Lly hard start and throwing codes

[smokinlmm]

I think I might have a couple differen problems but not sure so thought I would ask the people. I just bought a 05 6aod with 112k been stock all it's life I noticed it was kinda hard starting but once started it was ok. Then the other day I was haulin hay and it went to limp mode I had a guy read the codes and I got a p1093 and p1094 I know that they are low rail pressure codes. Also when it's runnin I shut it off the primer bubble is not hard I can pump 12-15 times before it gets hard again and when drivin at higher rpms (2500 and up) it will smoke black every once in a while. Any advice is much appreciated thanks for reading

 

[NC-smokinlmm]

Scan your injectors balance rates...

Nice handle by the way, I always wondered who beat me to it on here. Lol...

 

[dirty_max]

check to see if it is sucking air anywhere and you might want to shim the rail relief valve just to rule that out and keep it from being a problem

 

[RKTMech]

Hows the fuel filter and the fuel your putting in it?

 

[smokinlmm]

I just changed the filter and we farm and buy bulk fuel and run several other duramaxs out of that tank and no problems with them

 

[McRat]

Low rail pressure:

Fuel restriction.
Air leak into the feed side.
Weak Pressure Relief Valve.
Fuel Pressure Regulator sticking.
Hurt CP3 injection pump.
Bad pressure sending unit.

 

[05Duramaxx]

I have an 05 with 250k miles having similar issues. So far I have
- replaced the CP3
- replaced fuel filter
- replaced most of the rubber lines
- replaced the FPRV to a race plug
- replaced all glow plugs
And replaced the glow plug control module.

still hard starts, runs pretty good but definitely not what it used to be. No tunes or serious upgrades at this time. and injectors are all within tolerances of balance. Any ideas?

 

[gmduramax]

I have an 05 with 250k miles having similar issues. So far I have
- replaced the CP3
- replaced fuel filter
- replaced most of the rubber lines
- replaced the FPRV to a race plug
- replaced all glow plugs
And replaced the glow plug control module.

still hard starts, runs pretty good but definitely not what it used to be. No tunes or serious upgrades at this time. and injectors are all within tolerances of balance. Any ideas?

Are you able to log rail pressure while cranking?

 

[05Duramaxx]

Are you able to log rail pressure while cranking?

Not sure how to do that. I do have a CTS insight II. I can look into it and see what I can come up with