"Pro" shop did cam/lifters/etc. = Now long start issue

So I'm in the process of having a cam swap done at a fairly reputable shop in Kansas. But we are having a bit of trouble.
Back story: '07 5.3L 2wd Yukon with the dreaded DOD lifter failure at 129K. Went with a small torquer comp cam with Ls7 lifters matching pushrods and springs. Had to have new timing chain and new cam position sensor installed. I picked it up and had some issues with the low end rpm, we met back up and returned so it wouldn't die when braking. Drove a total of 100 miles probably and now we have a lifter tick... Had to leave it there and catch a bus home across the state. They are looking into the lifter noise that popped up on all these new parts. No big deal right? The problem is it has a hard fault of the cam position sensor failed after the new one is installed. They programed it to not flash the engine light on the dash and said it was probably wiring faulty somewhere... I never had this problem of a 5-7 second start cycle where it turns and turns and turns before it lights off and runs.
They said it's not in the tune as they ran it on a loaded Dyno, and after the low idle issue we returned it on the street with me driving.

Anybody have long start cycle problems after a cam swap... Or a fault that can't be cleared for the cam position sensor?
Thanks everyone!

Fuel pump? pressure at the rails been checked?

Should be fine, no problems before. I asked about the pres. Regulator ... tuner didn't think that was it. I will triple check to see what the value is.

The issue ( I think) is with the Cam position sensor having the fault and not being able to be cleared-even after a new sensor was installed. The shop is suggesting that it is electrical or wiring... I am saying this was never the case previously (and I know this for a fact) as I fought the evap codes prior to the lifter failing and never once in multiple code checks did the cam position sensor fault ever show up. So it cranks for 5-7 seconds before it starts... But as I stated I think the starting issue is because of the fault... What could they have missed on a cam and 3 bolt sprocket/ lifters/ springs / timing chain that would cause this fault, and not allow a cam position sensor fault to be cleared?

Timing not set correctly?


The wiring may need to be tested. Possible they pinched a wire or broke on reinstall?



From my understanding if it's not getting a good reading form the cam or crank sensor it won't fire at all. It will just turn over.

Low end is running good once we returned it and set the idle at 600rpm. Mid range is a little flat, but top end is strong... So I think for the cam it's tuned ok now. As for the sensor... It cranks and eventually fires after about 5-10 seconds of cranking... I doubt that the wiring is bad because it will fire off... But that's what they are trying to tell me... 🙄 I don't buy it... The have a cam position sensor fault and said it's fine it will just take more cranks... I am not really happy with that answer... It never had this problem before, and I seriously doubt that my factory keyless remote start function will work with that fault. I asked them again today to check fuel rail pressure at start, and to change out the cam position sensor with another one thinking it might have been bad out of the box.. dunno... Ball is in his court... we Shall see how much he is willing to stand behind his work

Patience is a virtue...always better to be a cool customer... So they took our advice and swapped out the cam pos sensor for the second time to a Ac Delco /GM unit... That fixed the long start issue and the start on the key fob works...
They ran the thing for days trying to recreate the lifter ticking - driving it in subdivisions, hiway driving, idleing. Couldn't get it to lifter knock...(or what it sounded like when I picked it up the first time) (could this have been detonation at idle instead?)
Unfortunately there is NOW a p0016 code that won't clear...which is a cam pos bank A in correlation to the crank pos. They cleaned connectors, checked voltages, tryed clearing the code, but won't clear... Runs fine though (as they say)
My thoughts are it needs a crank sensor or for it to be relearned? I don't know if HP tunners can do that or not (never used it)
Anybody travel this road before? Can a (and I hate to even ask this) dealer fix this after my DoD delete?

Tried calling first thing this morning with the idea of a relearn, stated I will be up on the next day to pick it up like we talked about all on a phone message... no reply through the day on if a relearn was performed. So I spoke with the calibration shop in Bonner Springs via messenger to try to confirm the relarn and trouble shoot other things it could be... asking if the crank sensor showed good outputs, good voltages etc... ANYWAY...I guess I was asking to many questions after yesterday's conversation of -- "I will take the thing even with the p0016 code"... The owner called rather agrivated with me explaining they have tested everything they can other than replacing the wire harness...(said I need to authorize a harness change if we wanted to try that...at this point I'm thinking -I don't think so - not after we here gave you the idea to swap the cam pos sensor again) Said they have spent more time on this DoD swap than any of the 100+ trucks/cars they have done and never had this issue... Said the local dealer suggested they change the wire harness.... My view point as a customer is that I never had this problem until they did the DoD delete... At this point ya can't make a horse drink... Soooo I'm going to pick it up with the "Pending" P0016 code still present 😒 I kinda feel not good about this and the cash it cost... I was quoted $3800 over the phone and after taxes and shop supplies it was $4400 when I got there the first time... I could have gotten a Jasper engine for cheaper with 100k warranty (but not a huge fan of those)

He did reassure me that they ran it a bunch, drove it less than 200 miles and no knocking present, the excessively long start issue was fixed by replacing the cam pos sensor again, (but with a GM sensor this time - and only after I suggested it after you guys here suggested it to me!)... Runs good, idles good, drives good, and dyno'd good... There were multiple case relearns performed and assured me that was not it...



