Replaced cam sensor, now car won't start

[TriniTT]

Hey all, I was referred here to member rotorhed from bimmerforums. I have a '98 Z3 and I'm having some minor issues. It's running rough, feels very underpowered and sluggish and has been this way since I've owned it. It idles rough and doesn't run well until it hits roughly 3-4k rpms. Occasionally the engine will try to cut off while I'm accelerating, and will backfire when I give it gas but won't every fully cut off.

After some research, I determined it was a good candidate for a cam sensor replacement. My check engine light isn't on, so I wasn't sure if I needed to check codes or not. My new cam sensor arrived today. After installation, the car wouldn't crank at all. It would turn over, but would have a slight backfire and just wouldn't run.

I reinstalled the original cam sensor, and it fired right up; but it's still running rough. Any suggestions would be phenomenal. Thanks!

JonnieB

[Bluebimma]

Did you order the correct sensor, not for the m42? Was the contact for the original cal sensor full of metal shavings? If so, clean it and reinstall. You may also want to Check and/or replace the crank position sensor. There are a few vacuum hoses that run underneath the intake manifold, follow it to the T fitting and make sure the T isn't severed of broken. Replace all the rubber vac lines there, there aren't too many and autozone carries the correct sizing. Use maf cleaner and clean the sensor inside the maf, the throttle body, and possibly run some seamfoam through the intake to clean through disa. While the engine is running, unplug the maf to make sure the CEL works. If it works, pull the code and make sure it's only pullng maf and not others as well. Another issue could be your coolant temp sensor. It's dialed and your dme and cluster use different signals from it. If it has built up a tolerance it will cause poor performance, poor idle, and hard starts.

[TriniTT]

It was the sensor for the M44. The original contact had a few tiny shavings on it, but I cleaned them off and it's still bad. I went and had the codes run today and the cam sensor code was the only one on there. I cleared it out, ran the engine again and check codes again, and the cam sensor code popped back up.

I cleaned out the MAF pretty well when I did spark plugs and other similar maintenance about a week ago. I double checked all the vacuum lines too, and none have any major cracks or holes. Also, there are never hard starts. The car always cranks right up and runs fairly well, it's just sluggish and idles roughly.