320i kangaroos sightly

[Retrespect]

Hello,
This is my first post as the proud owner of a 1989 e30 320i.

Loving it so far. However, when I drive a long at a constant speed or sometimes when I let off the right pedal, the car seems ot kangaroo slightly for a while. I can either drive through it, accelerate or press the clutch down to correct it.

Does anyone have any idea what this is? Could it be linked to the clutch master slave cylinder?

Thanks

Chris

[Reflex]

could most likely be an AFM problem, replace it

[Retrespect]

Thanks, any idea of the cost fitted? is it easy to do myself?
Cheers

[toby]

It could be but check your plugs, rotor arm and distributor cap first.

Which engine and what age is the car?

[Retrespect]

its a 1989 320i.
It seems fine 70% of the time, but then seems to take on a mind of its own unless I press the clutch (even slightly) or accelerate

[toby]

Check the basic bits first. It sounds likely to be ignition related.

Check the plugs are clean. Then distributor cap is under a black cover held on by three bolts



If you are standing and looking at the engine as above, the black cover (just here^) over those wires follow the HT wires from the spark plugs, remove that and check the rotor arm inside isn't starting to break up and the contacts inside the cap and on the rotor arm look clean.

These photos are from another site;

[E30BeemerLad]

do the revs fluctuate up and down when it ticks over?

[Retrespect]

very helpful, thanks Toby.
BeemerLad, the revs are generally good. I've had it a week now and once when I started it the revs were all over the place. Generally the rev needle sits nicely but there is a slight variation in the sounds of the revs when idling.

[E30BeemerLad]

Reason I asked about the tickover is that I had a similar problem once on my 325. On constant light throttle, say 40mph constant in 4th, it would kangaroo and jerk, making me look like a right spesh. The revs also hunted up and down at idle.

It was the inlet manifold gasket, diagnosed by having the car sat at idle and spraying the inlet manifold around the flange where it bolts to the head, sprayed all along where the bolts are and the idle briefly smoothed out for a few seconds, because the leak had been sealed by the WD40.

It is worth checking all the vacum hoses for splits and proper sealing where they go into the throttle body housing. Also take off the rubber boot that goes from the air flow meter to the throttle body and check that hasn't got splits.

[toby]

I'd agree with BeemerLad and replace and split hoses.

If you've only had it a week, get it properly serviced and this may sort out a lot of niggles.

[Martinaston]

Do a search on here for "kangeroo" then get comfy and have a read.
The list is loooonnnngggggg.

[Retrespect]

Thanks guys. I'll do some digging and let you know.