I work 60 plus hours a week and am full time single dad.. I would not even have time to wheel this thing even if I wanted to.. Its never been off road and stay in show room clean shape all the time. My 315s are Goodyear Druatracs and have been perfect for me on this rig and severl others over the last few years, No issues there. My fluids were replace with all GM Brand to put it right back to factory specs. No after market garbage in my rig.

 

I threw out the old o2 sensors, but they made no difference after I changed them. Plugs look great, water pump seems to be working ok. Needle hovers just a slight bit over the middle and stay steady unless I am running the hell out of it on the freeway or hauling my small enclosed trailer (which is rare)

Light beer indeed. Geez

 

I ran the truck on the 315s for about two months before I got the PCM done. I had them set it for the correct tire size. I was getting about 260 miles out a tank pre PCM tune/speedo corrected.

Once I got the PCM tune done I was up to about 300 miles per tank, I did not have it tuned for performance. I am flat out stumped..

I am thinking I will finally have to bow down, tuck my tail and take her to an actual GM dealership to have her looked at.. I call them the stealerships.. I hate them and they never listen to guys that have all the aftermarket parts done.. I know they will flash the computer and eff it up so that I have to buy another PCM.

This is getting silly. Watching my trip meter tonight, I am on track to get maybe 190 or 200 out of this tank.. This is getting spendy.

 

Update, So I took the truck down to my buddies shop again to day. We hooked up the dynamic reader to it and let it sit for a about 1/2 hour. Temp stayed consistent at 205 degrees, Idle was perfect, maintained right around 625 rpm (+ or - 20 or so) air intake temp was around 81 and stayed the same, fuel trim levels were around 5. He also mentioned the fuel bank lean was "disabled" due to the PCM4less.

The only thing we could really find that was odd was the post-cat O2 Sensor was lazy. It was not giving us any codes, but would just holding at the same level the entire time, like it was not reading. The other o2 would bounce between 125 and 800 ever second or so. Talking the the senior mechanic on site he explained that the o2 Sensor SHOULD be bouncing all over the place this is how the pcm reads high and low levels or something to that affect.. He gave me reason but its to much techy talk for me to explain. But it made sense to me and the 5 mechanics looking under the hood.

Fuel pressure was spot on and he was not at all worried about the injectors being dirty or having to much build up. He recommended that I put in a post cat o2 sensor, run the tank to empty put a can of seafoam in it and run a tank or two through it. If this does not work he will do some more research on it and maybe do a dealer assist with it. We looked at allparts. (their shop manual on line with all vehicle and service bullitens on it) and could not really find anything specific for my issue on either the h3 or the Colorado.

So I will go from here and see how it goes. The crappy thing was the only post cat o2 sensor from Napa (Bosch brand) was in Atalanta and I am in Portland Oregon.. So I will have to wait til Tuesday to put in the o2.

I will keep you guys posted.

 

Any updates? Tks!!!

 

somebody siphoning ure gas!!??

years ago,guys at the mills in gary had to pass the time doing something devious.
a guy bought a new vw and was keeping exact records from day one, and mileage went up on a regular steady basis,higher than he dreamed. then the guys quit adding incrementally more gas each day!!, took a week break. then they reversed the process and siphoned a little more out each day.
i guess the guy got out of treatment and gradually recovered, sold the vw,etc

if those guys ever applied their super mental skills to making steel,we might steal be in the business!1

 

YES!!!! So about two weeks ago I did the ported throttle body and supersparkz from Supernation off of 355nation..(Web site for Colorados and Canyons) What a huge difference power(Throttle response) and idle.

My first tank I went up to 260 miles per tank vs. the 230 I have been getting. I am taking it on a road drip this weekend to the beach and plan on putting some miles on her.. So we shall see how she does on a roadtrip. So far the Ported Throttlebody has been the best upgrade I have done.. Better then the PCMtune fore sure.

And as far as somebody siphoning gas from me.. I doubt that.. My marked take home police car parks next to my hummer and everybody knows in my neighborhood to not mess with my ****.

 

If you don't mind, what did you spend on the ported throttle body? Very interested about how it turns out so please update us when you get back! Thanks!

 

I paid $255 for the ported throttle body and the supersparkz set.. You can google both and get his link off of 335nation.. Very nice guy to deal with. So far my power is amazing.

I will post up my fuel mileage gains next week when I get back.

 

So, back from the beach trip road trip weekend. Had a blast with lots of buds. If you have been following you know that I normally get about 230 miles out of a tank, using 92 super/10% ethonl fuel.

The tank prior to heading to the beach I got about 260 miles out of, same gas, same type of city driving, I went form about 11mpg to 13 mpg.

I did the road trip and got just over 300 miles out of a tank. mostly highway miles, but also some light to light driving once at the coast up and down PCH. So I got about 15mpg on my road trip..

Its much better then I was getting prior to the ported thorttle body and supersparkz. I was getting 230 miles weather road tripping or around town. I would say money well spent and the power gains were great!!!! Went over the mountain passes at 70-75 mph with no trouble.