Camshaft Position Sensor Engine Code

[T Devil]

I have a 1994 bmw 530 that was having rough idle issues. I did the stomp test to get my trouble codes and got Lambda control 1 and 2, Oxygen sensors 1 and 2, and MAF. I have replaced both O2 sensors and my MAF, and replaced all intake manifold (http://forums.bimmerforums.com/forum/showthread.php?t=1845213#) gaskets including the throttle body housing gasket, and the pcv plate gasket. I have checked my spark plugs and injectors and they don't appear to be in bad shape. I have disconnected and reconnected my battery to clear any codes. My car is now back together and idles fine at low rpm (http://forums.bimmerforums.com/forum/showthread.php?t=1845213#), but struggles at higher rpm and now misfires and shows the check engine (http://forums.bimmerforums.com/forum/showthread.php?t=1845213#) light. When I press the gas pedal, the check engine light goes away, but then re-appears when I let off the pedal. When I do my stomp test now, I get the camshaft position sensor code and the MAF code again. Is it possible I have damaged the camshaft sensor during intake manifold gasket replacement, and could that throw other sensors? Any help would be appreciated as I have been banging my head on the wall because I am running out of ideas! Thanks in advance!

[djb2]

Lambda control errors rarely mean that an oxygen sensor is bad. Especially if both sensors are reporting problems.

The error means that the computer couldn't control the fuel quantity well enough to get a valid O2 reading. That often means an intake air leak or a fuel pressure problem, not that the sensor isn't working.

Does the misfire only happen under heavy load? If so, that suggest that the spark is finding an alternate path to ground through broken insulation. It happens because higher cylinder pressure requires higher voltage to create a spark. If the misfire happens at higher RPM independent of load, it suggests that a position sensor has a problem.

[T Devil]

Thanks for the reply, the misfire happens at low idle with no acceleration, and occurs more frequently when I give it gas. When I changed out the gaskets I didnt unplug the sensor end of the camshaft position sensor. Which is why i'm hesitant to think the sensor is bad. Is there any way to check the camshaft sensor to see if it is good?

[T Devil]

It seems that my intake manifold bolts aren't completely tight. I sprayed starting fluid down by the gaskets, and the engine increased rpm's and backfired several times. Anyone know the torque settings for a 1994 530?

[ross1]

It seems that my intake manifold bolts aren't completely tight. I sprayed starting fluid down by the gaskets, and the engine increased rpm's and backfired several times. Anyone know the torque settings for a 1994 530?


Rather than running down the bolts trying to seal a rock hard rubber gasket it should be replaced.
While you're at it the PCV plate at the manifold back can be done, also have a look at the seals where the water pipes are beneath the manifold as well as checking the knock sensors for cracks.
Sorry to make a laundry list for you but tightening the bolts probably won't work. Also a reminder that the manifold is plastic, 18 year old plastic so best not to play with fire.

[T Devil]

I appreciate the response, however I am not tightening onto an old gasket. I replaced the intake gaskets, pcv and throttle gaskets. I got misfires after putting the engine back together, so I checked for leaks with starting fluid and the engine revved up indicating an air leak. I am not sure if I torqued the bolts down enough as I didn't know the torque specs. I am afraid to put too much torque. I think its around 7 ft lbs. Any other thoughts on the misfire?

[janders211]

you clearly described an intake leak...those bolts can probably take as mich torque as you can put with an 8 inch ratchet.

[DUDMD]

M7/M8 studs take a lot more than 7 ft lbs to torque down. Try 15-20ft lbs
I use 9-10ft lbs on a m6 bolt/stud.
Also, make sure none of the gaskets fell out during intake manifold install, it happened to my brother before. Simple and easy fix.

[T Devil]

Thanks for the reply, turns out one of the gaskets did fall out. Got it fixed and now running smooth. I'm getting fast at tearing that thing out! Thanks again for the info and torque specs. I am using about 8 ft/lbs on m6 bolts. Seems to be sufficient.