Any constructive troubleshooting or helpful thoughts guys?



Not excited about accepting a vehicle with a pending code present...



Bad part of this is I'm just going to have to accept this work - as I already paid for it the first time I picked it up and before I knew it had problems... Plus they don't know what else to do other that trouble shoot /replace a wire harness

Hard choice to make. I would have it annotated on the billing that the issue hasn't been fixed. For the record swapping a harness isn't hard if you decide to do it yourself. The cost of a harness is a chuck of change though. $250-380 depending on where you get them.

I found a video to help if you want to try to swap out the cam sensor yourself
https://www.youtube.com/watch?v=sDyHBQHR4OM



It's quite possible that the harness got broken or pinched when they did the delete. To troubleshoot a harness is time consuming that's why shops will gladly swap one out then to troubleshoot. It may be even cheaper because of the labor time costs.


i would try to swap out the sensor myself.

Isnt there a conversion kit to remove displacement on demand?

Yes, From what I've seen it has:

New LS7 Lifters, Head gaskets & bolts, a cam plate and depending on the kit, new seals, new cam, valley cover tray.

Plus tuning will be required to shut off the AFM in the tune. You can't just swap out the lifters because the DoD cam profile are different from cams without the AFM. That's why you'll need to factor in a new cam.

I may have missed it but what size cam are you running?

The cam spec on the receipt was 527/535 206/212

After I took it back the second time (when I pretty much chewed MO's butt over the phone for not completing the job and asking for my $$ back and that I would go away...
I gave them 1 more chance to get rid of the clackity clackity lifter knock noise that would show up when in gear at idle (like when sitting in line at a fast food restaurant) and after driving 30 minutes at 2000rpm...
They said the previous 2 times they couldn't duplicate the noise and can't fix it if they don't know what's wrong... They finally did as I asked them to and actually fixed the knock noise to some extent...here is what they said they did..
They drove it another 100miles (for a total of 330 miles and a full tank of gas -which they did not replace) They contacted me a full week after I left it there the 3rd time and said they were going to change all the Ls7 lifters again/new ls9 head gaskets again, and new gm head bolts again. Which took another full week.
This time, when I came back across the state for the 3rd time, it seemed to NOT knock with the clackity clackity lifter noise after driving it for 30 min.. but they also told me that they are now using 10w-40 regular oil and never to use Lucas additive!!! 🧐??? Said they thought the Lucas caused the original problem... (Which left me scratching my head) I know cammed engines are a little noisey so haven't thought much of the sewing machine noises... but I thought they were trying to cover up something by using that oil weight... And like a diligent mechanic, I went to change thier 10w-40 regular oil tonight at 500 miles (break in miles right?) back to my 5w30 synthetic and found some major issues.

1. Oil all over the transmission bell housing -brand new fresh drips - keep in mind this was a Mississippi truck and is spot less underneath -no grime, no rust, it looks pretty much brand new under there! So this definitely caught my attention! - then I found it.....
2. Oil plug not tight!!!! The plug was ready to spew! I mean it wasn't even finger tight guys!!!!!(found out I was about a qt low also after 500 miles)
3. Red rag fiber all over the oil plug magnet (it had metal in the rag fibers) why is there rag fibers in my oil pan!?!?! Why is there this much metal sludge??? It wasn't there before..
4. Changed the oil filter and cut it open... LOTS of long metal flakes (measuring from 0.05" to 0.10"!!!!!!!) and lots red rag fibers in the folds of the filter paper of the Wix 57060 filter after I cut it open...

So I messenger text LSX/MO on face book, said "umm think you have some explaining to do" with pics of the oil mess and rag fibers... He immediately replied and said: "There was no rag in my engine". Said that it was an old engine with 100k+ miles on it and it was dirty. (Inferring the oil was already there) And said I just wanted to find something to complain about and that I would never be happy. Then Said: I'm glad you engine is running great have a great weekend....then blocked me on Facebook... That's MO's customer service to someone that just wanted a properly built cammed motor...

So I would advise anyone that read this to stay away from LSX Kilr custom in Bonner Springs. Not to be trusted with your $4400 DoD delete. I did not have a good experience here.

things that also annoyed me.
1. Left lots of antifreeze in the core support after the first fix.
2. Had to travel across state 230 miles 3 times before finally picking up the vehicle and never once appologizing for the inconveniences.
3. I gave them permission to drive the vehicle to trouble shoot it, but 330miles total and a full tank of gas that they didn't offer to replace...

Seems like true "customer service" is a thing of the past these days.