28 lbs. boost

[jag]

Buddy has a 2004 - 2500 Cummins that will not make more than 28 lbs. boost. Tried plugging the wastegate (turbo is a 64 - 68 - 14) tried 2 different boost foolers, & a 20 lb. pressure test for boost leaks. Still won't go past 28. The only thing that I can find is the his MAF sensor is just plugged in & hanging there. There is no air box. Also there are no codes. We checked the MAP sensor & it is clean & not setting any codes. He says it made more boost even with it not installed before. Any ideas what else it might be? It also has a old BD fueling box with 3 settings & they don't even make a difference. Fuel mileage is way down to.

He is getting tired of being waxed by 4 cylinders! 

[Me78569]

sounds like tuning is not doing much.  He is going to need more fuel as I am guessing his new turbo is putting enough CFM worth of air to make the tune happy and thus it is not fueling any harder.  

[jag]

I was just talking to him, & he mentioned that he had injectors put in 30,000 miles ago. I asked him what brand & if they were any bigger than stock. He said they were BD'S but didn't know what size. The shop that installed them is out of business, plus no part number on the invoice. So ends this hunt, but I have to agree with Me78569 being not enough fuel not knowing what they are.

Thank you  

Edited October 28, 2020 by jag
error in mileage

[Mopar1973Man]

BD fueling box needs to go. Replace that...

 

That turbo would be for about 150 to 200 HP injectors. Plus a Quadzilla then you might really light that turbo.

[Me78569]

@Mopar1973Man I wouldn't be doing that on a 3rd gen.   

 

 

Edited October 28, 2020 by Me78569

[Mopar1973Man]

Opps... Gotta pay attention.  Need coffee yet...

 

Still in all then swap the Quad for Smarty Touch. But the only problem its too complex for most people to even tune.