LBZ: AF Cam issue

[PSConvert]

So.... Needing some outside advice with this one.
Maybe someone has encountered this or can shed some unseen light.
I've been chasing this issue (after some others) for about a week. Maybe more.... I really want to hear this damn thing run again!


Engine is a full o-haul/build with a Socal AF cam and brand new tested and flowed S&S oversized injectors.
Currently it's in a no-start situation throwing P0202 and P0208 codes.


So as fun as this whole ordeal has been (not so much these last few weeks) and despite less than stellar directions from SoCal, I think I have the whole firing order swap ironed out.

First time around I swapped some pins in the 36 pin connector from the engine side of the harness and the others in the 24 pin from the ECM side. Ended up having to replace a couple female pins and then went back and set everything from one side of the harness (ECM side).

So as I understand it in a nutshell; You only need to switch injector connector (via the control wire) to the appropriate injector for that cylinder for the AF. Which side of the harness this happens from isn't important in reality so long as you swap 2/5, 3/8 and 6/7 and go from the factory order of 12784563 to the AF order of 15634278.

So laid out the firing orders look like this:

the factory cylinder layout
1357
2468

Cylinder layout with the AF swap (this is what its set to now)
1826
5473


I have verified the AF order numerous times with an ohm meter by going from each injector connector to the bails, from the bail to the ECM plug and from the ECM plug back to the injector connector.
Basically pick the injector you want to test, say #8, find the pin in the ecm connector and you should find signal at the injector connector at hole #3.
Inj #2 is found at hole #5, Inj #6 will be found in #7, so on and so on.
All of the connections are showing 0.5 Ohms when tested.

Despite all of this, I still get a P0202 and P0208 codes after cranking for few seconds and the engine will not run. It spits and tries, but won't take off.
i suspect it's because the 2&8 injectors are not firing with the DTCs triggered.

The real kicker is if injectors 2 and 8 are switched in the Alt firing order,
(so it would look like)
1286
5473
there are no DTCs. (happened amongst the confusion by accident)
Soon as I corrected the 2/8 mixup, the DTCs popped up again.

Other things I have checked/covered already:
- I checked all pins via pinout from GMUpfitter.
- I have set and reset the bails and all connectors multiple times.
- All connections have dialectic grease applied.
- All grounds are connected and good (0.5 ohm).
- Voltage is good while cranking (on battery charger).
- Cam and Crank sensors are both getting 5v reference.
- Cam signal coming back fluctuates between 4.99-0.4x while cranking.
- Crank signal goes from 5.01v static to 3.44v steady while cranking.
- Compression check shows 320 - 350 psi which is about right for 16.5:1 pistons. All but cyls 2&4 where checked because of the HS pipe is in. My gauge isn't holding max pressure so it's difficult to be more accurate right now.
- Injectors without DTCs are misting when the engine is turned over with the glow plugs out.
- Logs are showing 6-10psi oil pressure while cranking.
- Logs are showing around 500 rpm when cranking (140-170 when all injectors are disconnected).
- RP is 6-10k while cranking.
- ECM has been refreshed (full cal flash) with both the DSP5 tuning and back to stock. When stock tune is loaded truck cranks smoother and will fire but immediately dies.
- Only other DTCs are for the EGR and Grid heater (both went bye bye and are turned off in the tuning) and an IAT sensor high code. Nothing that would prevent starting though.
- Yes, I have an AF Cam. Least thats what the one SoCal sent and I installed is marked.

I have reached out to SoCal but they're only available via email this last week due to the holiday. They have gotten back to me but the person I've been communicating with is now also stumped. :joker:


So would my assumption is the P0202 and P0208 codes will keep the truck from starting. Am I correct?
What possible causes are there for these codes?
Any idea what could cause them to go away with the firing order incorrect but come back when its set properly? It's an electrical issue, that I am nearly sure about.



*Since originally posting this up on dieselplace last week (and not getting any useful replies) I have tried ice picking the connectors of the two troublesome injectors. No change.

Tonight I swapped the one of the "bad" injectors with a known good one. DTC did not go away. Also injectors both ohmed out at .4-.5 and both had carbon on the tips which shows me they both have had fire in the cylinders.

 

[clrussell]

Ok so I didn't read all of that.


Did you change injector wiring or the main engine harness pins for the af cam?

 

[PSConvert]

Harness pins at the bails

 

[clrussell]

Harness pins at the bails

Double checked I assume?

Kinda sounds like you have a connection issue or bad pin.

 

[PSConvert]

Checked multiple times in multiple ways from multiple points including ohm meter, ice picking and swapping injectors.
As all covered in the incredibly long first chapter above. lol

 

[TheDirty06]

This is probably completely stupid. But can't you change the firing order on an 06 with efi live? Might be a pain but might be worth a shot.

 

[PSConvert]

I just learned the other day you actually can use efilive to do the AF swap in the LBZ+.
Chase Fleece developed a base AF tune and it's been given to Empire, Socal, Kory willis and a few others from what I read.

Had I known this I would have asked for it from the get go. I'm actually a bit perturbed SoCal doesn't mention a peep about it if it's actually available.
But here I am and something isn't right that needs to be figured out. I don't see it going away even with swapping everything back. :banghead:

 

[Awenta]

The wiring way is fool proof. I wouldn't do it any other way. Tunes can get mixed up.


