DoD delete issues

[caseIH1988]

hello everyone! new to the forum. well I have a 2007 avalanche with the lc9 5.3 that I rebuilt do to massive oil consumption and poor compression. I did the dod stuff to it but have been dealing with a misfire that I just cant get rid of. multiple mechanics have looked at it with no solution and is really making a big hole in my wallet. here is a list of what's done

1. block honed .020 over and cylinders true of roundness.
2. new pistons and rings to match
3. new rebuilt heads went from 243 to 862. long story
4. new cam from scoggin dicky for dod delete
5. new knock, map,maf, crank and camshaft sensors
6. new pushrods regular length, lifters from vette with 20k 
7. new pcm with vin coded programed and dod deleted.
8. new cats and oxygen sensors pcv valve, coils, plugs and wires anddddd fuel pump and lines.
9. with all this being said im so fed up with this truck, seems to me when ever I fix something it runs ok but then quickly turn to a heavy misfire on almost all cylinders. seems to be getting worse. dod delete camshaft is 191/190  .457/.466  114 and the stock lc9 cam is 193/193   .482/ .482   116+2 any help is appreciated. thanks

[Indy Mike]

Might examine your spark plugs. If "sooty" , they may running to cool and causing a miss, a higher heat range plug might do the trick.

Another thing about spark plugs is the factory suggested gap range. The wider gap end of the range will cause a plug to run a little hotter and the narrower gap tends to run a little cooler.

BTW,  make sure there is no silicon grease on the exterior end of the electrode or in the metal connector in the rubber boot. However, the inner leading edge of the rubber portion of the boot should have good coating of the silicon grease which actually has insulating properties.

Reading a spark plug is rapidly becoming a lost art.

Did you ever determine the cause of the excessive oil consumption?

One other note, honing a hole 0.020 " larger will not result in a perfectly round hole. A competent machine shop will bore within 0.001" to 0.002" then crosshatch hone the last bit to remove tool marks and give a surface for the rings to adapt to.

Good Luck,

Indy Mike

[swathdiver]

3 hours ago, caseIH1988 said:

hello everyone! new to the forum. well I have a 2007 avalanche with the lc9 5.3 that I rebuilt do to massive oil consumption and poor compression. I did the dod stuff to it but have been dealing with a misfire that I just cant get rid of. multiple mechanics have looked at it with no solution and is really making a big hole in my wallet. here is a list of what's done

1. block honed .020 over and cylinders true of roundness.
2. new pistons and rings to match
3. new rebuilt heads went from 243 to 862. long story
4. new cam from scoggin dicky for dod delete
5. new knock, map,maf, crank and camshaft sensors
6. new pushrods regular length, lifters from vette with 20k 
7. new pcm with vin coded programed and dod deleted.
8. new cats and oxygen sensors pcv valve, coils, plugs and wires anddddd fuel pump and lines.
9. with all this being said im so fed up with this truck, seems to me when ever I fix something it runs ok but then quickly turn to a heavy misfire on almost all cylinders. seems to be getting worse. dod delete camshaft is 191/190  .457/.466  114 and the stock lc9 cam is 193/193   .482/ .482   116+2 any help is appreciated. thanks

That cam obviously is not the same, less power and might be the problem if it was not indexed correctly during installation.  You need to hook it up to a bi-directional scan tool and watch the timing events between the crank and cam sensors and such.  If you have to open up the engine, dump that camshaft for the one from an L33, same grind as ours but without AFM.

 

A Tech-2 would quickly pay for itself here, allowing you to graph sensors and see what's going on so you can accurately fix it.  Live on the Treasure Coast by chance?

[caseIH1988]

thanks guys for the responses. spark plugs are stock for the avalanche acdelco iridiums gap checked out good no soot. some lube on inner part of wires. 

I was talking to my mechanic and he said all sensors read out fine, also good fuel pressure and good spark. We are both thinking cam. don't get why they recommend this same size cam for all dod delete kits unless I'm wrong.  By indexed do you mean degreed? this is my first time building a ls engine. made sure cylinder 1 is at tdc then installed cam gears and proceeded to line up the dots like the building book recommended. I didn't use a degree wheel.  do you guys this this cam would be more similar with my stock one, 

202/207  .480  .477  116+2  is the +2 advance timing? also I took the engine apart with 170k on it with heavy smoke at start up and heavy oil use. when I took the heads off some plugs were crystalized white also on bottom of heads so bad headgasket to.

I live in Wisconsin lol. 

 

[CamGTP]

What calibration was put into the computer?

[caseIH1988]

It would be stock calibration for my vin. With lc9

[TXGREEK]

Have you started giving it any thought, maybe it’s time to get rid of it?


Sent from Above

[swathdiver]

47 minutes ago, caseIH1988 said:

It would be stock calibration for my vin. With lc9

The camshaft is wrong and they use it because they did not know back then what the actual grind was and that the L33 even existed. 

 

I see the problem now,  you turned off AFM but did not program the computer for non-AFM and or the computer is programmed for one cam grind while you have another.  You need to get the engine properly tuned and have them raise the idle slightly, about 30-50 rpms.

[caseIH1988]

many many times. I just keep figuring its something simple

[caseIH1988]

so get the l33 cam and get it on the dyno?

[caseIH1988]

would this cam kill my mpgs      202/207  .480  .477  116+2 its a towing cam more less

[CamGTP]

No, that would be fine.

 

The main problem is that the computer is not tuned to turn off the DoD/AFM. With the computer still thinking that that system is functional, you will get tons of error codes and misfires/poor running.

 

The changing of camshaft, non dod lifters, valley plate etc etc is only one part of the puzzle. An aftermarket tuner needs to go in and disabled the DoD function. It would probably run like normal even with the camshaft you installed, just needs a tune first.

[swathdiver]

22 minutes ago, caseIH1988 said:

would this cam kill my mpgs      202/207  .480  .477  116+2 its a towing cam more less

I would have the tuner work with what you have so you don't have to open up the motor again if all was installed correctly.

 

That is a nice, mild cam, to me, would work good.  Crane and Cam Motion also make low duration, low lift cams that do not require programming but that one is even more conservative.

[caseIH1988]

I had AMS out of Louisiana tune it out. It must be working cause before it was tuned out i tried the new pcm without the dod delete and got all of the dod error codes for all 4 cylinders..plugged it back in after they deleted it and ran fine no codes just misfires. Shouldnt matter that i went from 243 to 862 heads? Same cc size i think.

[CamGTP]

I guess we got mixed up when you said stock calibration, so at least it was tuned to have DoD off.