Rough driving when at constant speed (after dead alternator)
02-12-2007, 01:29 PM
#1
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Rough driving when at constant speed (after dead alternator) Question: when I drive my (manual) T/A at a constant speed, it drives very *rough*, i.e., there is always a slight acceleration/decelation that is very noticeable. This is especially noticeable in 2d gear and at slow/city speeds, but can be felt at any speed and any gear.
I believe this started recently after I had driven the car down to its LAST volt-amp, when my alternator had died and I saw the voltmeter go down to <10V steady, more and more of the warning lights came on in the dashboard, until it all clunked out and nothing worked any more. (I guess the engine stopped running b/c the fuel injection is electronically regulated and needs battery / alternator juice?) I had a new alternator installed, so that is no longer an issue.
Everything else works, and the idle is also not a rough idle in and of itself.
Do you think the driving-to-death with bad alternator has caused this rough ride? How do I fix it / what is the cause? Does a chip etc. have to be reprogrammed?
I believe this started recently after I had driven the car down to its LAST volt-amp, when my alternator had died and I saw the voltmeter go down to <10V steady, more and more of the warning lights came on in the dashboard, until it all clunked out and nothing worked any more. (I guess the engine stopped running b/c the fuel injection is electronically regulated and needs battery / alternator juice?) I had a new alternator installed, so that is no longer an issue.
Everything else works, and the idle is also not a rough idle in and of itself.
Do you think the driving-to-death with bad alternator has caused this rough ride? How do I fix it / what is the cause? Does a chip etc. have to be reprogrammed?
02-13-2007, 08:36 PM
#2
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I would check the coils. You are probably not getting full output from one or more. Had a mystery problem like that, that didn't light the check engine light but had similar symptoms. You have plugged a code reader in to check for stored codes, I assume? A chip should have no effect, it's a basic spark problem.
02-19-2007, 07:57 PM
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thanks people -- hadn't thought of the coils, thanks. And -- no -- I have not had time to check the codes yet, since some idiot tried to break into my car in the meantime, jacking up the passenger-side door lock. (I guess I'll get a 'shaved door-lock' lock out of this one, as I plan to "eliminate" the lock and simply use the wireless power-lock FOB to open/close. never used the key/lock anyhow.)
So, BACK on topic: you think it's the coils? I have never changed my plugs on my '00 WS6, nor the coils (I take it there are 2 coils, one for each L/R-hand bank?)... how much am I spending here, and is the install easy to do at home? thanks!
So, BACK on topic: you think it's the coils? I have never changed my plugs on my '00 WS6, nor the coils (I take it there are 2 coils, one for each L/R-hand bank?)... how much am I spending here, and is the install easy to do at home? thanks!
02-20-2007, 02:09 PM
#6
In reply to this and your PM, I don't know, and I'm the wrong person to ask. There are a lot better people to ask than me.
There is one coil pack per cylinder. Buying 8 MSD coils would cost a fortune (to me, but not for most on here) with arguable power gains. Some say negligable gains; some say, like 10 rwhp or whatever... But, they look cool as hell and no doubt do their job extreamly well. I'm of the "probably negligable gains" camp, but i love how they look. That's why I made the wise crack.
What I would do? Autozone for free scan and if the car throws no codes, I would go ahead and change the plugs and wires if needed and ask a shop how to check the coils if you really, really want to do it yourself. Otherwise, ask a shop to check them. I'd have a shop change the plugs and wires at the same time.
There is one coil pack per cylinder. Buying 8 MSD coils would cost a fortune (to me, but not for most on here) with arguable power gains. Some say negligable gains; some say, like 10 rwhp or whatever... But, they look cool as hell and no doubt do their job extreamly well. I'm of the "probably negligable gains" camp, but i love how they look. That's why I made the wise crack.
What I would do? Autozone for free scan and if the car throws no codes, I would go ahead and change the plugs and wires if needed and ask a shop how to check the coils if you really, really want to do it yourself. Otherwise, ask a shop to check them. I'd have a shop change the plugs and wires at the same time.
02-20-2007, 02:29 PM
#7
TECH Senior Member
Get the code(s) read. Might be something like P1336 CKP system variation not learned - throws when the ignition switch is in the ON position until the battery is drained. Just an example...
