Im a newbie!! Frank from texas. 07 mega 4x4 dually 5.9 cummins, fresh rebuild, arson kit cp3, rebuilt stock sticks, new tank pump, frame mounted 2micron filter, new map sensors, 63/68/14mm turbo, hamilton 210/188 cam, 160# springs, built 48re, new tps, bullydog gt usually ran on performance to help spool. Pop/miss at 20% throttle. Has done this forever. Even b4 rebuild. Have replaced everything and done everything i can think off. I am missing something tho. I am a field tech for caterpillar and this cummins has me stumbed. Also egts run high. 1000-1400 at cruising speeds. Love my truck but getting to my witts end on this and dont know what else to do. Oh and put a new ecm and updated flash program from dodge to see if it made any diff. None. AND truck only and has always since i have had it 12 to 13 mpg on highway and 11 to 12 city mpg. 5000# load to houston, 8to 9 mpg. HELP PLEASE!!!

Im sorry i wasnt more clear. The injectors were replaced before the engine needed the rebuild. Thats the only reason why it didnt have improved sticks. If i knew it was going to have to be rebuilt at the time the inj needed changing i would have but wishful thinking was to just replace stock with stock inj and drive it another 100-200k. So where would you recommend me purchasing a 50-100 hp set of sticks from? I dont want to use anyone around here. Seems like the quality isnt a high priority for shops around here. Just make a quick buck.

Efi live is definately coming in the very near future. Wanted to try to solve drivability prob before going to reprogramming. I know the efi will help with that also. Looks like i need to get one asap. Any suggestions as to the best deal on a flashscan??

Call erick brown at browns diesel and tell him whats going on. He is pretty good with this stuff and he is amazing with EFI live

Where is he located? I appreciate the info!!

Brownsdiesel.com. Out in california

Thank you!!

Is the pop constant as long as your at 20% throttle? If not how long does it last? Does it vary in duration and intensity? Is it the same at 1500 rpms as it is at 2500 rpms?

 

Is the 20% throttle based on an OBDII output number or your guess?

 

1000°-1400° EGT's at cruise? Something isn't right! Was it that way before the rebuild? What are they WOT?

 

How much boost? How much boost when it pops?

 

160# springs? That is VERY heavy for a 24V motor, did you line bore the cam journals for bushings? The Hamilton springs are 103#.

 

Coffman Customs is in Texas and deals in BBi Injectors, nothing beats them.

It is constant at 20% at any range as long as its under load. In park cant detect it.

20% per guage tuner

Temps not known before rebuild. Added egt guage during rebuild. If i set cruise at 85 instead of 75 temps run 900 to 1000.

46# boost wot, 14 to 18 during pop.

Cam is journaled. Thought josh told me they were 160s. Might have misunderstood.

My "sweet" spot cruising is 65-75mph. The EGT's in my truck are actually lower at this speed than at 60 or even 55mph!!!!  Sometimes running 68-70mph, which is 2k rpm +or-, I'm running 475-575* according to my Autometer. The boost at those speeds would be 3-7psi on my truck.

 

AH64ID is correct……………that's not right…………………I re-read the OP, and I missed that!!!   :banghead:

I would love to see my egt around there. Another reason that points to faulty injectors. I have no excessive smoke. Im burning clean. Haze at first but clears up quick. Was like that b4 rebuild tho too.

I was just saying though………………..my truck isn't normal for most 3rd gens………………..most don't see the mileage I can get from mine…………even towing.

Im jealous!! Lol. I believe when i can get this fuel issue solved and do some programming with efi live i believe my dormant monster will come alive.

As much as I have read about these trucks your problems still point to injectors in my opinion...........

Im with you tom. Im thinking of doing a set and a new cp3.

If you have the budget look into big bang injectors

I agree with  Tom,    you  replaced the injectors  first,  THEN   cooked off   2  cylinders....    and    I'm  guessing you are heading down the  same path again!

Just to clarify it's 20% TPS, not 20% engine load?

 

At various rpms 20% throttle can be a variety of fueling parameters with different duration, pressure, timing, etc.. so if it is injectors that doesn't make sense. I would expect an injector to have issues at a certain volume/pressure which to me it sounds like your not having.

 

I hope something is wrong with your pyro, if you went back with stock pistons (assuming you did since you have stock sticks) they are not very fond of EGT's.

 

Now that brings up another point, what pistons are in it? This needs to be verified, did the rebuilder use 03-04 pistons or 04.5-07 pistons. Nothing wrong with 03-04 pistons in a 04.5-07 as long as the nozzles match (this is what I run and its MUCH stronger and more efficient than the 04.5-07 piston).

Called the place i bought my kit from. They assured me it was for 07 5.9. I didnt check casting numbers during rebuild but visually looked as the stocks did. Had to go i cant remember 10 or 20 over to clean up walls but nothing else as far as dome or bowl top. All looked same.

Pyro goes thry bullydog gt. assumed it is right. Guess time to get some manual guages.

They are quite different visually, so you probably would have noticed.

What do your EGT's read at idle?

Do you have an IR thermometer you can see the temp of the manifold with?