Location: Rockwell, NC Posts: 6,504	They actually recalled most of em for the distributor cap now, might check into that, you get a free cap n rotor and they put a sleeve over the ac. Without being able to play with it I cant say for sure why the MPG problems, but i would get a fuel pressure gauge on it and make sure the fuel pressure regulator isn't leaking, or the injectors aren't leaking... __________________ 2004 K2500 Burb 1999 C3500 1985 Cutlass Supreme 1969 C-10 1967 C-10 Panel josh@67-72chevytrucks.com

10-09-2005, 06:47 AM	#4
_Dick_ PROUD TO BE A MEMBER Join Date: Sep 2005 Location: Jax Florida Posts: 234	You might try for help here http://forums.s-series.org/index.php good luck most help i can give you

10-13-2005, 11:35 PM	#5
72CSTC5 Account Suspended Join Date: Nov 2004 Location: Deer Park, Tx. Posts: 2,524	Have you checked your distributor cap and make sure there is not any moisture in there. There is a service bulletin on these trucks where the a/c line against the firewall is too close to the cap and causes it to sweat inside the cap. Check that out.



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