turning DOWN the ip

[1994Diesel]

will turning down my fuel about 3 flats help me get better mpgs?

currently i have it turned up 2 flats.

i also think my ip is dying because i have noticed a little more smoke(clean air filter), less mpgs since i bought it, and the ip seems to be a little wet with diesel.

 

[ameristar1]

Depending on the mileage you have on the truck, you may have to go through the pump and injectors if you haven't done so already. And the basic rule is that the more powerful you make a diesel, the better the mpg.

 

[1994Diesel]

ok, hmm, the more power the better the mpg?

i have gone through the injectors.

but does my ip show signs of kickn the bucket?

 

[ameristar1]

If the mileage is dropping and the throttle response isn't what it used to be, and if it hasn't been replaced in the time you have had the truck, then you should do the pump. Talk to Agnem about a Baby Moose or get his fuel injection guy to go through the pump you already have, if you can afford to down the truck. Or better still, get a core and send it to him.
The reason that the mpg goes up with a higher hp, but well tuned diesel is that it's not working as hard as a less powerful one. If you don't have to put your foot all the way to the floor to get the job done, you save fuel. A different fueling and timing curve in the pump that allows the engine to run more efficiently increases power and reduces fuel consumption. Diesels are good like that, they thrive on lean mixtures and the more boost that you can safely run the better. I think the factory ATS/Ford turbo system is low boost (7-8psi) while the 7.3PSD is in the 20 pound range (just as a comparison).

 

[Diesel JD]

You can run much better than 7-8 psi on a 7.3 factory turbo without breaking anything but good luck seeing anything close to that with the factory downpipe anywhere before WOT. Your timing has probably changed with adding the fresh injectors which could be reducing you economy. That may mean that you need to time the truck with the right tools or it could mean that you need to get a rebuilt pump. There is a specific one for the factory turbo, which is what you want unless you get one of Mel's Moose Pumps or a "hot" pump from another builder. You should be able to push 12-13 psi on a factory turbo IDI without blowing a gasket. How many miles on the old injector pump?

 

[1994Diesel]

Hey thank for the responses guys. I get what you are saying.

Well, i think there is about 130-150 thousand miles on the pump, the engine is not the original and the po replaced the engine.

I can push about some where in the range of 12-13psi actualy, just wish i had the ats down pipe.

how bad is it when you turbos compressor has couple small nicks in the blades?

 

[ameristar1]

The nicks won't affect boost, but if it breaks on you, you will not be a happy camper. New compressor wheels are not expensive. Just think about it this way, the turbo spins at over 50000 rpm, and because of the stress involved with spinning something that fast things stretch. Heat and centrifugal forces are a mother. Now lets say you are going up a hill, your boosting that 12-13psi and then compressor surge hits or you are on a long pull and the egt's are up; wherever the weakest link is, it's going to get exposed.
The truck you have sounds like it's a few steps away from being all good.

 

[icanfixall]

Most injection pumps last around 100,000 miles if they are well taken care of. The new fuels with very little lubrication in them will kill a pump faster than we like to think. Plus running a motor out of fuel kills a pump. The fuel being pump thru it acts as a coolant and lubricant so don't run so low than you starve the pump. BTW... The turbo is turning well past 120,000 rpm when working hard. The inlet wheel is aluminum and the exhaust wheel is inconel. Even drops of water hitting the aluminum wheel at that speed will ding it.

 

[Smokey73]

don't forget, Black smoke = raw, unburnt, unused fuel. You can tune the pump to the point that you're not pumping raw fuel into the air, but still have plenty of power

 

[Agnem]

don't forget, Black smoke = raw, unburnt, unused fuel. You can tune the pump to the point that you're not pumping raw fuel into the air, but still have plenty of power

In principle I agree with that statement, but take exception to the terms unburnt and unused. Unburned, and unused fuel would still be a liquid. While certainly wastefull and inefficient, that black smoke IS still creating SOME energy. It is just a lack of oxygen which prevents it's conversion to 100% heat. Where there is smoke, there is fire.

 

[13fcolt]

i thought unburned fuel was white smoke?

 

[1994Diesel]

what is a baby moose pump? Im guessing its a milder version of the moose pump.

 

[redneckaggie]

i believe that white smoke is lack of fuel, but i know that black smoke is unburnt fuel. just as mel said it is not "unburnt". it is partially burnt, meaning that you didnt get the full bang out of it. burning fuel is just like any other chemical reaction it requires a certain amount of oxygen and if that amount is not present the reaction is not complete

 

[redneckaggie]

the baby moose pump is a rebuild to stock specs not to "moose" specs