L83 Won't Start after DOD Delete

[gofast321]

Hi everyone. I need some help. I have a 2015 L83 (gen v) swapped into my 1988 Suburban. The swap has worked great for the past 3 years (I dive it everyday). A few weeks ago I had a DOD/AFM lifter fail. I decided to replace the cam and lifters and install DOD plugs in the block. I reassembled everything today but now the truck will crank but not start. It doesn't even sound like it wants to try to start.

- Timing looks right. Crank dot at 12 o'clock and cam arrow at 6 o'clock
- Engine is getting fuel (plugs are wet)
- Engine is getting spark (pulled a plug and cranked the engine and could see spark)

Strangely there seems to be a lot of air blowing out of the intake manifold. Almost feels like timing is out 180 but I don't think thats possible on one of these engines correct?

I already had the DOD deactivated in the ECU when I originally did the swap? Would there be additional ECU tuning required?

Any guidance or help would be appreciated. I'm all out of ideas.


Thanks in advance.


Chad

[Joyridin]

So what cam and lifters did you install? The direct replacement for the DOD cam? Did you check the pushrod length? Could you have missed the pin on the camshaft when reinstalling the cam phaser on the camshaft? It is pretty common for this to happen.

If you put a different cam in besides the direct replacement non-DOD cam, you will have to have it tuned again.

[gofast321]

Hi Joyridin. Thanks for responding.

So I bought a DOD delete kit from Scoggin Dickey Parts. Here is a link to the kit: https://sdparts.com/i-24138746-l83-d...3-engines.html

The kit comes with a GM cam (part# 12672469) which is the direct replacement to remove DOD but keeps stock performance specs.

The kit also comes with LS7 lifters and the correct lifter trays.

My understanding from the kit is that with this combination you can reuse your stock pushrods which I did. I am going to call Scoggin Dickey today just to confirm.

I don't think I missed the the cam pin for the phaser because after I installed the phaser I did rotate the engine multiple times just to make sure the cam gear turned true and it looked good. Plus if I missed the pin I would have expected the alignment dots to no longer meet at the 12/6 position.

I have started tearing it down again today to see if I missed anything. I'm not terribly familiar with these engines and I'm really stumped on this one.

[Joyridin]

If you missed the pin, everything will still rotate like normal, but the cam will be out of alignment with the cam phaser. The dots will still be inline on the timing chain/gears.

Rotate the engine and set piston #1 at TDC. Both valves should be closed if you are on compression stroke. If not, the cam is off location.

[gofast321]

Interesting... in my head I assumed that the dots would have moved but I see what you mean. That will be the next thing I check today. Thanks!


Chad

[gofast321]

Joyridin, you nailed it. I took the timing gear off tonight and the cam gear clearly missed the dowel pin on the cam shaft. Thanks so much for the suggestion!

Any recommendation on how to ensure the the cam gear is properly seated on that pin when I reassemble?


Thanks,
Chad

[Joyridin]

I do not recall exactly what I did, but I think I slid the phaser on the cam without the chain and rotated to where the marks should line up. I then took a paint marker and marked the location of the cam on the block. I removed the phaser, put on the chain and installed everything while making sure the cam did not rotate.

I did mine while the engine was sitting in the chassis with no oil pan and no front clip. It was pretty open. Good luck if you are trying to do it with the pan and oil pump in place.

[gofast321]

One thing I did notice today was that the dowel pin in the new cam is half the length of the dowel pin in the stock cam I took out of the engine. I'm concerned that this might be part of my problem. I'm not sure there is enough dowel exposed to adequately engage the cam phaser. The stock cam had 4mm of the pin exposed while the new replacement cam only has 2mm exposed. I'm not sure what the minimum requirement would be but this has me worried.

I emailed the company I ordered the cam from to get their take.

(pictures attached)

[Joyridin]

That does seem to be pushed in a bit far. By the time you measure the chamfer on the pin, you are locating on about 1 mm.

[gofast321]

Thought I would put a bow on this thread...

Got the engine running again. Thanks so much to Joyridin for the help.

A word of caution... if you are using the GM #12672469 cam shaft to do your DOD delete in a L83 engine, look the cam over very carefully before you install it. I ordered 3 of these cams and all were defective before I got a good one. First one had a short dowel pin and two other ones had significant nicks in the journals. If you are doing a DOD delete, I would recommend buying a better cam. Melling just started producing a cam with a similar profile as the GM (Melling pn# MC1429). With the Melling or the GM cam you do the DOD delete without changing out your valve springs, push rods, etc.

Also if you are going to install the cam in the truck without dropping the oil pan, get a long bolt from the harware store with the same thread as the phaser. After you get the chain back on the cam phaser, use that long bolt to spin the cam around a few times so you can feel the dowel pin drop into the dowel hole on the phaser. Do this a few times so you can understand what that feels like and to ensure its properly aligned.