1987 325i Runs Rough Cold

[BeerGeek]

I have an '87 325i convertible (122K). It runs rough when it first starts up, missing and sputtering a bit. After it warms up, it runs fine.
If I start it up and drive to the gas station - 3-4 miles - it will run rough on the way. I shut it off, put gas in it (the car will sit for 5-10 minutes) and start it back up, it runs smooth.
If I don't stop for gas, and drive past the station, it's another 3-4 miles before it smooths out, so it's something under the hood that needs to get hot.
Coil?
Regulator?
Wires?
Distributor?
O2 Sensor(s)?

[jlevie]

That sounds like the result of intake leaks. A smoke test of the intake will reveal any and all leaks.

[blacknbluebmw]

i agree with intake leak. had the same issue with my '87; replacing the intake gasket fixed it up.

[ed]

mine is doing same thing. glad to see I'm not the only one. will check mine too. :)

[jackbaggins]

Replace anything that you don't know the age of, like plugs, some of the upper intake gaskets, check for vacuum leaks, etc. Remember, your car is 23 years old. By the way, it's NOT the o2 sensor as that doesn't come into play until the car is warmed up.

[ApocalypseNotNow]

do basic tests. first on the list would be the low and high temp switches, next test your oxygen sensor. if it only happens when the engine is cold how could it be due to an intake manifold leak? you mean the leak fixes itself when the engine gets hot? :))

[Bill-H]