99 Cummins low boost lack of power

[silverram99]

Recently I installed gauges in my truck with the suspicion that it had a low boost issue. After installing the gauge I have a peak of 16psi with my xzt+ module turned on. From the research I gathered it should be a minimum of 22 psi+. 

Last year I performed a leak test and didn’t discover any boost leaks, but I plan performing another test to make sure. The truck overall just doesn’t have the power it should. It never smokes, and the check engine light has come on in the past for a crank position sensor, but is off now. Just looking for suggestions on the low boost issue and lack of power. 

I was curious if the waste gate might be open, but figuring it does build boost maybe not? Any help is appreciated. 

[Evan]

My injectors were basically plugged. Truck had no power no boost crappy fuel mileage.

I'm now making about 28lbs of boost with 7x009 injectors. Plenty of power for me truck is quick and fun to drive. I'm now getting about 600 miles from a tank of fuel. My odometer only reads about .8 miles for every mile so I'm not sure what my mpg is.

 

I was told my vp44 eas dieng causing truck to not fuel like it should. Injectors where so carbines up you could see tracks where fuel was spraying through the carbon.

I did injectors om wot since they're cheaper than a vp44. Glad I did. Pumps been going strong ever since.

 

Good luck  that's just what I found with mine.

[silverram99]

Thank you for the reply, my plan In the near future is 7x.0085 dap injectors, I just want to fix any issue I have before, although the injectors being plugged has crossed my mind. Tonight I unplugged the xzt harnesses connectors and that brought some power back evidently it wasn’t working. 

[Evan]

You can pull the injectors and see how bad they are. Could even clean carbon off yourself with a wire brush and solvent.

It's not a horrible job to pull injectors. Just dont try to bend lines to clear injector tubes. 

[wil440]

Injectors always are sooted on the tips and clear tracks will be seen across the tips away from each hole, you have a problem if there isn't a clearish track away from each hole as thats a blocked hole, also touch the tips with nothing certainly not a wire brush, injection pressures are so high atomized fuel would cut through carbon on outside of tip like a hot knife through butter, if a hole is blocked it's more than likely blocked from the inside by metal particles

[Mopar1973Man]

When the pop pressure is roughly 4,500 PSI just o start the injector and the VP44 can reach up to somewhere around 20,000 PSI. 

 

The best stuff for cleaning injectors is a can of Carb Dip which will strip the carbon right off.

Edited August 16, 2018 by Mopar1973Man

[Evan]

Guys you should have seen my injectors.

[Dieselfuture]

45 minutes ago, Evan said:

Guys you should have seen my injectors.

I try take lots of pictures as no one seems to believe me  

CGI  

[Mopar1973Man]

13 hours ago, wil440 said:

if a hole is blocked it's more than likely blocked from the inside by metal particles

 

It can be blocked on the outside by ash. Typically caused by running waste engine oil, ATF or any lube oil with ash content. Hence 2 cycle oil most of it is ashless here in the states.

 

[wil440]

Never seen ash on injector like that but then again no one here adds oil of any kind to diesel. I think its rather odd that these trucks were designed and built in the usa and thats the major market but the diesel isn't really good enough