mdbreaux

Anyone with experience on an ls2 cam sensor problem please let me know what the heck. Car ran fine for weeks. Then ran fine at dyno. Then would not start cues no fuel or spark. Failed BAL test in bs3 - red ball not gray. Rpm noted correct while cranking. Read a bunch of forums and said cam sensor may not be sensing or may be sending signal at same time as crank signal. I use 24 wheel on crank. I loosened up cam sensor and jiggled it and left it loose and BAM! Fire right up. Ran fine for weeks then last night no start and huge backfire. Motor ok - thank god! Now afraid to attempt to start. Did not have laptop to check bs3 and run BAL test. Can't go down track with full boost and lose cam signal so can't do anything right now. John meany of bs3 told me air gap between sensor and wheel very important and with aftermarket cams it may be off and he has an external cam sensor setup for this issue. .?????? I wander if I can measure distance from sensor seating surface and if sufficient room sand down sensor to timing cover mating surface? Of course still scared to go wot with boost and lose signal. SUCKS. HELP. LOL

bww3588

iTrader: (49)

The Ls2 picks up the cam off the cam gear, not the cam itself. Couple of things to check. Check cam endplay. It's possible that it's pulling the gear too far away from the pickup. Also, did you use the correct retainer plate with the correct bolts? Your gear could be hitting the heads of the bolts if you used the old bolts with a new style plate and its sitting too close to the pickup. Also check that your cam sensor is fully seated and tight in the front cover.

dschmittie1

iTrader: (64)

Is your BS3 set up for an ls1 or ls2 note the the sensors are pinned differently between the 2.

mdbreaux

I am going to have to check this. It wsa set up for an LS1 then I changed the engine to an LS2 so it is possible it is wrong. Thanks for the suggestion because I am very new to BS3 and need the suggestions. As soon as the miserable rain stops down here in Louisiana I am going to pull the car out and start testing everything I am now aware of. (1) distance between sensor and cam reluctor wheel, (2) BS3 programming issues, (3) is cam and crank sending signal at exact same time, (4) is cam sensor signal advanced sufficiently (5 or more degrees), and (5) sensor or wire or plug issues. Any other ideas are greatly appreciated.

mdbreaux

Intermittent cam signal loss still occurring and preventing car from further tuning. And it is a bummer! Car starts and runs great 10+ times then out of nowhere will not start and may even backfire if attempted too much. I loosen cam sensor and move it around some and tighten it back down and car back to normal. However, even when "running fine" dyno shows blips of rpm loss. I am running a BS3 for LS1, an LS2 engine with a 24 tooth wheel, a correct two switch cam gear, and I checked cam signal and crank signal tom be about 11 to 11.5 degrees apart. My two outside cam sensor wres are switched via a LS1 to LS2 cam sensor extension and I even switched them back and that was worse. I am going to check the air gap between the sensor and gear, but do not have a reference range to compare it to. I changed the sensor to a 95 GTO LS2 one and same thing. Both old and new cam sensors are AC Delco - new one gray and old one tan. Other than checking air gap of sensor and cam gear, only other things I have seen people do is change sensor to different brands or possibly get an external BS3 24 crank wheel setup, but that is ridiculous - the only benefit I can see is to adjust crank reference angle.

mdbreaux

An update to my problem. I ended up sending my BS3 back to get a new circuit placed for an external BS3 24 tooth crank gear to mount on the outside of my ATI damper. I then make my own bracket to accommodate an external adjustable sensor also provided by BS3. I then got an adapter to mount an MSD crank sensor with an LED light on the back of it and I am having the current 180 degree raised camshaft gear trigger machined off and placing a supplied magnet into the cam gear after having a machine fit hole drilled in the exact place, which I believe to be 65 degrees BTDC LED light on and 55 degrees light off. I have everything apart - lifters removed, etc. so we can re-time the cam and engine and I have not yet installed this stuff yet, but plan on doing so shortly. I took a much needed mental and physical break from this car. I am sure everyone just runs an MSD distributor at this point, but for various fabrication reasons I did not want to change everything at this point. If anyone has done this before, please feel free to let me know in case I have questions. If you attempted it and it did not work for any reason or have any comments, please feel free. Although I am determined to do this because any major changes would be made along with dry a sump setup and different intake manifold. I am trying not to go that route without some track time on the car.