E28 Jerking in 4th-5th once off throttle

[thugginrobby]

Another question for my fellow e28 mates.

Just starting driving my e28 again and while in 5th gear just cruising, I let off the gas and suddenly my car almost chokes and starts slowing down. I figure it’s actually the engine braking and not the drivetrain. Only really does this in 4th and 5th gear so anyone have similar experiences?

[Shawn D.]

The fuel is cut when the throttle is closed and RPM is above ~1,100. In contrast to your situation, it has always made my 535i jerky at slow speeds, such as trying to drive slowly in a parking lot.

Try adjusting the idle switch position.

[thugginrobby]

I did, i’m saying when i’m on the freeway cruising, once I let off throttle going like 80mph. The car jerks back and starting slowing down rather fast

[Shawn D.]

I understand you said it was at speed, which is why I said "In contrast..."

It's hard to understand what you mean by "starting slowing down rather fast." It slows down faster than taking your foot completely off the throttle?

[thugginrobby]

Hey, sorry about that. The easiest way I can say it is, once i’m off throttle, the car slows down then theres a slight chuck that happens, which causes the car to slow down drastically faster than it should as opposed to just being in neutral.

[Fedaykin528e]

Sounds like it may be operating normally, typically when I let off throttle there's a clunk because there's some play somewhere in my driveline. Then it does decelerate because it's in gear... a lot of mechanical drag especially in old cars. And it does not happen in neutral?

Unless you're experiencing more like slamming on the brakes - not sure what that would be. You think you could video it?

[RetiredDoc]

The fuel is cut when the throttle is closed and RPM is above ~1,100. In contrast to your situation, it has always made my 535i jerky at slow speeds, such as trying to drive slowly in a parking lot.

Try adjusting the idle switch position.

All these past years I thought it was my crappy driving that caused bucking and jerking at parking lot speeds. The only way I found to control it was to stay in first, use higher RPM and ride the clutch. It’s finally nice to know there is a mechanical cause, though I still don’t understand fully how it works. Thanks.