Car occasionally loses power over hard bumps.

[shortdog6]

Recently on harder bumps my E30 will lose power - it almost seems like fuel is being cut. It has happened on several specific bumps that I drive through everyday for work, but only started happening recently. This also causes the check top panel light to come on. I'm assuming it something electrical, has anyone had anything similar? 1989 325is

[rwh11385]

Check your battery connections / grounds. That is what happened twice to me.

[ADEN]

Yes, loose wiring probably ground.

Took me months to find out voltage drops from time to time then test all grounds seem solid clean them, still voltage drops then one time took out the ground wire under the expansion tank driver side it looked ok i put my multimeter in continuity mode and it beeps and started flexing the cable side to side left right left right then the beeping stops on the right and beeps on the left, Some old atf oil leaks got inside the lug, no budget at that time to buy new one i put the cable in gasoline for 10 mins then i hit the lugs with a hammer and test it ok put it back, now 6 months with continuous 14 volt charging.

[tomstin]

Loose power as in engine power or electrical (lights dim or blink) or both? I'll second checking all the grounds. If only engine power, I would suspect the ground cable under the alternator. But clean and check all the positive and negative (ground) connections. Even the big group on the steering column.

Have you done any work to the car lately?