Slow down...please

[Toby Noble]

Car: 1984 280i

Symptom: Sometimes recently when I blip the throttle in neutral or am driving and accelerate, the revs stay up and don't come down until I brake while in gear.

Very disconcerting to say the least.

Okay, now you're freaking me out. I may have to rename you "Christine".


When I accelerate and change gear the revs rise as I depress the clutch and come back down as the higher gear engages.

Anybody found and reason other than a bent/frayed/sticking throttle cable that could explain the above?

I've had a look an can't find anything obvious but Steve's book mentions a sensor that can malfunction, although this appears to stop the engine revving if I'm reading it right.


Help or similar experiences would be greatly appreciated

Toby

[rolexblue2000]

have a look under the rubber boot on the metering head. See if the round disk is sticking and check the connection under the plate

Richard

[GreenV8S]

Not owned one of those so this could be rubbish, but my first guess would be a sticking throttle - throttle rubbing on the bonnet insulation, frayed cable, pedal catching on the carpet, something like that? If you can get the engine to do this stationary with the bonnet up you could quickly rule out most of these. I understand that these cars also have a vacuum operated valve on the plenum that lets air in on overrun and stops you getting engine braking (improves emissions or something). If this was faulty it might give the symptoms you're seeing. Could be worth tracking this down (no doubt the Wedge Bible will have pictures) and disabling it to see if it makes any difference?

Cheers,
Peter Humphries (and a green V8S)

[Toby Noble]

Thanks Gents, geez you guys are good.. under bonnet insulation it is. Sagging down onto throttle linkage.

Has anyone; removed/replaced with original/replaced with something else, the insulation?

My insulation is in poor condition and I don't know if it will even stick any more so I need a plan B.

I'm trying to manufacture from aluminium some sort of cover for the linkage as an interim measure but it won't be pretty, mind you neither would me rear ending some car...........

Experiences anyone?

[danny hoffman]

I fitted a metal plate above the throttle linkage on the 280 to prevent this.

Danny