Rough running / stalling after new alternator 2
07-24-2010, 09:05 AM
#1
Audiworld Junior Member
Thread Starter
Join Date: Jan 2008
Posts: 26
Likes: 0
Received 0 Likes
on
0 Posts
Rough running / stalling after new alternator 2
With no feedback on this issue I am trying to figure out what to do, I live in Carmel Valley Ca. on the Monterey peninsula. We don’t really have an Audi dealer in out area, for a few years the service dep. was at a GMC truck dealer but they are out of business, I think it may now be at a Kia dealer. I am not sure I would trust them to service my car.
So I am considering buying the Vag Com But I am wondering if I don’t see a CEL will the Vag Com help diagnoses the issue. I will go over the Issue again, to begin with the battery light a few days later the battery completely drained and the car stalled, after testing we determined the alternator was the issue, we replaced the alternator and checked for corrosion on the connection near the right front wheel. The car will start and run (idle and rev) properly for 30 to 60 seconds and then begin to hesitate, pushing the throttle will make the engine bog as if it is starved for fuel and eventually stall. This can be repeated numerous times with the same result. On another note I would like to say that I have seen a lot of threads regarding the A8 and reliability,I purchased this car for my wife as a family car ten years ago and it has been a daily driver as well as being used for long road trips across the country. Our A8 now has over 150,000 miles on it and has been one of the best cars I have ever owned.Other that maintenance all i have had to do on the car is replace some front suspension parts valve cover gaskets and front wheel speed sensors. the biggest issue with this car is that when on the hi way on a road trip every other car seems to be in my way. i would and most likely and probably will buy another A8 when and if our 97 early build car is worn out.
So I am considering buying the Vag Com But I am wondering if I don’t see a CEL will the Vag Com help diagnoses the issue. I will go over the Issue again, to begin with the battery light a few days later the battery completely drained and the car stalled, after testing we determined the alternator was the issue, we replaced the alternator and checked for corrosion on the connection near the right front wheel. The car will start and run (idle and rev) properly for 30 to 60 seconds and then begin to hesitate, pushing the throttle will make the engine bog as if it is starved for fuel and eventually stall. This can be repeated numerous times with the same result. On another note I would like to say that I have seen a lot of threads regarding the A8 and reliability,I purchased this car for my wife as a family car ten years ago and it has been a daily driver as well as being used for long road trips across the country. Our A8 now has over 150,000 miles on it and has been one of the best cars I have ever owned.Other that maintenance all i have had to do on the car is replace some front suspension parts valve cover gaskets and front wheel speed sensors. the biggest issue with this car is that when on the hi way on a road trip every other car seems to be in my way. i would and most likely and probably will buy another A8 when and if our 97 early build car is worn out.
07-24-2010, 03:21 PM
#3
AudiWorld Super User
It's the right mileage for this to be a likely problem, esp if it seems starved for gas.
I assume you're sure the battery charge problem is solved (with or without battery light)...it probably is and was just coincidental with your present problem...esp if the car seems to have a strong starter on restarts.
I'm not very well versed on fuel pump problems on these cars in particular...just know it's supposed to be a sore spot on A8's at higher mileage.
Your description does, however, sound generically like a fuel pump symptom. Had one go bad on a Passat and limped it home, about 60 seconds at a time (constant restarts)...it seemed to "gravity feed"(?) just enough fuel to run for a few seconds at a time. But the VW had dual pumps...one in the tank (transfer pump)that feeds to a reservoir where a pressure pump feeds the fuel injection. My inside the tank transfer pump was bad.
I have an A8, but haven't read heavily into the fuel pump system (in Bentley, etc..)...just countless war stories on all the A8 forums. As I understand, it's just one pump inside the tank(?).
Hopefully the guys here with personal experience with your system and the proper expertise will chime in.
I assume you're sure the battery charge problem is solved (with or without battery light)...it probably is and was just coincidental with your present problem...esp if the car seems to have a strong starter on restarts.
I'm not very well versed on fuel pump problems on these cars in particular...just know it's supposed to be a sore spot on A8's at higher mileage.
Your description does, however, sound generically like a fuel pump symptom. Had one go bad on a Passat and limped it home, about 60 seconds at a time (constant restarts)...it seemed to "gravity feed"(?) just enough fuel to run for a few seconds at a time. But the VW had dual pumps...one in the tank (transfer pump)that feeds to a reservoir where a pressure pump feeds the fuel injection. My inside the tank transfer pump was bad.
I have an A8, but haven't read heavily into the fuel pump system (in Bentley, etc..)...just countless war stories on all the A8 forums. As I understand, it's just one pump inside the tank(?).
Hopefully the guys here with personal experience with your system and the proper expertise will chime in.
Last edited by silverd2; 07-24-2010 at 03:31 PM.
07-24-2010, 03:59 PM
#4
AudiWorld Super User
P.S. Please do NOT automatically assume fuel pump, based on my post.
That may be the worst case. There's the fuel filter and other electronic parts that could cause fuel starvation...IF that's the problem...and not a spark loss problem (?).
Like I said, other guys here know much more about the particulars than me....Hope we hear from em.
