1991 BMW 735i Strange Idling/Power Loss

[BlueE32]

I have a 1991 BMW 735i.. I am having a series of very strange events happen to my vehicle.
It all started when I took a 200 road trip. After approximately 100 miles (going up a hill) I heard a sudden clunk and my check engine light came on. It began to studder and idle strange with no power. No fluids leaking or burst lines.. I had it towed. Let it sit for a day then drove it around for a week with no further issues.

My second incident happened on my way back home. Same road trip. About 150 miles in this time same exact issue- Check engine light came on, loss of power, strange jerking and idling. I let it sit again for 30 minutes and barely made it home.

My third incident was driving around the block trying to pinpoint exactly what was going on - Now after the car has been sitting... If I drive it around the block (1 mile) the check engine light comes on after 1500 RPM and goes off after I release the gas. After trying to order a mass air flow sensor for weeks now to no affail I am at a loss... Im open to any suggestions..
Could it be my cats failing? O2 sensor?
Why is it to intermitten?

I am fairly handy myself and can do most repairs but I have heard this car (E32) cannot use a code reader and I have also tried to do the stomp test with no results..

[shogun]

I will move this thread from the general BMW mechanical help forum to the E32 subforum.
First of all check all the vacuum hoses http://www.nmia.com/~dgnrg/hose_map.jpg
Set the OBC to volts and see what the voltage is when this happens, how to http://bmwe32.masscom.net/johan/obc_...c_secrets.html
Try again the stomp test. sometimes difficult get get the right timing https://www.bimmerforums.com/forum/s...e-pedal-faults

I assume it is not the cat or a O2 sensor.
Also check the fusible links under the rear seat https://www.bimmerforums.com/forum/s...2-fusible-link
Do you have the possibility to check the fuel pump pressure and flow?
Check distributor and distributor rotor.

[CroughtonE32]

If you end up needing an Air Flow Meter, they can be had. They're rebuilt by BMW and sold over the counter or from ECS Tuning and other places. The new part number is

13621466349

Also you can read here. I've been looking into this place in Ca that rebuilds yours for less than a 200 dollars. They have a long turn around but I've heard good things. Read their process.

https://bavrest.com/air-flow-meter-service.html

[theBMWbeast]

The prices on these jumped. I just looked at FCPeuro, $410 +75 core for the exact same unit I payed $150 a few months ago! Bavrest is probably your best bet now.

[CroughtonE32]

The prices on these jumped. I just looked at FCPeuro, $410 +75 core for the exact same unit I payed $150 a few months ago! Bavrest is probably your best bet now.

You know I was thinking (money aside), that FCP and others that we buy parts from, as well as over the counter at BMW dealer might just clean them up, make sure the voltages are correct paint them and send them out. I like the BavRest explanation of exactly how they rebuild. The bit about making sure the wiper of the Potentiometer touching only fresh metal when they're done, Oscilloscope readings sent out with the part after rebuilding. Adjusting the spring on the flap to factory settings. Just seems that you're getting a good rebuild if they actually do what they say. Just thinking out loud here.