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« on: September 01, 2012, 05:07:53 AM »
After reading through a bunch of threads trying to match symptoms, it seems like idle issues and valvetrain noises are an inherent part of the M42 ownership experience.
But I've got one I don't think anyone has noted before.
To wit--starting a car, whether cold or warm, usually involves twisting the key, a couple cranks or more, and then the engine fires.
What has happened every so often with my E36 M42 is that, when warm, the engine fires almost immediately after the key twist, and doesn't "need" the cranks.
In the past, this has resulted in situations where the engine just goes directly to the normal 600-850rpm idle speed, no issues.
However, in the more recent past, things have seemingly gone downhill after these quicker "instant" starts.
A couple months ago, the engine started, but evidently due to some unknown issue, resulted in the electrical system running undervoltage, with the radio cutting in and out, and the ABS light coming on, before the Check Engine light eventually came on (and stored an insufficient voltage fault).
However, on the way home, the engine ran and felt completely normal, and all the lights eventually went out before I got home. Took another test drive after getting home, and all seemed normal.
The following day, I tried to start the car again, and it cranked slowly, like the battery had been drained. Put it on a charger, and it cranked and started fine afterward.
Thinking the alternator was failing, I tested it at home with a DMM, as well as having it tested by the "load" tester at a parts store. It passed all tests, with voltage in the 13v range at idle, and 14+ at higher rpm.
The battery had had one deep, deep discharge incident while I was away a couple years ago, so I thought that might have finally caught up with it, but it acted, and has acted fine since then.
No issues in the interim, so I chalked it up to an weird, but isolated incident.
Now, we come to this week, and two days in a row, in the middle of the sequence of stop/starts while running errands, the engine "quick" started, but wouldn't stay running, and stall. It acted just like when the fuel pump expired a little less than two years ago--start, stumble, and then stall. Trying to start it again, and manipulating the throttle has gotten it started, and idling, a bit poorly at first, but fine after a few moments.
Subsequent starts on the errands, no problem. Whatever is happening, it isn't doing so consistently, or at least in a discernible pattern yet. No faults stored in the DME.
I know E36s, at least, can be subject to what's known as the "car wash syndrome," where starting the car, then running it briefly before shutting it down again can result in a hard/no start condition, like a flooded engine from the old days. But, these are different conditions, with a warm engine and longer running.
Sorry this has been so long, but any thoughts from the peanut gallery?
I've done the basic checks of the connectors, poked and prodded the relays, and disconnected the battery to clear the DME and reset the adaptive memory.
Next is to clean the (original) ICV, and whatever else might be suggested. I don't think (hope) the fuel pump has gotten cranky so quickly, but I do make full use of the tank capacity most of the time.
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