Missfire

[stuartevans]

I have a 325i Sport which has a missfire at low revs between 1500 and 3500 the car misses slightly and makes it uncomfortable at around 70mph.
I have changed plugs/leads/dist cap done the fuel mixture checked the TPS, changed the blue temp sensor. any ideas guys?

[Ant]

Check carnk sensor wiring is OK, it chafes on the front pulleys and can short causing symptoms as you've described, no need to remove it, just shine a toch in the area behind the w/pump and check its not touching the back face

if you have a multimeter then C/shaft sensor is 550 ohms in good condition( check @ plug)

HTH

[stuartevans]

I tested the crank sensor 550 ohms ok and cable seems to be good as well. With the meter conected and turning the crank should there be much of a difference in readings?

[Ant]

turning by hand will show no respone, TBH you'd need a 'scope to test the VR output, if the car runs/starts then its working M8

Next port of call, open the AFM top cover and have a peek inside , check for any wear on the carbon track inside, either way a good clean is time well invested

Post 88 E30's run lean as hell in the midrange, that can cause the slight judder/surge you're experiencing(sp)

[stuartevans]

Ant mine is a 89 E30 so guess i may have the midrange issue you suggest. I have a Zonechip which i have not fitted yet would this help the midrange?