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[Stancedlb7]

HOLY COW!!! Not to trying to be a duche here. But who built the motor? What Im getting at is, did they check the cam? It would suck to get it all together and it not be an AF cam.

 

[PSConvert]

HOLY COW!!! Not to trying to be a duche here. But who built the motor? What Im getting at is, did they check the cam? It would suck to get it all together and it not be an AF cam.

I built it. :spit:
And yes its an AF cam. Unless SoCal mislabeled it. Which means on the box and on the end of the cam. lol

But either way the issue I'm chasing right now is electrical not hard parts.

 

[moparkxracer]

Check the connnecots at the injectors, had a p code like that ended up having to change out the connector at the injector. Did the ice pick trick but eventually the codes came back, make sure you didn't mess up the pins inside the connectors accidently.

We re pinned my harness at the bale connectors as well.

 

[ty_LBZ]

This may help ya

http://www.duramaxdiesels.com/forum/showthread.php?t=63409&highlight=af+cam

 

[PSConvert]

Check the connnecots at the injectors, had a p code like that ended up having to change out the connector at the injector. Did the ice pick trick but eventually the codes came back, make sure you didn't mess up the pins inside the connectors accidently.

We re pinned my harness at the bale connectors as well.

That was my thought so i ice picked the connectors. No change.
Also ohm traced all wiring and all specs out at .5 ohm from he ecm to the inj connectors.

I might just replace the connectors with new ones to completely eliminate them.

 

[PSConvert]

This may help ya

http://www.duramaxdiesels.com/forum/showthread.php?t=63409&highlight=af+cam

Thanks. I've read that thread and several others for insight but still keep coming up with nothing that helps with my specific issue.

The swap is correct but truck now throws dtcs and will not start

 

[Chevy1925]

i suggest if you are 100% confident in your wiring that you pull the valve covers and verify the compression stroke starting from cyl 1 follows the AF firing order. if it does, your problem is electronic/wiring.

Your post is kind of a hard read on what you did and how you have been diaging it (not really your fault as this can get confusing quick) but i feel you have moved too many wires or those new connections you had to make are not done right or making connection.

 

[Awenta]

Have you checked your grounds as a last resort?

Didn't Katie have a similar problem that ended up being the tcm?


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[PSConvert]

i suggest if you are 100% confident in your wiring that you pull the valve covers and verify the compression stroke starting from cyl 1 follows the AF firing order. if it does, your problem is electronic/wiring.

Your post is kind of a hard read on what you did and how you have been diaging it (not really your fault as this can get confusing quick) but i feel you have moved too many wires or those new connections you had to make are not done right or making connection.

You're right. This whole matter tends to be confusing to begin with and theres so much info here it admittedly makes it worse. Add in everything is new or has been touched.... it gets massive fast.

The main issue i'm trying to chase down now is the dtcs being thrown.
I'm down to replacing the inj pigtails (just ordered a set) and possibly the ecm after that. Everything (I can think of) in between is accounted for.

 

[PSConvert]

Have you checked your grounds as a last resort?

Didn't Katie have a similar problem that ended up being the tcm?


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Grounds have all been ohm tested and come back at .05 ohms. One of the first routes I went being the whole frame was blasted and painted along with everything else.

TCM be the cause?
That might have some merit. I also wired in a BT lockup box while everything was out. I had to disconnect it because it was locking the tq convertor while cranking the engine.

 

[Chevy1925]

You're right. This whole matter tends to be confusing to begin with and theres so much info here it admittedly makes it worse. Add in everything is new or has been touched.... it gets massive fast.

The main issue i'm trying to chase down now is the dtcs being thrown.
I'm down to replacing the inj pigtails (just ordered a set) and possibly the ecm after that. Everything (I can think of) in between is accounted for.

dont base this solely off the codes. It just means you have not done something right. What you should do is back trace EVERYTHING you touched and did that leads up to this point (minus tearing the engine down at this point). I like your trust in Socal to have marked and sent the correct cam but it does not hurt for you to double check it is correct as well to rule out the more unlikely possibilities s thats pretty much where we are at (you seem to have ruled out the "top of the list to check" ones). I also much rather prefer to diag everything i can before spending money on parts you may not need. all it does is empty your wallet.

Can you look at your connections and list off what wires and where you have them for the ones you moved? thats the only thing im not seeing in your list of what you did.

 

[PSConvert]

dont base this solely off the codes. It just means you have not done something right. What you should do is back trace EVERYTHING you touched and did that leads up to this point (minus tearing the engine down at this point). I like your trust in Socal to have marked and sent the correct cam but it does not hurt for you to double check it is correct as well to rule out the more unlikely possibilities s thats pretty much where we are at (you seem to have ruled out the "top of the list to check" ones). I also much rather prefer to diag everything i can before spending money on parts you may not need. all it does is empty your wallet.

That's the thing, I've back traced all of wiring in the bails and those in the swap several times now. They're in the correct positions per the swap and have been both visually confirmed and via tracing with the ohm meter.

Its not that i necessarily trust the cam is correct but I really have no choice. Then or now. They don't divulge any of the specs and it's in. lol
And the hard parts (cam) is entirely independent of the electrical issues I'm seeing.
Unless I'm missing something......

I'm with you. I'm not one to just throw parts at a problem. There's a specific case in there somewhere, its just a matter of finding it.