[94 SSE] ABS pump goes on causing engine trouble

[Mcmaker]

It happened while driving from work, ABS pump went on and engine started to run on maybe 3 cylinders. When I hit that vibrating brake pedal the issue goes away and engine runs smooth.
The problem appears 2-3 times per 10 minutes of driving.

I tried pulling off ABS pump and ABS relay fuses, and then I had almost no brake support from servo.

I also noticed weakened brake force and air cushion (even before that problem) when hitting brake and it starts to brake properly only when that pfshh sound goes away.

Checked all the underpressure lining from servo to wherever it goes and it seems fine.

I have no idea what to do.

[redfury]

I'd disable traction control if you have it.

[Mcmaker]

Is there any other option for disabling it than pressing "traction control" button? I didn't noticed any improvement when I turn it off by button, but i'll check that option once again.

[KM AXer]

I'm recalling something similar with the SSE.
While I don't think it had any effect on the engine's running, the ABS would activate during a normal stop, and even go to "ice mode". Had to use the parking brake a couple of times to keep from running into another car... Scary!
My solution was to pull the main ABS fuse (30 A?) under the cover at the back of the engine compartment.

That took care of the recurring problem, but of course there was then no ABS or TC. Then the car was wrecked by my son.... Not having those systems functional certainly could have been a factor in the Michigan snow.

Anyway, not long after we rebuilt the front end of the car, it blew out a brake line, due to corrosion. I set about replacing all that had any sign of weakness. I pulled the ABS unit from my parts car, and stripped it as much as possible. As you can imagine, it was every bit as dirty inside as it was outside. I flushed the hydraulic areas, cleaned all electrical connections and components, and put it in the car when I finished up the lines.

Bleeding the system was a true PITA. But when that was done, I reinstalled the ABS fuse, and both TC and ABS systems have worked ever since. It should be noted that near the same time, I also replaced all 4 wheel bearings. Those have integral wheel speed sensors.

What seems odd about your situation is the diminished or poor engine function. In the '93, when the TC activates, I don't recall it causing any reduction in power, it just selectively activates the brakes to send drive to the non-slipping front wheel. Perhaps that is different for the '94?

Funny that your problem goes away when you push the brake pedal.
I'd be thinking in the direction of some hydraulic shortcoming, like air in the ABS pump itself, or an electronic issue, like a faulty WSS or connection.

[Roadrunner]

Also ... maybe leaking booster diaphragm?
Vacuum leak would affect engine and cause stiffer pedal.