M20B27 issues

[GRIZZLY69]

Hey all,

I have a 85 325e that's running poorly. The idle is rough, it shakes the hole car and then suddenly yesterday the car wouldn't idle at all. I cranked it on and it turned over and died right there. I was only able to get home by giving it gas at all times. Then as I drove the car was fine accelerating or decelerating but if I kept at a constant speed the car would jerk real hard. Only way I can describe is imagine being in too high a gear and you get that jerking motion that's what it felt like at 65 on the freeway. My first thoughts are spark plugs and fuel pump? Any ideas welcome!

Thanks

[Kershaw]

Do a smoke test for vacuum leaks.

[GRIZZLY69]

Will definitely try that.

[Bggdnssnguy]

Okay so I can't post my own thread yet. But just bought a 89 325i.
Idles around 1000 rpms and when it's in park the brake pedal is nice and hard. But as soon as it's in drive or reverse the pedal goes to the floor. Like it has no vacuum under a load. Where would you plug a smoke tester up ideally to smoke it? I'm a Nissan tech and all I know is Nissan, so this BMW I bought for dirt cheap is kicking my tail. Any help is appreciated.