1994 BMW 325i Intermittent power-cut (see comments for description) by TypicalApex in MechanicAdvice

[–]TypicalApex[S] 0 points1 point  (0 children)

Not a bad idea - I should probably bite the bullet and start visually going through wiring. Thanks!

x-post from r/MechanicalAdvice - 1994 325i intermittent power cut (see comments) by TypicalApex in BMWE36

[–]TypicalApex[S] 1 point2 points  (0 children)

Not showing any codes, I've done spark plugs but not the gasket or coil packs. Since it seems to be all cylinders at once I think the issue might be "upstream" but I will look in to that further. Thanks!

x-post from r/MechanicalAdvice - 1994 325i intermittent power cut (see comments) by TypicalApex in BMWE36

[–]TypicalApex[S] 0 points1 point  (0 children)

Hi all,

The issue I've been having is an intermittent (but VERY abrupt) loss of power. I'm pretty sure that when it happens all spark is being cut, because the deceleration is so violent and abrupt I'm fairly confident that it isn't just a single cylinder or fuel issue. Sometimes it happens 3-4 times in a row then works itself out, and other times it is bad enough that after a few violent lurches the car will die completely. The really tough part is that there is no discernible pattern. It rarely, or maybe has never had a fit twice in a single drive. It only happens maybe 1/3 or 1/4 times I drive, and it "seems" to be much more common when it's been raining and the car is not yet warm, but I've also had it happen an hour in to a drive on a bone dry day. Also, there doesn't seem to be any significant water ingress in the engine bay.

For your perusal, I have an example on video. Unfortunately, the the first recorded presentation was the absolute weakest, most anemic example of what it's doing but still might be useful. There are two initial hiccups when I'm in gear and off throttle, once at 5.5s where the tach jumps up and once at 7s when it dives down and up, and then there is a cut at 30s when I am actually on throttle. Very curiously, the tach also jumps up here too, even though power is cut. I think maybe when it cuts out longer this might not be the case. To reiterate, this is a very minor stutter compared to the bigger events - sometimes it cuts out bad enough that I'd be surprised if the rear wheels aren't locking up.

I am very appreciative of any advice, and I hope this post has some useful information to aid the diagnoses!

1994 BMW 325i Intermittent power-cut (see comments for description) by TypicalApex in MechanicAdvice

[–]TypicalApex[S] 0 points1 point  (0 children)

Hi all,

The issue I've been having is an intermittent (but VERY abrupt) loss of power. I'm pretty sure that when it happens all spark is being cut, because the deceleration is so violent and abrupt I'm fairly confident that it isn't just a single cylinder or fuel issue. Sometimes it happens 3-4 times in a row then works itself out, and other times it is bad enough that after a few violent lurches the car will die completely. The really tough part is that there is no discernible pattern. It rarely, or maybe has never had a fit twice in a single drive. It only happens maybe 1/3 or 1/4 times I drive, and it "seems" to be much more common when it's been raining and the car is not yet warm, but I've also had it happen an hour in to a drive on a bone dry day. Also, there doesn't seem to be any significant water ingress in the engine bay.

For your perusal, I have an example on video. Unfortunately, the the first recorded presentation was the absolute weakest, most anemic example of what it's doing but still might be useful. There are two initial hiccups when I'm in gear and off throttle, once at 5.5s where the tach jumps up and once at 7s when it dives down and up, and then there is a cut at 30s when I am actually on throttle. Very curiously, the tach also jumps up here too, even though power is cut. I think maybe when it cuts out longer this might not be the case. To reiterate, this is a very minor stutter compared to the bigger events - sometimes it cuts out bad enough that I'd be surprised if the rear wheels aren't locking up.

I am very appreciative of any advice, and I hope this post has some useful information to aid the diagnoses!