mysterious cam timing issue I NEED HELP p0017 and a lot of unknown!!

[scotttttiiiie]

long story long...
I bought a apparently modified 06 cobalt lsj. seemed pretty stock upon inspection. factory intake seemed like exhaust and that was it. ran and drove great no CEL or anything. passed emissions no problem {MO} drove it for six months or so with zero issues. pulled the plugs and pulled a shit job heli coil out with cylinder 3. brought the head to the machine shop and told em to fix it. upon dismantle my tech noticed the exhaust cam sprocket had the alignment guides ground off the sprocket. weird but didn't think much of it. at the same time it was at the machine shop I told em to port the head and put some cams in it. {comp cams} got my car back together and it ran and drove fine. idle was a bit rough but never died just seemed to search for an idle. I ran it untuned at that point. probably for 3-4 months like that. found a local tuner and upon uploading a tune he realized I was throwing a p0017. he said i was lucky driving it like that for so long. flashed a stock tune back on it. at that point i did a bunch of research about that code and comp cams and it seemed they had an issue with aligning the hex in the exhaust cam, and after talking with a tech at comp cams and verifying my shit was right I decided to try and correct my cam timing issue by putting the old sprocket on with the cut off tabs and tweaking my camshaft to make my cam sensor happy. after a couple attempts I managed to get rid of the code and have decent acceleration from the motor and left it at that for six months or so. no CEL, no drivability issues. this is still on factory tune. I got a can tune from zzp and had some issues. they sent me a second tune and seemed to be ok. my WOT afr was a bit lean, but i just stayed out of it that hard. got my hands on a hp tuner set and decided it was time to try and make my cam timing right. I test drove a couple cobalt lsj's at a car auction and was really surprised by the pick up it had compared to mine and wanted to get my exhaust cam timed right. so I took the cam out, and adjusted the hex in the exhaust cam to my stock cam. got it 90% or better to the stock cam, and put it all back together. Am throwing the same code, p0017 and after i start it once it will not start again. I tried turning the code off and it didn't make a difference. At one point I put the old cams back in with a new exhaust cam sprocket, the one I put on with the comp cams and it did the exact same thing it did with the comp cams. like, a previous owner had the same issue and did what i did by adjusting the exhaust cam to make it happy. I have no previous history as far as head work goes. i was told by the tuner that the head that was on my car was a zzp head. ive done countless crank relearns and what not. I need some guidance. I know my mechanical timing is right. I know my cam sensor is installed correctly. aligned it to the dash on the sensor and put it right in. i even took the end cam cap off to make sure my shit was right. currently.. I am throwing a p0017 which is current, history and pending, then a p0340 and p0341 which I have never seen. checked my connection at the sensor and all is good. I could really use some insight on what the ecm does when it sees a timing error. what I can do with hptuners if I know mechanical timing is right. and my biggest question is what one of the previous owners did to make the pcm happy. I exhausted all resources trying to find past owners with zero luck. i can get ahold of the owner i bought it from but he didn't do any of the work to it.
what the fuck do I do now...

[cobaltssoverbooster]

did your machine shop deck it?
did they at least measure the head to check if its been decked in the past?
•Cylinder Head Height/Thickness - measured from cylinder head deck to the cam cover sealing surface
128.65 mm
5.06 in
IIRC Maximum deck before codes arise is .015"
LSJ engines are pretty picky about being decked as the head now sits lower and causes the chain to slack up. This seems to cause a lot of cam timing issues. Not saying the cam timing isnt bad because the camshaft has the reluctor in the wrong spot but decking should also be taken into consideration.
Have you purchased the equipment to check your cam timing correctly? (IE: Degree Wheel, Dial Indicator) If your stock cam didn't throw a code on the setup and a properly degree'd cam does throw a code then the reluctor wheel is in the wrong spot.

[scotttttiiiie]

Overboost I am not sure about the head height. They are a very well known local machine shop but I was unaware of asking these questions diving into this. As far as prior to cam install, zero drive-ability issues/codes. BUT since they had ground off the cam sprocket tabs I don't see how they would have accurately timing the exhaust camshaft. I ended up putting that sprocket (one without the tabs) back on and adjusted my camshaft until I made the cam sensor happy. (bad I know) I put the original cams back in with a new correct sprocket with the tabs still intact but was having the same issues I had with the comp cams. I'm almost positive I had set the cam sensor up correctly, as I did it about a million times. and if you take the last cap off the cam you can see clear as day if its in the correct spot. What I don't know is what the previous owner did to rectify the issue. Or if the stock cams were actually stock. I was told by a local tuner that the head was a zzp head. that he was familiar with the vehicle. He also said the car was tuned before he had redone the tune. once he realized I was throwing a p0017 he flashed it back to factory. I put both of the exhaust cams next to each other with a cam alignment plate and it was clear as day the hex was off. it was literally as far off as it could get being a hexagon in shape. Is there a fix to heads that have been decked over .015"? And can I just have the hex retimed somewhere? I've called some custom cam places without much luck. comp cams did give me some good info when I called them about this back when I was dealing with it originally, but they basically told me they had timed it right.

[cobaltssoverbooster]

the fix for over decked heads it to buy new ones unfortunately. after going through both information posts again i dont think that is your issue.
when you install the cam sensor are you aligning the hex drive mark with the housing mark and installing the sensor when cylinder #4 is on compression tdc.
its a sensitive step that can be easily jacked up after attaching the sensor housing to the cylinder head. you have to look in the port for the sensor and verify the alignments after installation.

