99 Passat 1.8t, AEB, tip
I have been having this problem for awhile now. Some days it starts right up, others it just cranks and cranks but doesnt fire, and then others it starts but then runs really rough like its misfiring, until it eventually clears and then runs normal. It seems to be worse the longer the car sits, but once it starts for the first time of the day its almost always fine the rest of the day. Although i will still get slightly rough starts where it misses a few times but then smooths right out.
I have vag-com, and the only dtc's im getting are for random intermittent misfires in cylinders 2 and 3. I have had issues with misfires before, and its ALWAYS been in 2 and 3. It definitely feels like im not getting fuel or not getting a spark. I have a feeling that its an electrical issue, either a faulty sensor or bad ground or relay or something....?
I have checked (only visually) the grounds that i know where they are, all seem to be intact...
I have done quite a few things to this car, and all of these have been done since i have had this problem...
-new o2 sensor
-new fuel injectors
-cleaned the MAF
-new intake air sensor
-new coolant temp sensor
-swapped in a different ECU
im sure there are other things too, but those are the most recent and the ones i can remember off the top of my head
I was ALMOST convinced it was cold weather related, but then yesterday and today i had the same issues. Its not hot here in cny by any means, but it has definitely been warmer. Since the nicer weather broke a couple of weeks ago it has been great, up until yesterday and today.
Anyway, does anybody have any input or guidance??? I have already thrown alot of parts at this thing, but i considered most of them to be good maintenance items. I dont really want to keep throwing random things at it though. So i would love to hear from people the have had similar issues, or any good educated guesses!!!