1998 A4 2.8 Cylinder Misfire Rough Idle after sitting for weeks
#11
I looked into the NGK parts catalogue and for the 2.8 engines the recommended spark plugs are:
AFC - BKUR6ET-10
AQD - BKR6EKUB
ACK - BKR6EKUB
APR - BKR6EKUB
ALG - BKR6EKUB
AMX - BKR6EKUB
I wrote down all the engine made around 1998 because you didn't specify your engines code. Anyway no engine uses NGK BKR6EGP plugs.
Your spark plugs are NGK Iridium and on http://www.ngk.com/results_fitment.asp?pid=bkr6egp I saw that they are ok for the following engines: AFC, AHA.
So compare your engine code with the ones that I listed above and see if you can find a match.
AFC - BKUR6ET-10
AQD - BKR6EKUB
ACK - BKR6EKUB
APR - BKR6EKUB
ALG - BKR6EKUB
AMX - BKR6EKUB
I wrote down all the engine made around 1998 because you didn't specify your engines code. Anyway no engine uses NGK BKR6EGP plugs.
Your spark plugs are NGK Iridium and on http://www.ngk.com/results_fitment.asp?pid=bkr6egp I saw that they are ok for the following engines: AFC, AHA.
So compare your engine code with the ones that I listed above and see if you can find a match.
#13
I looked into the NGK parts catalogue and for the 2.8 engines the recommended spark plugs are:
AFC - BKUR6ET-10
AQD - BKR6EKUB
ACK - BKR6EKUB
APR - BKR6EKUB
ALG - BKR6EKUB
AMX - BKR6EKUB
I wrote down all the engine made around 1998 because you didn't specify your engines code. Anyway no engine uses NGK BKR6EGP plugs.
Your spark plugs are NGK Iridium and on http://www.ngk.com/results_fitment.asp?pid=bkr6egp I saw that they are ok for the following engines: AFC, AHA.
So compare your engine code with the ones that I listed above and see if you can find a match.
AFC - BKUR6ET-10
AQD - BKR6EKUB
ACK - BKR6EKUB
APR - BKR6EKUB
ALG - BKR6EKUB
AMX - BKR6EKUB
I wrote down all the engine made around 1998 because you didn't specify your engines code. Anyway no engine uses NGK BKR6EGP plugs.
Your spark plugs are NGK Iridium and on http://www.ngk.com/results_fitment.asp?pid=bkr6egp I saw that they are ok for the following engines: AFC, AHA.
So compare your engine code with the ones that I listed above and see if you can find a match.
I looked on that website and for those engines, the ones I bought are under the title "super class" and the iridiums are under the title "premium class" so Im assuming the plugs are good for the car, right?
Just to review what I have done to the car to this point.
1) I couldn't start the car
2) Car sat for weeks while trying to diagnose and get car started
3) Car was towed three times during these weeks of sitting
4) Replaced the ignition switch and starter and car started right up but ran rough
5) Scanned with Vag-com and gave me random misfires in 1, 2, 3, and 6 cylinders - intermittent
6) Realigned throttle body but still ran rough
7) Cleaned throttle body but still ran rough
8) Replaced almost all visible vacuum lines and car still ran rough (any hidden ones I should know about?)
9) Replaced all spark plugs and filled engine with 89 gas and car is still idling rough and CEL is showing the same cylinder misfire codes as before.
I am really running out of ideas and could use any suggestions!
Last edited by mmdambro; 04-09-2011 at 11:43 AM.
#15
I read that they changed the spark plug specs for these cars to deal with the rough idle. Is that true? Should I get the iridium or just stick with the platinums?
From all the sources I found, it said that my engine was AHA though I have not found it on my car yet.
Last edited by mmdambro; 04-09-2011 at 12:33 PM.
#16
UPDATE:
I took the new spark plugs out and put in the BKR6EKUB, these are apparently the stock plugs for the car. I still have a rough idle but now the only codes I am getting are for cylinder misfires at cylinders 3 and 6. I was initially thinking this was the coil packs, but 3 and 6 are at different coils. Anyone have any input?
I took the new spark plugs out and put in the BKR6EKUB, these are apparently the stock plugs for the car. I still have a rough idle but now the only codes I am getting are for cylinder misfires at cylinders 3 and 6. I was initially thinking this was the coil packs, but 3 and 6 are at different coils. Anyone have any input?
#17
I am trying to get the check engine light to come back on to see if switching the plugs causes a misfire in different cylinders.
While driving these codes were showing up on the vag:
2 Faults Found:
17536 - Fuel Trim; Bank 1 (Mult): System too Lean
P1128 - 35-00 - -
17538 - Fuel Trim; Bank 2 (Mult): System too Lean
P1130 - 35-00 - -
Readiness: 0010 1101
While driving these codes were showing up on the vag:
2 Faults Found:
17536 - Fuel Trim; Bank 1 (Mult): System too Lean
P1128 - 35-00 - -
17538 - Fuel Trim; Bank 2 (Mult): System too Lean
P1130 - 35-00 - -
Readiness: 0010 1101
#18
"System too lean" error code means that you have too much oxygen in the exhaust system so maybe you still have ignition problems considering that there are misfires on some cylinders. Try to check the coils by looking at them when it's really dark outside and if you see sparks when someone else turns the ignition key then it's time for a replacement.
#20
Ok so I think I solved this problem for the rough idle. I went back in and replaced every vacuum line and while I was in there I found a line that I may have forgotten to hook back up while I was doing the starter replacement. Once I hooked everything back up and started it up, it was running perfectly. Looks like my solution was just a missed vacuum line. Though the others really needed to be replaced.