My '78 320i was running great, and now all of the sudden the car is getting very sluggish after driving it for just a few minutes. Under full throttle, or just after cruising a few minutes, the car starts to feel like someone has strapped a rope to the back of the car and is making quick jerks back on the car. The problem gets worse and worse with time until finally the car just starts slowing down and there is nothing I can do about it. The problem will fix itself if I turn the engine off and back on again (which luckily I can do at 60 mph). Please let me know of any ideas for a fix.

Thanks in advance.

might be way off, but have you tested your alternator / battery?
i cant imagine it starting again afterwards if it was getting that flat, but it might be worth a look at.

might be way off, but have you tested your alternator / battery?
i cant imagine it starting again afterwards if it was getting that flat, but it might be worth a look at.

I can't imagine that it is the battery, it keeps turning the engine over to start over and over again. Especially when the car gets so bad that it doesn't want to start from a stop.


I'm now thinking that it might be a distributor cap/rotor issue. Anyone know any good diagnostics to check the distributor?

I would say check your timing. I know timing can make a HUGE difference in how sluggish the car feels, but I don't know why turing the car off then back on would fix the problem.

Sounds like the external fuel pump could be a culprit. Do you here it prime when you turn the ignition on before you start it? Before you start looking at the fuel pump check you're timming first.

if it keeps cranking then no, its not your battery

When was the last time the fuel filter was changed? Your line may be full, but it can't keep up after you get it started. The in-tank pump screen may be clogged as well. Hope that helps!
Tim