Gents (are there any women in the E24 forum?),
For a few months now I've been living with a very intermittent problem: I'll be driving along, fat dumb and happy, and my power will momentarily cut out entirely. This isn't a hesitation, like a misfire, it's complete loss as if I'm lifting off the accelerator. No accompanying dash lights, either. If it happens at a stop, the car dies, but it usually happens at speed and then comes back within 1-2 seconds. Very occasionally (1x/month) power doesn't come back, I pull over to the side with hazards flashing, wait a minute, and the car starts back up and I make it home.
Here's what I've replaced in the past year (that could be suspect)-
Main FI relay
Fuel pump relay
Ignition wires, dizzy cap, rotor
Spark plugs
O2 sensor
Injectors (flow-balanced, new filters/seals, all resistance checked OK)
Bell housing speed and reference sensors
Vacuum hoses
TPS (it's the uncommon multi-switch one, and operates as advertised)
Two questions:
Can the transmission (4HP22) control unit cause this? Problem seems slightly more pronounced under heavy load, but it's almost as likely to happen on a flat road regardless of speed.
Should I suspect the neutral safety switch at all? I know it prevents starting if not in neutral/park, but if it has a bad connection will it also cut the engine?
I'm starting to suspect a wiring issue, most likely between the main relay and ECU. I'm about to go outside and check for any resistance between all the injection components and the ECU, per the hiperformancestore procedure. I'll report back if I find anything, but in the meantime wanted to put out the poll here and see if there's anything I'm considering.
As always thanks for your collective wisdom, or at least your humor!
Pete
Intermittent power loss - All hare-brained theories welcomed
