cam/crank sensor
 

ok, so does anyone know how to test a cam or crank sensor (such as resistance, voltage in/out, etc)? i've been through a few searches but i haven't found anything solid on it. my problem is a hard to start and then surging idle (no codes) when it's warmed up. otherwise it runs pretty good.

i know i need new o2 sensors (although now it's not giving me that code either) but i wouldn't think that would be the hard to start problem.

any help would be appreciated

Yup. You need to use a GMM or o'scope to see what is exactly going on though. Ohmmeter is useless. Be careful when testing, they put out AC voltage - normally only 500-600mv when cranking, but I've seen some cars go up to 40v when running.

You could work-around by checking for spark or injector pulse when the difficulty normally occurs. If the crank sensor is bad neither pulse or spark will occur. I'm not saying that is the only thing that could cause the problem but it is the most common and, like I said, a work-around