That may be the worst case. There's the fuel filter and other electronic parts that could cause fuel starvation...IF that's the problem...and not a spark loss problem (?).
Like I said, other guys here know much more about the particulars than me....Hope we hear from em.
07-26-2010, 11:39 AM
#5
Audiworld Junior Member
Thread Starter
Join Date: Jan 2008
Posts: 26
Likes: 0
Received 0 Likes
on
0 Posts
Rough Running / Stalling after new alternator
P.S. Please do NOT automatically assume fuel pump, based on my post.
That may be the worst case. There's the fuel filter and other electronic parts that could cause fuel starvation...IF that's the problem...and not a spark loss problem (?).
Like I said, other guys here know much more about the particulars than me....Hope we hear from em.
That may be the worst case. There's the fuel filter and other electronic parts that could cause fuel starvation...IF that's the problem...and not a spark loss problem (?).
Like I said, other guys here know much more about the particulars than me....Hope we hear from em.
I guess I should spring for the Vac Com, I don't know if the Vag Com will re flash the ECU But my concern is that with total power loss wile the engine is running the ECU could have been damaged or may need a re flash if this is possible on my car.
07-26-2010, 12:22 PM
#6
AudiWorld Super User
Some symptoms are a little diff, but some sound the same..."no codes"..."stalls even with throttle on"...You probably already have, but look at the thread near this one:
"Completely Random Stalling"
They're talkin about possibly vacuum loss, hose broken or off(?)
Worth a look, but granted...either problem might not be vacuum...something fuel delivery related, which can also be caused by vacuum loss at the wrong (right) point(?)
"Completely Random Stalling"
They're talkin about possibly vacuum loss, hose broken or off(?)
Worth a look, but granted...either problem might not be vacuum...something fuel delivery related, which can also be caused by vacuum loss at the wrong (right) point(?)
07-26-2010, 04:12 PM
#7
Audiworld Junior Member
Thread Starter
Join Date: Jan 2008
Posts: 26
Likes: 0
Received 0 Likes
on
0 Posts
Rough running / stalling after new alternator 3
Some symptoms are a little diff, but some sound the same..."no codes"..."stalls even with throttle on"...You probably already have, but look at the thread near this one:
"Completely Random Stalling"
They're talkin about possibly vacuum loss, hose broken or off(?)
Worth a look, but granted...either problem might not be vacuum...something fuel delivery related, which can also be caused by vacuum loss at the wrong (right) point(?)
"Completely Random Stalling"
They're talkin about possibly vacuum loss, hose broken or off(?)
Worth a look, but granted...either problem might not be vacuum...something fuel delivery related, which can also be caused by vacuum loss at the wrong (right) point(?)
Trending Topics
07-26-2010, 05:24 PM
#8
AudiWorld Super User
Don't know if Vag.com will tell you more...if a reader doesn't show any codes.
All I use is a hand-held code reader...would love to have full Vag.com eventually, though.
Vag.com may tell you more about an ECM problem (?). The ECM DOES make all the final decisions about fuel and spark, if it's not an individual component problem.
I know there are other folks here with a lot more knowledge about Vag & Ecm's than me. But, not bein able to get to your car, it may come down to someone with the stuff and the specific knowledge hookin up Vag, fuel pressure gauge, etc...to track it down.
All I use is a hand-held code reader...would love to have full Vag.com eventually, though.
Vag.com may tell you more about an ECM problem (?). The ECM DOES make all the final decisions about fuel and spark, if it's not an individual component problem.
I know there are other folks here with a lot more knowledge about Vag & Ecm's than me. But, not bein able to get to your car, it may come down to someone with the stuff and the specific knowledge hookin up Vag, fuel pressure gauge, etc...to track it down.
Last edited by silverd2; 07-26-2010 at 06:54 PM.
08-26-2010, 08:57 PM
#9
AudiWorld Newcomer
Join Date: Aug 2010
Posts: 2
Likes: 0
Received 0 Likes
on
0 Posts
I just purchased a 1999 A8 183k miles that ran fine for a day and is now doing the same thing with no engine light coming on. It will start up just fine and run for a few seconds and sometimes 10-15 seconds and then idle rough and stall. Weird because like I said this car ran great yesterday. The problem started this afternoon out of nowhere and I had to have it towed back to my place. Now it's sitting in the garage with a charger on the battery overnight just to make sure that is ok. I will post a video of what it is doing tomorrow but does anyone have any other advice on this issue? Without a check engine light I don't have a clue.
08-26-2010, 08:58 PM
#10
AudiWorld Newcomer
Join Date: Aug 2010
Posts: 2
Likes: 0
Received 0 Likes
on
0 Posts
I just purchased a 1999 A8 183k miles that ran fine for a day and is now doing the same thing with no engine light coming on. It will start up just fine and run for a few seconds and sometimes 10-15 seconds and then idle rough and stall. Weird because like I said this car ran great yesterday. The problem started this afternoon out of nowhere and I had to have it towed back to my place. Now it's sitting in the garage with a charger on the battery overnight just to make sure that is ok. I will post a video of what it is doing tomorrow but does anyone have any other advice on this issue? Without a check engine light I don't have a clue.