Page 1 of 5 123 ... LastLast
Results 1 to 10 of 42

Thread: HELP: I am lost !

  1. #1
    Senior Member
    Join Date
    Oct 2005
    Posts
    175

    Question HELP: I am lost !

    A few days ago I completed the build of my LQ9. Bought the truck with bad motor, completely disassembled. Used to be operated on LPG, I removed that system, though.
    Damage was mainly on the intake valve seats, a worn cam bearing and a little wear
    on the rear cylinder walls as well as worn rings, causing significant blow-by (plenty of oil inside the intake manifold as well as fouled plugs).
    I built the motor with new pistons/rings, oil pump, cam (COMP 54-412-11) and used heads and intake off of another motor (LQ4) with 57k miles.
    I did NOT replace the timing chain, which seemed to have a lot of slop (0.5") and reused the lifters.

    When starting the engine you can hear some noise mostly on the passenger side (metallic ticking).
    I am not sure though, if the noise is related to the fact that the motor only runs on 5 cylinders or if there is something mechanically not sound.
    I did a log of the current status, which shows that the pass side O2 sensor does not react like the drivers side and the injector (bank2) is at approx. 50% of what the bank 1 is at.
    Would it be possible that due to a bad lifter (or several) the combustion chamber is not filled properly causing this?
    The plugs on the pass side are fouled black (but otherwise new - 15min runtime), while the one on the drivers side look like new.

    Things I have tried so far:
    - changed ignition coils + wires
    - used different fuel rail+injectors on pass side
    - swapped ECM from other vehicle
    - verified injectors (will spray fuel and do tick)
    - spark plugs will create a good spark

    Using the DVT control I switched the injectors....now here is the strange part:
    One time it is injectors 2,6,8 that will not cause any change next time it is 2,4,5,7 the
    yet another try 1,2,....
    Is there a remote possibility that the order of the injectors gets screwed up???


    If you have any further ideas what to do next, please let me know.
    All I can think of is to swap O2s from left to right, pull the head(s) and double check
    timing chain alignment.

    Log_0008.efi
    2005 RCSB 2500HD GMC Sierra DURAMAX LLY
    1955 Chevy Truck 1st series, being restored
    2002 Mercedes C270 CDI

  2. #2
    Joe (Moderator) joecar's Avatar
    Join Date
    Apr 2003
    Posts
    28,403

    Default

    Try swapping O2's and see what happens...

    Looking at your log, I see bank2 is getting too much fuel (HO2S21) and the PCM is trying to cut this back (IBPW2)...

    when you swap injectors and O2's, did bank2 look the same (about 700+ mV)...?
    Attached Thumbnails Attached Thumbnails Click image for larger version. 

Name:	X.png 
Views:	241 
Size:	91.0 KB 
ID:	8221  

  3. #3
    Senior Member
    Join Date
    Oct 2005
    Posts
    175

    Default

    Actually I swapped in the rail and injectors from the other motor....the O2 read the same, 700+mV.
    If you look at the injector opening, the bank2 is only half as long as the bank1 and still rich.....
    leads me to believe that I don't get enough air into the cylinder.
    2005 RCSB 2500HD GMC Sierra DURAMAX LLY
    1955 Chevy Truck 1st series, being restored
    2002 Mercedes C270 CDI

  4. #4
    Joe (Moderator) joecar's Avatar
    Join Date
    Apr 2003
    Posts
    28,403

    Default

    That sounds like what is happening... can you do a compression test...?

  5. #5
    Joe (Moderator) joecar's Avatar
    Join Date
    Apr 2003
    Posts
    28,403

    Default

    Can you tell if the noise on bank2 is from upper or lower...?

  6. #6
    Joe (Moderator) joecar's Avatar
    Join Date
    Apr 2003
    Posts
    28,403

    Default Sanity checks...

    COMP 54-412-11 is spec'd at 212/218 114 so it shouldn't cause PTV problems, right...?

    Dots lined up, right...?

