fuel knock?

[02bigstrokin]

after i installed my modded lbz cp3 pump and my mpi twins, now my motor sounds like a dang massey fergusen tractor. all balance rates are within spec, i keep a constant check on the oil level, there is no fuel in it. it gets louder when you put the truck in gear, and we were usiong a screwdriver to try and pin point the noisy area and the fuel rails are really loud. the passenger side one is noticably louder the the drivers. it runs good, smooth, what do you guys think could be the problem? injectors going bad?

 

[DuramaxPowered]

did you adjust rail pressure valve current to compesate for the new pump?

 

[02bigstrokin]

yeah table b1010. larry jewell helped me with that. it was loping real bad and surging at crusing speeds. its all smothed out now it just sounds like a tractor.

 

[2500HeavyDuty]

how about balance rates with the truck cold, when my truck is warmed up the rates are in spec. but when i first turn it on i got an injector sitting at -10 and another sitting at +8 at idle. odd aint it?

 

[02bigstrokin]

they are opposite of yours. cold they are very close to zero(last time i checked, which was last week and it was doing the same knocking) and then when warm one goes to -3 but the rest are around -1 or 1

 

[sweetdiesel]

Sounds like a excessive rail press? Even though you have adjusted the truck with b1010 ....What is the rail pressure at idle?

 

[2500HeavyDuty]

they are opposite of yours. cold they are very close to zero(last time i checked, which was last week and it was doing the same knocking) and then when warm one goes to -3 but the rest are around -1 or 1

it could be from that odd ball one causing problems. i had one odd ball one for a while but it would be in spec for the longest. when it did go out of spec it took 3 others injectors with it

what is ur rp at idle anyhoo

 

[bullfrogjohnson]

Lat time we checked the rail pressure was around 5-6k at idle

 

[02bigstrokin]

Sounds like a excessive rail press? Even though you have adjusted the truck with b1010 ....What is the rail pressure at idle?

5000 idle

 

[02bigstrokin]

also, its not like the truck just sounds like a tractor in park or idle in drive, its all the way up through the gears. its seems to be getting louder. had a powerstroke guy riding with me tonight and he said" man i didnt realize the duramax's were so damn loud and rattely!" this coming from a 7.3 driver! wtf

 

[02bigstrokin]

anyone got a plow? we can hook it behind my truck and go plow some fields!

 

[bullfrogjohnson]

We will figure this out Josh, no worries:hug: No need to compare your truck to a masey ferguson:rofl:

 

[LBZ]

Sounds to me like maybe you have a bunk CP3. If the pressure is in the normal range, injectors are reasonably balanced, and the noise seems to be coming from the rails, I think the CP3 is the only place left to look.

Possibly a sticky plunger? The gear pump on the CP3 maybe causing a little cavitation due to a little fuel starvation? Does the CP3 return fuel look bubbly?

 

[02bigstrokin]

i dont know what the fuel looks like in the return, but i think the injectors are bad. i got up this morning and checked the oil and its definatly got fuel in it. i did the paper towel test and it had a ring of white around the black dot in the center and the level was twice as high as it should have been. also my antifreeze level dropped also. isnt that also a sign of bad injectors? the cp3 pump came from rhall on here and supposedly only has 10k on it. ill check with him but i dont think that is the problem.