E30 Zone

My 1990 320i cab has the most annoying fault I've ever known,can someone help.When driving the car around 1k-1.5k it misfires,anything after those revs it goes alot better but still seems to be misfiring.Also at standstill when you blip the throttle the engine picks up,but when you blip it again, it fails to pick up on all 6 cylinders.A week or so ago it didn't start for a minute or so,the one and only this has happened.The things that have been changed and checked so fare are- fuel filter,Main rubber hose on inlet manifold,no fault codes have showed up when tested,all 6 plug leads taken off one at a time,engine note changes each time,HT cap has been checked and seems to be fine the same goes for the rotor arm.Valve clearances been done so they are fine.Airflow meter changed,fuel pump regulator changed.PLEASE CAN SOMEONE HELP as I've had 3 people look at it with no success yet.

Not wanting to state the obvious but have you checked the plugs? It's the one thing you have not listed too.

you need to clean out the Throttle position sensor, (TPS) and the idle control Valve,

have the throttle body correctly set-up if it's been adjusted by one of the 3 guys who have worked on it !

e30topless wrote:you need to clean out the Throttle position sensor, (TPS) and the idle control Valve,

have the throttle body correctly set-up if it's been adjusted by one of the 3 guys who have worked on it !

I've had similar faults, & cleaning out the Throttle housing with Carb.Cleaner, works wonders, it solves a number of alot of running issues!

I had a very similar problem with a 325, and replaced everything as you have. Turned out to be the flywheel sensor I think, it was a long time ago!

Just in case all else fails, mine was like that and it turned out to be the HT leads.

have you tried a different coil pack?

This is one of those annoying problems that could be loads of things.

On my 320. It was the AFM. The not starting with simlar lack of power was the Temp Sensor.