[TCSS07]

like overbooster stated make sure cyl 4 is where it needs to be ... easy way to tell is there's a mark on the front cover which needs to be lined up with the balancer notch before you line up the cam sensor. I installed a set of zzp stage 3 cams from my stage 2 and after every like 15 starts or so my car set a p0017 and i know the timing is mechanically correct so i just disabled the code (probably not the greatest thing to do but im not going to deal with it) also i did notice that when i was trying to line up the cam sensor i had to move it a little to line to bolts up in the head so my guess the hex for my cam is off just a smidge ... didnt have this issue with stage 2 cams

[scotttttiiiie]

I timed my cam sensor a million times. I'm confident my cam sensor is/was lined up correctly. Its almost impossible to incorrectly line up the sensor if you remove the cam end cap. you can literally see it all lined up after inserting the hex before sliding it in fully. And also, I had my cam lobes exactly where they needed to be per zzp's website. exhaust cams just closing on cyl 4 and intake cams about to open on cyl 1. at top dead center. I just put my original cams back in hoping to get it on the road again until I have my hex in my comp cams properly lined up (found a guy with a jig that can align it and weld it in place) but the same thing happens when I put it all back together. I replaced my timing chain for shits n grins this most recent time. I replaced all the guides and tensioner about a year ago when I got myself in this mess. I tried to get ahold of all the previous owners to see why they had put a cam sprocket on with the teeth ground off to possibly get a direction to go in with this but that didn't go anywhere. The original cam (the one I just put back in was installed with the cam gear's teeth ground off. It never threw the code but the pcm had a tune on it which I never was able to look at. I'm so frustrated with this and have no clue where to go.

[TCSS07]

i ran into this with a regular cobalt 2.2l and came to the conclusion that the car (branded title) was welded on and it picked up some emf and was screwing with the signal variance between the ecm and cam sensor because i couldn't find an actual legit reason as to why it was setting the correlation code - timing was good, new cmp sensors and new oe camshafts, new ecm ... so the timing actually had to be off one tooth for the dtc to pass so the ecm thought it was in time/but was actually out of time

so the zzp cams with the alignment gears with correct timing sets the dtc ... what about oe cams with the alignment gears? same result

[scotttttiiiie]

i ran into this with a regular cobalt 2.2l and came to the conclusion that the car (branded title) was welded on and it picked up some emf and was screwing with the signal variance between the ecm and cam sensor because i couldn't find an actual legit reason as to why it was setting the correlation code - timing was good, new cmp sensors and new oe camshafts, new ecm ... so the timing actually had to be off one tooth for the dtc to pass so the ecm thought it was in time/but was actually out of time

so the zzp cams with the alignment gears with correct timing sets the dtc ... what about oe cams with the alignment gears? same result

Well that's kinda the fucked up thing, I'm not 100% the cams I took out were factory. The exhaust cam sprocket had the two tabs in the center ring ground off when we took everything apart. So unless they degree'd the cam in, they pretty much did what I did and how I got it back to normal running condition was to use the sprocket with no alignment tabs and adjust the cam little by little until it didn't throw the p0017. Cause basically as of right now, if I take it apart and put it back together, it'll start and run but once I shut it off it will not restart. And I am using the cams that I took out originally. I am in the process of getting some factory lsj cams from a guy from facebook cobalt group and going to see if that takes care of this. thats the only thing that can make sense to me other than the head being resurfaced pasted the allowable tolerance. Also, the after market cams are COMP, not ZZP. If these "new" cams don't do the trick then it has to be the deck height or I should never touch a wrench again cause I can't align the cam sensor to save my life. I've read a lot of stuff from various places that don't really add up or work in my situation. Like deleting the p0017. Or people driving with the code on.

[TCSS07]

zzp stated that cams from comp cams direct don't come with the hex correct or something and cant use the cam sensor i believe ... im sure your doing it fine i mean all you have do is set the engine mechanical timing and then line the cam sensor up (front cover off) - i always do it after i put the front cover on and line up the crank notch with the front cover line but both ways will work ... but yeah try to get some factory cams and good gears and give it another go ... also i have my zzp stage 2 cams for sale if for some reason that falls through - $250.00 with about 20k on them and the hex is correct ... the zzp stage 3 cams for me however were a c*nt hair off so every 15-20 starts it set the p0017 so i just deleted the dtc because i dont have any actual driveability issues and also i dont care lol

[scotttttiiiie]

Thanks for the info. I believe I found someone who can fix the hex for me with my comp cams. I found a cheap set of OE ones I plan I using for now. Just gotta get it back on the road. I will keep you in mind about the zzp cams. Almost said fuck it and bought new ones from them yesterday but I just couldn't get myself to spend 600 bucks on em. If the new lsj cams work, I wonder what the hell I had in my car in the first place.

[TCSS07]

yeah id be leaning towards incorrect cams for the vehicle you shouldn't have to grind off the line up tabs on the gear to make it work unless its the wrong cam - how was the car running when you got it running?

[scotttttiiiie]

yeah id be leaning towards incorrect cams for the vehicle you shouldn't have to grind off the line up tabs on the gear to make it work unless its the wrong cam - how was the car running when you got it running?

So i got my hands on a set of factory lsj cams and got her running. I had the code disabled but am going to upload a new tune and to bring back the p0017. but this is the first time I was able to start it more than once. Every other time it would run fine until it shut off and not start again. period. I drove it around all night last night with no issues. Well.. Higher idle than it should be but that will all be corrected. Thanks for all the info from everyone. Glad this is behind me.

[cobaltssoverbooster]

sad that almost 12 years later comp cant cut a damn hex on angle

[scotttttiiiie]

Tell me about it. I found a guy that supposedly can align it for me. With all the trouble I've had with them I'm unsure if I really want to dig back into it.