loses power

[Feyrerm]

Here is an interesting one. 1984 BMW 733I

Car starts and runs fantastic... for about 30 minutes. After that it will stumble and have no power. I can turn off the ignition restart the car immediately and it runs great again for a few minutes until the issue reoccurs.

Some other possible symptoms. Car seems to idle at 1100 rpm all the time and will diesel on shutdown.

Parts new: Pistons, coil, plugs, wires, distributer, Speed and reference sensor, nearly all vacuum hoses in the engine bay, O2 Sensor, battery, water pump, thermostat, fuel injectors, single fuel pump mod completed.

Car came to me with no cat, just universal muffler.

I do realize new parts don't mean they work properly :-) I just have no idea the order to start to try to test to figure out where the problem is.

I have done a full cleaning on the AFM as well.

I just rebuilt the entire engine and I'm terrified the thing will overheat again. The temp never touches half on the gauge and I use a laser temp gauge on the block that reads 209 or so at the hottest I've seen. I think this is normal but if its not let me know as well.

Hopefully I can figure out this issue so I can enjoy driving the car. I absolutely love it! And when it runs well its a blast to drive.

Thanks in advance for the help.

[Feyrerm]

I think it's possible I figured it out.

I was having a sporadic fueling issue and did some grounding and rewiring to fix that. I also replaced the new Coil with a better quality one.

Car now idles at a lower RPM and does not diesel on shutdown. I have not been able to make it loose power again just yet. It's possible this little bug may be resolved. I will be doing a bit more driving tomorrow as I continue to work the bugs out.

AC is ice cold so theres that :-)