06 silverdo poor fuel milage

[frustrated06]

I am frustrated and at the end of my rope.

i have a 06 silverado with a 5.3, 2x2

i changed the engine at 196322.

it is now at 313000.

I had the wonderful REP///reduced engine power syndrome come see me.

 

MANY trips to 2 dealerships later( they are my customers)

 

they have maybe finally fixed that issue only to have a new issue, now bad mileage.

 

the fix to the REP syndrome was to build a new wiring harness from the TPS to the fuse block.

 

butttttt

 

it now idles barely at 500 rpm and tries to die often but doesnt.

 

I called the service advisor I use, is a former mechanic, he says to change the plugs/wires.

 

NO codes at all. I have cleaned the MAS, cleaned the K&N filter.

 

i have spent nearly 2000 while guesses were made to the REP mess.

 

I am ready to sell the truck I love.

I am not willing for more dealerships throwing darts at it.

I can throw darts too LOL.

 

idea's are greatly appreciated

 

[007matman]

Maybe getting too much fuel? Have you tried cleaning the injectors? Throttle body cleaning? Mass air flow sensor? Almost sounds like it's running rich.

 

Sent from my VS987 using Tapatalk

[frustrated06]

i did clean the Mass air.

 

it just happened when i got it back after the reduced engine power repair.

 

it wasnt getting the bad mileage (odd low idle, and stutter)before the wiring harness was replaced.

 

perhaps it is just a coincidence oddity.

[O_J_Simpson]

A few things. What mileage are you getting and what are you expecting to get? Other thing, why are you using a dealership on an 11 year old truck? It is so old they don't get training on it and they don't carry so many parts for it now. Use a better qualified shop.

[frustrated06]

before it was getting 15.6 or so. now 12 ish

[It's Tim]

I have cleaned the MAS

 

How? Was it contaminated with oil from the air filter?

[frustrated06]

was suggested by the dealership. it wasnt dirty. cleaned with aerosol Berrymans