A Quick Tune Up?

[racerxx]

Hi All,

I'm looking for the cause and hopefully quick remedy of the following problem.

My '73 coupe has recently (month or so) started running a little rough. When going around turns at low speed it tends to slightly buck and sputter. And when I drove it yesterday it really began to run rough, while running down the hi-way at 4,000 rpms the engine would miss a little and rpms would drop. It also idles very rough from standing starts.

Consider it has not had a tune up in 2 years, it sits in a garage all winter and I only drive it 3,000 miles a year. Also, it has never had work done to the engine (currently has 90K miles) and it needs an upper engine rebuild. While driving fast and letting off the throttle it emits a nice gray fog.

I think the plugs are fouled and maybe needs the carbs (Zeniths) cleaned or adjusted (?). I was planning to check into this weekend and was wondering if I should consider anything else. Bear in mind I'm not a master mechanic with tons of tools. However, I have changed an engine and a head or two in my day many years ago.

Any insight or advice would be greatly appreciated, considering I plan on taking it to Lime Rock on Labor Day weekend and don't want to be pitied by some guy in a Bangled Butt (ugly) 5 series.

Best, John Raho - Westport, Connecticut

 

[shanon]

try this:
new spark wires, cap & rotor and fuel filters.
this is a simple afternoon project that could clear some things up or at least eliminate some variables.

if that doesn't do it, take to your shop and wave the magic wand.

HTH.

-shanon

 

[pj]

Shanon , didn't you mean "The Magic Wad ".

PJ

 

[jhjacobs]

The basics already suggested are a reasonable plan. You might also try:

- Add bottle of gas line dryer to the tank in case your light use has allowed water to condense in your tank (or you simply got bad fuel). When turning water is more likely to flow into the jets and cause sputtering.

- Add points and condenser to the list - I recently had a defective condensor that took be forever to figure out. It would cause the engine to run rough and periodically stall. Of course you will need to set the point gap and re-time the ignition if you change the points. It's also fun to go the a local parts store and ask the kid behind the counter to look up points - he will be completely baffled by the request. Actually, I would recommend buying them on-line; they are easy to find and less expensive than at the BMW dealer - either way you most likely need to order them. Napa does carry points for the Bosch distributor but they are very different from the original Bosch points and I've had mixed results with them.

- If you get really inspired buy a Crane optical ignition kit (about $100). After my defective condesor episode I made the switch and my M30 has never run smoother. It took me about 2 hours to install mine only because I made a nice mounting bracket. If you want to make such a conversion and would like more details let me know. I can send/post photos and notes.

- My final advice is what my BMW dealer in Vienna, Austria, told us in the early 70's (loosely translated from German): "go out and run the snot out of the engine for a while and it'll get better." There is actually some merit to this. The coupe and 2002 engines are very prone to severe carbon build up on the intake valves. Running the engine hard for a while can often break it all loose; it leaves in a cloud of smoke. Of course, this is also a good way to kill you r engine so be careful!