mmdambro

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 idled 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 with NGK BKR6EKUB and filled tank with 89 gas and car is still idling rough but some of the codes have cleared. I am now only getting codes for a misfire on cylinders 3 and 6.

Any suggestions?

4Driver4

Pull codes, post codes?
Or is "misfire" the only code you see?

mmdambro

These are the codes that are showing up


3 Faults Found:

16684 - Random/Multiple Cylinder Misfire Detected
P0300 - 35-00 - -
16687 - Cylinder 3: Misfire Detected
P0303 - 35-00 - -
16690 - Cylinder 6: Misfire Detected
P0306 - 35-00 - -

4Driver4

I'd probably do a leak-down test.

IIRC, 3 and 6 share a coil. Are you sure that the plugs are good (have you swapped them with other cylinders?) and the coils are working?

mmdambro

When I look at the coils, 3 and 6 are different coils. And two cylinders go into each coil, correct?

So, to answer your questions:
- no I don't know if the coils are working...can I test them?
- while I wait for your response I am going out to switch the plugs around and see if anything changes.

4Driver4

Do a leak down or compression test. Compression is step one.

mmdambro

ok I am going to have to google those. I am not sure what they are. How do I do a compression test on the a4?

mmdambro

I am trying to get the check engine light to come back on to see if switching the plugs changed anything.

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

mmdambro

OK I switched the plugs from cylinders 3 and 6 to cylinders 2 and 5. Now I am getting these codes

6 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 - -
16684 - Random/Multiple Cylinder Misfire Detected
P0300 - 35-00 - -
16685 - Cylinder 1: Misfire Detected
P0301 - 35-00 - -
16687 - Cylinder 3: Misfire Detected
P0303 - 35-00 - -
16686 - Cylinder 2: Misfire Detected
P0302 - 35-00 - -

Readiness: 0010 1101

turbo510

That could be caused by the MAF (mass air flow) sensor. You can start by taking the MAF sensor housing out, then using an appropriate cleaner like CRC MAF sensor cleaner, or putting the whole thing in a large baggie with isopropyl alcohol and swishing it well. While at it, spray electronic connector cleaner or WD-40 into the MAF connector; I'd do all of the accessible connectors, including injectors, ignition module, O2s, etc. Also be on the lookout for air leaks downstream of the MAF, such as the duct hose.

Afterwards, use VAG-COM to see what the g/S air flow readings are, especially while idling. I don't remember exactly, but something aroud 5g/S at idle is about right.