Hi all,
'87 325i m20b25 5 speed build date 6/87
Over the past couple months I've noticed my bmw doesn't have as much power as it used to. It has been a steady decline. It's mostly apparent when starting from first gear (you have to press the pedal more than normal) but is also noticeable in the 2k-4k rpm range (when passing or accelerating on an onramp, for example).
My car has a 173 ecu 17lb MarkD 91 octane chip (about 5k mi old), but I use 93 because that is what's available here in Connecticut. Spark plugs (bosch coppers) and wires are 10k old, cap/rotor are 30k, fuel filter is 40k, rebuilt 17lb m50 injectors 20k, recently changed the oil, air filter is clean enough, I recently adjusted the AFM to correct track wear (after these symptoms began), new engine bay fuel lines 20k ago, new intake manifold gaskets, oil return tube tube o rings 20k. I did the tb 30k ago. I adjusted my throttle cable to correct for slack a few years ago and it is still taut.
I've disconnected the battery just now and am waiting the 45 mins to reconnect and retest. My brake booster failed in the form of a huge vacuum leak over the winter and I had to wait until spring before replacing it. I'm hoping the ecu learned how to run the car with a vacuum leak and is now having trouble relearning under normal conditions. Because that would coincide with these symptoms. I haven't tried putting the stock chip back in yet.
Tomorrow morning I'll try adjusting the valves because it sounds like they're out of spec. It's due for it. But when I got the car it was in a much more extreme state of neglect and still ran better than it does now.
The car is hot now otherwise I would check spark plug condition.. but they are only 10k old. I've searched of course and that's led me back to the battery trick. I've already replaced everything normally suggested to replace. Anything I'm not thinking of?
'87 325i m20b25 5 speed build date 6/87
Over the past couple months I've noticed my bmw doesn't have as much power as it used to. It has been a steady decline. It's mostly apparent when starting from first gear (you have to press the pedal more than normal) but is also noticeable in the 2k-4k rpm range (when passing or accelerating on an onramp, for example).
My car has a 173 ecu 17lb MarkD 91 octane chip (about 5k mi old), but I use 93 because that is what's available here in Connecticut. Spark plugs (bosch coppers) and wires are 10k old, cap/rotor are 30k, fuel filter is 40k, rebuilt 17lb m50 injectors 20k, recently changed the oil, air filter is clean enough, I recently adjusted the AFM to correct track wear (after these symptoms began), new engine bay fuel lines 20k ago, new intake manifold gaskets, oil return tube tube o rings 20k. I did the tb 30k ago. I adjusted my throttle cable to correct for slack a few years ago and it is still taut.
I've disconnected the battery just now and am waiting the 45 mins to reconnect and retest. My brake booster failed in the form of a huge vacuum leak over the winter and I had to wait until spring before replacing it. I'm hoping the ecu learned how to run the car with a vacuum leak and is now having trouble relearning under normal conditions. Because that would coincide with these symptoms. I haven't tried putting the stock chip back in yet.
Tomorrow morning I'll try adjusting the valves because it sounds like they're out of spec. It's due for it. But when I got the car it was in a much more extreme state of neglect and still ran better than it does now.
The car is hot now otherwise I would check spark plug condition.. but they are only 10k old. I've searched of course and that's led me back to the battery trick. I've already replaced everything normally suggested to replace. Anything I'm not thinking of?
Comment