Intermittent Rough Acceleration


Scotland, Glasgow
BMW 323i (e36)
My car has an Eaton M62 supercharger on it and occasionally suffers from a hesitation, jerkiness when accelerating. For example, if I have been following someone and manage to get round them, it jerks and pops and the revs don't climb. If I release the throttle and press slowly, that sometimes clears it but the acceleration still feels sluggish. The MAF is located in the usual position before the throttle body and the SC is located on the A/C side of the engine. I have a BPV with the weakest spring in it, working range of around 0-12psi of boost, car making around 7psi.

I am going to move the MAF to the AC side and place it in the intake of the SC in order to create a draw through system rather than the current blow through one. Carried out compression test within the last year or so and engine is very healthy. Spark plugs are all fine and in the same condition across all 6 cylinders, minor fouling but not wet or obviously sooty.

There does seem to be a sort of rattling sound coming from the front of the engine, maybe a VANOS issue? Car has done 183,000 miles and I don't have any evidence that the VANOS has been looked at ever, is it very hard to repair/replace?

Think that's about everything I can think of, I might add to this if I remember anything else.


NOTE: Tried changing the TPS, idle went wonky and the problem remained so I'll rule that out thanks
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