E3 Running Issues; Backfire

[davidmontgomery]

Hey guys,

I have a 72' Bavaria with Auto Trans. Ive owned it for a few months, and I'm still trying to get used to her and see what's "normal". But, today is not normal. Since my oil change (see below) The engine has been idling real rough till the engine heats up (I think i know why; see below) I drive about 15miles to work one way, with a nice stretch where I can keep her around 60mph. Today, almost home, my engine started bouncing while going about 45mph, then got real rough and backfired. Once it backfired, i saw a big plume of smoke behind me, then my car ran smoothly.

So far, what I've done is:
-change the alternator (pulley broke on the first one)
-change spark plugs (second cylinder from the front had oil on the plug engine side; ran really rich)
-change the oil/filter (used 5w-30 Mobil 1 - Apparently, thats the wrong weight for my car...) and I checked the stick when I did the change, and it was in the right level, but checked it again after tonights backfire/roughness, and it was a tad over the max level. Also, oil filter debacle, I ordered the supposedly right filter from Bav Auto, and it didn't fit (found out in the middle of the change) and ended up getting a same-size filter as what was in my car when I bought it, so I know it "fits" but I don't know if it's supposed to "fit".

So, my question is, is there anything that I've done so far that may have attributed to the backfire/rough driving? or should I be looking for something else?

[Stevehose]

If you haven't already join e9coupe.com, there is an e3 section over there and since the engines are the same lots of experts to help. Your cold running sounds like your chokes are not functioning, and the backfires could be fuel and or ignition related (vacuum leaks, points/condensor, plug wire mixup, etc). You'll need to post if your carbs are stock Zenith or have been changed to Webers and if you are running points or Pertronix.

[davidmontgomery]

Thanks Stevehose, I've joined, but have absolutely no privileges there. Dunno if I need to email an admin?

[Stevehose]

Yes, send them a note, they will get you fixed up