00 GMC 3500 Dually "Atlas Duce"

Thats a good looking truck man, I am interested in the mirrors you put on it. What brand are they and where did you get them from. Do those have the dual mirrors on each like the newer chevy's have? Thanks Tyler

I am a little discouraged with my truck right now, I made a trip to Corpus, it did terribly on fuel mileage.

Here is some data:
Miles |Gal |$/Gal |$ TTL |MPG
152716<-Starting Mileage
152915|22.254|$3.499|$77.87|8.94
153097|23.455|$3.499|$82.07|7.76
153218|23.480|$3.499|$82.16|5.15
153352|25.565|$3.399|$86.90|5.24
636|94.754|$3.474|329.00|6.77

This is for the entire trip putting my direct operating cost at $0.517 per mile. That is not very good. Considering in the capacity I am using this truck it is going to see roughly 30,000 miles a year, that adds up to $15,510.00 just for fuel.

What worries me is that the trailer I brought back weighed 4660 lbs, I had it weighed on a cat scale to be sure, that isn't exactly a heavy trailer, the truck was really struggling with it. I towed this same trailer with my friends dodge, the dodge yanked it down the street like nobody's business and did it getting about 15 mpg.

I think the issue is m distributor is wearing out, but I am not totally sure, the engine surges at low rpm then dies if you have it in gear and your foot on the brake, or you turn the wheels hard with out being on the accelerator.

Right now I am thinking my best bet may be swapping in my Cummins, but that is a lot of work. We will have to see. I am not sure I want to go through the money and expense though of putting a new distributor in the truck.

We will have to see, I am going to pop the cap and take a look at it and see what kind of shape the dizzy is in. if it seems tight I am not sure what else could be causing the issue.

you serioulsy need to get that truck to a shop and get it dyno tuned. carb rebuilt/ignition whatever, but that is bad mpgs..

Check if your coil giving good spark?

Btw, funny you mentioned firstgen bird. I have a black 95 Z28 and a 1969 Firebird.

Well tonight was fairly advantageous, I finally got around to breaking my timing light out of the box I brought back from Corpus, I checked the timing at idle, and the truck is set about 25

Wheres the pics!!!?

My 95 Z28 (6 speed) / 02 gsxr 600




My 69 Firebird, the wheels are photoshopped.
://i115.photobucket.com/albums/n291/GMHTP/Web/BW.jpg

My 90 C3500

Man those are some nice rides!

I had a passing thought earlier, I decided to open up the base config file for the Vortec 454 in HP tuners, What I found was kind of interesting.



In the Idle spark map (top) the timing below 85kPa is 25 degrees.

Last night with the timing light finding the timing at exactly 25

Tonight I decided to drive the truck to school with the MAP sensor unplugged, surprisingly the truck ran much better and had way more power than it did with it hooked up. I think I have found my problem. It shouldn't run better on the base line spark map.