Ive got ABS issues

[Kvasi]

A while ago my brakes started something strange. When im driving everything works fine, but when i come to a complete stop the ABS starts acting up. The harder i press the pedal the more the ABS-pump "works" and it also lets go of the brakes as it thinks im driving and locking up.
All sensors have the same OHM and i cant figure out whats wrong..
Any ideas?

Its a -89 325 IX Touring

[Kvasi]

None?

[Sagaris]

I have a similar issue. Occasionally the first brake application will have a very hard brake pedal with no stopping power and I feel/hear the ABS pump running. I have replaced the ABS computer but have not had a chance to drive the car yet. I am really expecting that the problem is something internal in the ABS hydraulic unit.

[browntown]

nevermind, norway is too far away for cheap parts. Try swapping out your abs computer.

[sam3]

Is the ABS light on? Does it stay on or activate only when the fault occurs?

[Kvasi]

No ABS light, or other signs of something wrong. Brakes/ABS works just as they are supposed to when driving.

[jlevie]

This makes me think of a bad ABS module or bad sensors. The sensors could have the normal resistance, but still not be working correctly. Given the symptoms I'd try a new or rebuilt ABS module first.

[sam3]

No ABS light, or other signs of something wrong. Brakes/ABS works just as they are supposed to when driving.

I chased a similar issue for a week, changing components with known good ones, the problem ended up being a wheel speed sensor that tested fine on the Ohm meter but did not produce enough voltage when the wheel was turning. Hook a multi-meter to the sensor and measure the voltage as someone spins the wheel by hand, as fast as possible, leave the tire on to get more leverage. The sensors should read around 1v, I had one that produced only .7v which was causing the problem. I have seen the relays under the ABS pump cover go bad as well, though not often.