E30 Engine problems

[EagleOne]

Hi there,

I have a 1988 BMW 325i with 152,000 miles on it. Just recently I have been having issues with a few problems...

Now to start, I have done lots of research on my issues and tried a few things...

I have checked all vacuum hoses for leaks, including problem areas such as the oil filler cap, dip stick o-rings, gaskets, etc. Idle is perfectly fine. The idle control valve runs as it should and is well maintained. Not sure about the AFS, but it has been cleaned and all electrical checks out good.

I have replaced the fuel pump with a known good one as well as fuel filter.

Spark plugs were replaced, as well as wiring harness, cap, and rotor. Ignition coil was also replaced.

New K&N OEM Filter.

Coolant levels are good, and mixture is good. No leaks anywhere.

Oil levels correct and all the basic maintenance is up to date.

Ok... Now the issues...

My main concern is when driving, all of the sudden the car will lose power and shudder quickly yet violently. The MPG Econometer, tachometer, and temperature gauge all jump, and the check engine light flashes for a split second. Then the car returns to normal operation as if nothing happened. In some cases the car does this and I watch the tach slowly fall and and the car will down shift until it dies completely. After turning back the key to the off position, then restarting in neutral, it starts perfectly and I can resume driving until it happens again. This symptom is getting worse... But some days it is perfectly fine! As if it has never had any problems.

I should also note my econometer does not register anymore... It's the only gauge that isn't operational. When the car is off it sits above the 40 MPG mark as it should, and when started, it sits at 0 MPG and at highway speeds it moves slightly up to 5 MPG.

The Brake Lining light comes and goes.

I am wondering if the cause of the major issue, the loss of power and dying, is the cause of either the AFS, O2 Sensor, Timing Belt, or something else...

Perhaps the thermostat? My car only receives heat inside the car when it is fully warmed up, and on the road. At idle there is no heat... All the hoses are hot to the touch though, so I do not understand that one.

Any help and advice would be very much appreciated!

Thanks,
Travis

[EagleOne]

Check Engine Light Flashed a 1-4-4-4 code which means No Faults... Still have problem though.