To get that discrepency in MPG, the injectors have to be delivering a lot more fuel than the ECM thinks they are. That is a good sign they are leaking or something is wrong with the nozzles.

 

I think that is one of the problems with modern diesel engines. There is no data for the computer to double check the combustion process. Gas engines have O2 sensors and misfire monitors to let the ECM know if the engine is actually doing what it thinks it is. Our ECMs can compensate for tempature and air density/MAP but they basically run in closed loop all the time. No real time fuel trim or mixture correction. I suspect that is why there are so many tuners available for diesels and not gas engines.

Sooner than we think, we may start to see engines, both gas and diesel, without any valvetrain components at all. Any gas engine would have to have direct cylinder, high pressure injection like a diesel. They would have no throttle plates. All this will be accomplished with electronic solenoid operated valves, instead of the entire valvetrain. Infinite cam profiles and valve timing for every situation. Cylinders could be shut off at any time as well. This should take a lot computer power to run this complex of a system but I believe I read a few years ago that Merecedes Benz already had running engines. Mostly just my opinions, Mixed with some BS maybe

 

I don't know if anyone has suggested checking for dragging brakes or front end alignment, you could have some chassis related issues. My rig is set for almost 0 toe in and will gain speed up to about 70 coasting in neutral down a 4.5% grade. You might want to do a coast check, just to eliminate the chassis.

jim b

 

well lets see, as in my sig, 35 inch tires, 410 gears, auto tranny ( culprit ) quad race set on 100 hp...... I would say that only one of these options could help my mpg. About 26k miles on the truck so break in has happened. No smoke to lead me to thinking over fed through the injectors, no fuel in oil, Purrs like an angry cat

 

My over head was dead on till i had the flash now it is reading higher by 1.8MPG
Lets talk about pilot shot a little, any one have a spare set of injectors that netted good MPG I can try, That way we can find out if it could be the injectors or not, That pilot shot thing makes sence to me.

I get a ping sound when Im on it light but if i lay on it that sound goes away.
Are they all this way or is that from a problem with mine?

 

hmm i have gotten 450miles out of a tank with my chip and where i live in florida there is alot of stop and go traffic, plus i've only got 17,000 miles on my truck (all of this is with out the fass installed)

 

There is an algorithm in the software that trims fueling per cylinder. I don't know why dealers can't access the algorithm while diagnosing injector problems. It would be wayyyy better than listening for a change in tone when cutting out a cylinder.

All F1 engines currently employ pneumatic valvetrains. You won't see it on truck diesel engines for the forseeable future. The only reason F1 has it is for the insane engine speeds they run (something like 20,000 rpm). They don't have valve springs with enough tension to keep the valves from floating.

Watch what you wish for on the O2 sensors. I don't want them on my truck, but I'm not at liberty to say why.

 

I wouldn't be so sure of that. A quick search of 2007 diesel emission standards came up with this quote:

For 2007, International Truck and Engine Corp. is following a technology path very different from its competitors, relying in part on its new camless engine technology.

This camless technology, says International, leverages electrohydraulic technology, first applied to its low-pressure common rail fuel system in 1994, by using electronics to control valve timing in place of a conventional mechanical camshaft and pushrod assembly. Expected benefits of International's camless engine technology include a 40% increase in torque at clutch engagement speeds for smoother acceleration and faster starts, and increased parts reliability and less noise because the rate of closing is controlled with hydraulic actuation and the valves compress gently.

Well, they are only on gas engines to keep the catalytic converter working effectively. So we can assume they are going to be installed on diesels soon.

 

There is alot of marketing in the first paragraph. Maybe I'm just old fasioned, but I'm skeptical of alot of that. Especially considering how durable their current electro-hydraulic injectors are (as in not very). In addition, I didn't think the HEUI is a real common rail system to begin with. Maybe SuperDuty can enlighten us there.

We'll see, but base on their current warranty situation I'm sure am surprised they want to leverage the HEUI system.