    Pushrod length is preloading lifters to an acceptable range, right...?

    Rockers are torqued down correctly (both lobes on base circle), right...?

  7. #7
    Senior Member
    Join Date
    Oct 2005
    Posts
    175

    Default

    Tried a compression test today, had to find out though that I needed the hose with a valve to the pressure gauge (used the one from the leak-down tester).
    I did torque the rockers as directed turning the crank one cylinder at a time. Did not check pushrod length but I did observe the slight preload on the lifters.
    Dots lined up.....well I have thought about that, but wouldn't that cause the same issues on all cylinders? Did not check PTV clearance, if I pull the head I will, though.
    Everone recommends to install new lifters but how does a motor react to bad lifters? Is it even possible that a lifter will not pump up with sufficient oil pressure present?
    Could a lifter be worn to a point that oil pressure will not pump up the lifter? How much lift will I still get without being pumped up?
    I get about 40psi oil pressure, which should be fine. Is there any way I don't get the same oil pressure on the pass side?
    Assembly error??

    Thanks,
    Lennart
    2005 RCSB 2500HD GMC Sierra DURAMAX LLY
    1955 Chevy Truck 1st series, being restored
    2002 Mercedes C270 CDI

  8. #8
    Joe (Moderator) joecar's Avatar
    Join Date
    Apr 2003
    Posts
    28,403

    Default

    Remove valve covers, then with engine running you should see oil pumping out of pushrods onto rockers.

  9. #9
    Senior Member Chuck L.'s Avatar
    Join Date
    Feb 2006
    Posts
    184

    Default Water damage..

    How long did the injectors that U R using, sit B4 U started the engine?? How were they stored prior to you using them?
    A VERY COMMON problem that I find when cleaning injs is, those that have set for extended periods w/ gas in them, or ones that have been exposed to open air w/ fuel left in them, will not work. I find them stuck shut,[no flow at all], slow to react to pulse command, and have a poor pattern.
    Many sets I clean, are out of engines from the local junk yard, and have the above problems.
    This is a foto of a 95# delphi inj that was still running, but had "issues". It, and it's 5 brothers are JUNK!
    Attached Thumbnails Attached Thumbnails Click image for larger version. 

Name:	Bobs 95s 002.jpg 
Views:	267 
Size:	538.0 KB 
ID:	8228  
    Last edited by Chuck L.; June 12th, 2010 at 08:37 AM. Reason: Add photo..
    Chuck L.
    CODY Motorsports
    Fuel Injector Service
    Madison, GA.
    706-342-3152
    770-265-5144 [C]

  10. #10
    Senior Member
    Join Date
    Oct 2005
    Posts
    175

    Default

    Chuck,
    this is an interesting thought, all injectors I ran were stored approx 12-15 months.
    I looked at the spray pattern of one rail, looked OK to me.... still could be waay off.
    I was able to see a mist cloud of approx 3-4" during cranking.

    //Lennart
    2005 RCSB 2500HD GMC Sierra DURAMAX LLY
    1955 Chevy Truck 1st series, being restored
    2002 Mercedes C270 CDI

Page 1 of 5 123 ... LastLast

Similar Threads

  1. new and lost
    By WARDEN in forum Vortec V6/V8 Specific
    Replies: 2
    Last Post: May 19th, 2008, 10:09 AM
  2. Need help PCM lost
    By ripmf666 in forum General (Diesel)
    Replies: 4
    Last Post: November 9th, 2007, 02:24 PM
  3. Lost in the wilderness (V1 -> V2)
    By critter in forum FlashScan V2
    Replies: 3
    Last Post: September 11th, 2007, 01:14 PM
  4. im so lost
    By dynarex in forum Duramax 06 LLY / 06+ LBZ & LMM
    Replies: 11
    Last Post: January 13th, 2007, 04:10 AM
  5. Ok I'm Lost
    By TLKSCHP in forum General
    Replies: 21
    Last Post: September 30th, 2006, 10:57 AM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •