7.3l power, economy issue
 

i just bought a 2003 7.3l, it has 36s on it right now, i just put a custom intake, 4" downpipe to 5' exhaust and a edge juice with attitude program in, and the truck it gutless and a pig on fuel. it makes decent power with the programmer turned right up, but babying the truck I am lucky to get 11 mpg on any power level, there is little to no smoke unless the program is turned right up. at wot it makes 22lbs boost. I don't know what the hpop pressure should be or the injector pressure width should be, but a long time ago i had a 2001 stock with a superchip and it made way more smoke power and much better fuel economy. does anyone have any ideas? i have no codes coming up and no driveline issues that could be a contributer??

Any help would be greatly appreciated.

Is it a crew cab long bed? It's got 36" tires and I'm assuming a lift... It has an edge programmer... Yep.........

Seriously though... You might need to check for boost leaks with that low of boost at WOT... I would think it should be making high 20's...

I could have one yet. Ill have to pressure test the system, how far in can I crank the waste gate in before I need to worry about overboosting without head studs in yet? And ya it's lifted. Regular box cc, right now it's stuck as my daily driver and I know it's a pig but it shouldn't be that bad for only 36s?

just disconnect the wastegate,you will have a hard time going over 25 30lbs if you done have the zener mod done. I have 37's and get 20mpg hwy with my php 6 position tuner

check your up pipes mine are leaking now and im only buildgin about 15-16 lbs with a garret 38r right now because mine are leaking

2manytoyz...how the hell are you getting 20mpg with 37s...

I solved a fuel guzzling problem today.

About a year ago my fuel economy went from an average of 13.6l/100km to 19.8l/100km.
Thats a serious drop to 12mpg us. Another symptom was that the power seemed to kinda go flat on the top end. The engine sound seemed off as well. When the pedal was tromped on the on ramp to the higway there was not the usual grey/brown smoke.

I rooted through the diagnostics book yesterday and noticed that poor fuel economy was also a symptom of a lack of power. Interestingly its related to low fuel pressure not high as i would have expected given the amount of fuel i was using. I dunno how that works exactly.

I pondered it for a while and taking into account that at 311k km i was still on the original fuel filter so it seemed reasonable that it might be a problem given that it was way over due for a change. Fords $60.00 price tag for a fuel filter has left me less than enthusiastic about changing it out for years now. 13yrs. to be exact. ( I run a 2000 excursion with a 7.3 in it.) (Useless trivia>So if i had changed the filter out 1 per year, thats an $881.40 savings which probably pays for some of the fuel i used while figuring out the problem.)

So off to the parts store i go and i find an OEM for $60.00 and something from china for $29.95. The china job even has a new bowl cap. Carefull scruitiny indicates no reason to go with the OEM. So with nothing to loose i picked it up.

Disassembly revealed that the old fuel filter was broken.. yup broken. The bottom gromet was split in two pieces, top and bottom, and the metal pan had come off the bottom of the filter. And of course, lots of soft grit inside the bowl.

So i cleaned it all out, Even drained the bowl and everything. Put the new filter in along with that god forsaken jackass king sized "O" ring on the cap, which works great if you get it right side up. The new cap is much better than the OEM. Powered up the fuel pump and checked for leaks. About that time, i figured it prudent to close the drain given the sound of a waterfall going down the engine somewhere to the ground.

So, i fired up the beast and noted that the engine sound and start was much better.
Took it for a run down the high way after resetting the Liters/km indicator. It was a slow crawl from 99.99 down to 11.9L/100km but there it stayed and I expect that with a cold start and some city driving it will average out some where between 12 and 13 which is better than it's been for years. (Avg 13.6) Factory spec is 19mpg us.

It should be noted that there was greasy snow on the highway, I have soft snow tires on the excursion and the temperature was -12C.

So i think its problem solved for $30.00 bucks. Gotta love it. :jump: