S52 Power Loss at 5500RPM

[E30Sleeper]

I just got my car back after my S52 swap. With a mods it made 237hp to the wheels. I only put premium in it due to the chip.

The engine is running well except that the check engine light comes on at around 5500 rpm. When it comes on the engine hesitates and all the top end kick is gone.

If you build the rpm slowly its ok, but at full throttle the light comes on and the power drops off.

Any thoughts?

My mechanic thinks it might be the knock sensor.

Here's a link to the dyno pull.

[E30BeemerLad]

Possibly a camshaft sensor

My M52 was doing this, you could feel it hesitating near the top end. Replaced the cam sensor and the difference was staggering.

In the UK they cost about £75 from BMW, not worth buying an aftermarket one as they can vary wildly in quality.

[E30Sleeper]

Thanks for the feedback. Is there any way to test it to make sure?

[DanThe]

This will be because the ECU is not seeing the vehicle speed

[E30Sleeper]

This will be because the ECU is not seeing the vehicle speed

Is the Cam Sensor responsible for this?

[ian332isport]

This will be because the ECU is not seeing the vehicle speed

Is the Cam Sensor responsible for this?

How would the cam sensor have any way of knowing how fast the car is travelling

You probably don't have the road speed signal from the back of the instrument cluster being sent to the ECU.

Ian.

[E30Sleeper]

I think you nailed the problem. I'm going to try and fix it this weekend.

Cheers!

[yetti24]

sorry to hi jack this thread i have a similar prob what colour is the wire from the back of the cluster and which wire does it connect to in the dme ? i am running e30 m3 clocks i have an old sheet telling me to connect a blk/wht wire to 2 pin green plug ! doesnt sound right to me, i wrote another thread and some zoners told me to try a different set of clocks which i am going to try at the weekend but i still want to use my e30 m3 clocks