I have been battling an intermittent miss with my 1987 325. When the moderate miss occurs at light acceleration and cruising speed, it can also be felt at idle. You can shut it off and drive it 10 minutes latter and it might not miss at all. My suspicion it that it is the speed sensor mounted on the bellhousing (automatic, Motronic). I'm really at a loss and am looking for assistance.
Here is what has already been recently repaired on this car. It has about 195,000 miles but as noted below, much has been replaced.
New plugs, wires, rotor and cap
Coil has been checked and swapped with my '90 325I
Re-built head 2,500 miles ago, new timing belt, valves just re-adjusted
New fuel pressure regulator
New throttle position switch and oxygen sensor
New variable temperature sensor
Just changed to another used air flow meter but no change with the miss.
The fuel injectors were removed and sent off to be cleaned and flow tested.
As a note, I also had the miss prior to changing the head but at that time, I thought that it might be caused by the leaking valves that were worn on several cylinders. The car was due for a fresh head, but more importantly, the head gasket was leaking a ton of oil and it didn't pay to change the gasket and put the same head back on.
Any thoughts? It could be the computer but I don't know how to check it out. When it doesn't have the miss, it seems to run fine even when wide open so I don't think that it is mechanical.
Here is what has already been recently repaired on this car. It has about 195,000 miles but as noted below, much has been replaced.
New plugs, wires, rotor and cap
Coil has been checked and swapped with my '90 325I
Re-built head 2,500 miles ago, new timing belt, valves just re-adjusted
New fuel pressure regulator
New throttle position switch and oxygen sensor
New variable temperature sensor
Just changed to another used air flow meter but no change with the miss.
The fuel injectors were removed and sent off to be cleaned and flow tested.
As a note, I also had the miss prior to changing the head but at that time, I thought that it might be caused by the leaking valves that were worn on several cylinders. The car was due for a fresh head, but more importantly, the head gasket was leaking a ton of oil and it didn't pay to change the gasket and put the same head back on.
Any thoughts? It could be the computer but I don't know how to check it out. When it doesn't have the miss, it seems to run fine even when wide open so I don't think that it is mechanical.