I have often looked on HJ for reviews etc but never really looked in the back room. I have however been recommended to join up here to see if anyone can help with what seems like a slighly unusual problem with my E36, any suggestions/advice is much appreciated, here goes.

Car is a 1998 E36 323I with 120k on the clock, good history with alusil linered bores instead of the Nikasil liners found in older engines of this kind.

Symptoms:

1) Increased deceleration when in gear following the release of the throttle that continues until somewhere between 1000-2000rpm where suddenly the car feels like it has been "released" and it then decelerates like it should normally until the clutch is engaged. If the the car is put into neutral then there is no sign of the increased deceleration. This occurs in all gears whether at higher or low speed.

2) The car feels strangled and is lacking in torque through all gears and all the way through the rev range. In neutral the car revs up perfectly well. The intake bark is deeper and inline with what my old car sounded like when it had a blocked CAT.

3) MPG is down. I am currently unable to surpass 300 miles to a tank (tank is 60l last fill up I used 57l to do 290 odd miles. Average MPG on last fill up was 23mpg from a mixture of motorway and town driving with 2 cold starts a day. I confirm that MPG could be worse and that the main problems are the significant increased deceleration and reduced acceleration/lack of torque.

Things to note:

1. The car has been plugged in using full INPA software, no codes are shown.
2. Upon jacking up the car the front wheels spin completely freely. The back wheels will turn approximately 1.5 turns before stopping.
3. I have checked rubber hoses around the intake area and I cannot find and splits etc. The Crankcase breather valve has been changed and associated pipework cleaned of oily gunk.
4. CAT - car has had 3 different CAT's on it in my ownership, the original and 2x 328i catalytic converters that are a straight swap. The car behaved the same with both 328i CATS on and Im 90% sure it behaved the same when it had the 323i cats on. It is well documented that 328i Cats and back box are a straight swop and this would cause no problem and only an increase in performance due to their greater flow rate.
5. I have tried three different throttle position sensors, the original and two second hand items. Upon trying one of the second hand items the symptoms seemd to dissappear for a day or so. After this the symptoms permanently returned. Multimeter tests show the original and one of the second hand items to be operating ok. Subsequent swapping of the sensors around resulted in no difference.
6. I have tried running the car with the MAF unplugged and it stuttered horendously and anything other than very light throttle and the engine would try to die. Plugging it back in and the car drives normally only still with the above described symptoms.
7. Diff oil is sufficiently topped up. Gearbox oil is meant to be sealed for life but I think can see a weep from the filler plug and the box is covered in oil so I will try to change the oil as soon as possible. The gearbox is a little stiff to operate but all gears can still be relatively easily selected.
8. The aircon drivebelt is currenlty removed.
9. There is and always has been a slight wine from the front of the car. I changed the auxilary belt and this was reduced however I believe a bearing on the either one of the tensioners, the alternator or power steering pump is on its way out. This has not worsed over the last few thousand miles whereas the symptoms described above have.
10. Car has had new engine mounts replaced.
11. The car has had a new BMW oem crank sensor (following failure) within the last couple of months. This was very difficult to install. (sensor very very tight in the block used some lithium grease).

My current intentions:

1. Change gearbox oil.
2. Check earths
3. Check/clean crank sensor.

I am very stuck and cannot work out what is occuring. I ran my old healthy 323i back to back with this car for a short time and this only confirms something is wrong and I am not just looking for a problem that is not there. I like the car and want to get it fixed, If I cant sort it soon though then its going to get scrapped!

I must apologise for the huge first post but I wanted to give as much information as possible so people can make calculated suggestions. Any help is much appreciated.

Rory.