JASON EVANS

4. 3 L Vortec 138000k this engine does not have a distributor it has a coil pack. replaced timing chain because it was time to do so not because the engine was running bad or because the chain had jumped or broke. Car was running great compression was good no problems before I began this process. So let us begin.... In the process of replacing the timing chain, crankshaft position sensor, camshaft position sensor, map sensor, water pump, thermostat, engine coolant temperature sensor and air intake sensor, the camshaft Sprocket was rotated independent of the crankshaft sprocket with the timing chain removed. Why you ask? Because I'm an idiot. In an effort to redeem myself for my faux pas of idiocy, I tried three times to get the timing chain reset correctly. It was my understanding that the number one piston should be at the top dead center and both valves on the number one cylinder should be closed. I tried that didn't seem to work sounded like the engine had no compression when I try to start it. Then somebody told me to set the intake valve on number one so that it's starts opening 20 degrees BEFORE the number one Piston reaches top dead center and the intake valves should be fully open just as the Piston begins its descent to bottom dead center. So I tried that and when I tried to start the engine it sounded like he was really trying hard to start up making a nice loping sound almost wanted to start and then puked out P0340 p0341 codes. Then somebody told me to set the number one piston at top dead center so that the indicator on the crankshaft gear is pointing up and then set the cam shaft so that the exhaust valve is just closing and the indicator on the camshaft sprocket is also pointing up. By up I mean both dots on cam and crank sprocket pointing to 12 o clock position and that too did not work he was popping and spitting through the throttle body and now it's throwing P0340 p0341 p0016 p0108 codes. WILL SOMEONE PLEASE HELP ME OUT WITH THIS BEFORE I PULL MY HAIR OUT AND STAB MYSELF IN THE EYES?! Thank you, disgruntled noob

oldchevy

The dots on the sprocket should be pointing at each other. The crank dot should be at 12 and the cam sprocket dot should be at 6.


https://www.autozone.com/repairguide...96b43f81b3c416

JASON EVANS

Thank you for your reply. I tried setting the sprockets with the dots pointing at each other with both valve closed on number one cylinder but it still will not start it almost started but just wouldn't do it. I'm wondering if maybe I was 90 degrees or 180 degrees off on the cam timing? I think I had it set so that the intake valve was just starting to open