NW-99SS

iTrader: (6)

Car: 99 Camaro SS Stock bottom end LS1.
Recent mods: Heads/cam/exhaust, removed ECU, sent to tuner for re-calibration for bigger injectors and H/C/I/E.
Parts: See sig...

Story: Completed my H/C/I/E install last fall. Installed recalibrated ECU, went to start car. A little hesitant to start at first, attributed to new fuel filter and mods. Did fire up immediately the second time. No rpm on factory gauges. Scan tool reads P0343 Cam position sensor high voltage. Clear SES, same tach issue. Third start, takes multiple attempts to start.

Do a little research, change the Cam position sensor and check my grounds on the back of the driver side head. New sensor installed, grounds good. Should have fired it up at this point, but winter set in and I left it until spring.

Fast forward to this spring. Car is hard to start, idles rough (could be baseline tune), and very rich. Still no rpm on factory gauges. Reset P0343 while idling, tach jumps to 950 rpm for a brief moment, then drops to 0 and SES comes back on with P0343. Car has maximum total run time of 1 hr since H/C/I/E install.

Question: Has anyone here done a crank re-learn to tune out this problem? I doubt my cam bolts are loose at this point and I remember using loctite on the cam bolts and torqueing to spec. I may however, forgot to use loctite on the retaining plate bolts, but they were certainly torqued to spec as well.

Also, anyone else had this issue? Could a sensor that worked fine before mods suddenly be crapped out as well as a brand new one?

I am going to try to re-torque my ECU connections tonight, see if it makes any difference. Next step will be to remove the intake again and the valley cover and see if the lifters are riding the center of the cam lobes or not. Any help/advice is appreciated!

NW-99SS

iTrader: (6)

Update:

Removed red and blue connectors to ECU, re-torqued and started car (battery was disconnected for connector removal and install). Car fired up within normal time frame, rpm gauge initially jumped to idle speed, but only for 0.5 seconds, then dropped to 0 again.

I removed the intake manifold and valley cover for lifter to cam lobe inspection. I found that the lifters are not sitting dead center on the cam lobes. It looks as though the cam is back too far in the block, forcing the lifters to ride close to the forward edge of the cam lobes. I would attribute this to loose cam bolts as the cam appears to far back in the block.

So, I will have to drain all my fluids, remove my water pump, crank pulley, and timing cover and see what I find. Will update when I get to that point. Was hoping for a computer fix, but this points clearly to a mechanical problem that I am to blame for.

Just when I thought the car was ready to go for the summer Oh well, a trip to the dealer for a new crank bolt, hopefully not too much trouble with the crank pulley and timing cover coming off. Shouldn't be down too long.

usafws6

iTrader: (10)

im having the exact same issue, ive done everything youve done and then some. retorque cam bolts ect. im stumped. i think the crank relearn might be the issue here.

NW-99SS

iTrader: (6)

Did you check where your lifters are sitting on the cam?

I just opened mine up today, cam bolts were tight and torqued. I'm running an SLP double roller timing chain and oil pump.

So, I am stumped...cam bolts are tight to spec yet lifters are riding the front edge of the cam lobes. What gives??

Also, does the cam being too far back in the block in this manner mean the cam position sensor won't read properly?

DPRock

iTrader: (9)

Any updates on this issue? I'm having the same problems.

mike13

iTrader: (27)

There was a factory issue back in 2003 where the cam bolts on Z06's weren't torqued and one of the symptoms was the cam sensor code. So yes that could cause the problem.

j_tizzle_84

iTrader: (6)

While you have it apart maybe take push rods out and spin motor over to get the lifters up then check the cam for excessive in and out play.not sure if there is a spec for this but should not move much. You didn't install the bearing for the timing gear behind can retainer plate? Correct?

joecar

summary: GenIII (CMP sensor at rear) P0343 = cam walking (loose sprocket/retainer bolts)

NW-99SS

iTrader: (6)

The motor has the factory cam bearings installed. I checked a few of my rebuild books, and cam play is supoosed to be less than .015" back and forth.

As stated, my cam bolts were tight and torqued properly. The timing gear was fully seated on the face of the cam. It appears as though my cam may be machined incorrectly (odd I know) but I cannot think of any other reason the lifters would be riding the front edge of the cam lobes unless the length of the cam is too short.

I am in the process of removing the cam and going to spec it against my factory one for length, etc. Then if short, I will contact the manufacturer for a replacement and make sure I spec it before install. Just haven't put in the time for the car lately as I have been busy with yard work, planting trees, etc (sucks getting old and taking care of an acreage!).

Hoping to sort this out before August, as I have missed almost half the season to drive the car again

NicD

iTrader: (7)

I've read somewhere online about a camshaft that had too large of a front snout which didn't allow the cam gear to seat properly effectively pushing back the camshaft. Sounds like it may be your problem as well.

NW-99SS

iTrader: (6)

Checked the cam snout, seems like my timing gear is seating fully. Either way, the cam shouldn't be able to go that far back in the block?? The play would be greater than .015" if that is the case. Once the cam is out I will have a closer look to make sure the timing gear is fully seated on the snout.