Hi there

Just thought i'd ask on here about a little problem my dad has with his rover 416.

Basically the engine doesn't seem to like slowing down. Sitting on the drive, if you rev it it picks up fine but then takes ages to come down to idle. It'll come down slowly, stick at a few rpms, say 2000 and 1500 or thereabouts, then finally settle to its normal idle. When driving it behaves the same, you come off the throttle and it decellerates really eraticly, shuddering about. When it hovers at certain rpms it's like you've turned on cruise control for a couple of seconds.

Very odd. Any help appreciated. thanks,

Liam

Ours used to do that every now and again. Only once in a blue moon though so never bothered to look into it. Mates Rover was the same as well... Usually when the engine was hot, or if you had given it a thrashing, then when you came to stop the revs would stick at about 2k, then they would drop very slowly.

Never noticed it while driving. Only when stationary.

Not much help I know...

David

British Trident may be the person for you. Suspect dirty throttle housing? try cleaning with carb cleaner

Not too sure about the K series. But sounds like the Idle Control Valve. Should be somewhere on the throttle body, if you have a haynes you should be able to locate it. Take it off give it a good clean with carb cleaner and it should sort it.

A mate of mine is a K fanatic and spent a year at prodrive putting them through their paces, ill see if he knows anything.

[Edited on 17/1/06 by greggors84]

Thanks for the advice guys.

I've got a few bits off and the throttle is closing ok without sticking so i guess it must be the iacv like you say. I just got that off (what a bitch getting to the bottom two screws!). It's certainly covered in soot but I can't really tell how it is supposed to work. I can blow through it easily however i fiddle with the valvey bits inside. Should this be the case or should it be closed with no power? Maybe the valve is buggered? Well i'll soak it in carb cleaner for a while and see what happens.

Cheers

Liam

Might be worth resetting the ECU/ Thorttle Position sensor....

In the seven, you turn on the ignition and slowly push the throttle to the floor and release 5 times......

Only a thought! And, it's cheep!!

sound like the old throttle body syndrome i believe they are made of plastic and eventually warp could need changing there are some alloy ones out there but they are quite expensive

Not much to add to all that except if it is the older type ECU with the MAP sensor built in give the capilary pipe a good clean out. Cars with MEMS 3 don't have this the map sensor is mounted on top of the manifold however most likely it is the idle control valve.

Rover plastic throttle bodies do distort but usually because the throttle cable has been over tensioned -- best to leave a tiny bit of lost motion when the pedal is flat to the floor.

If it is the throttlebody almost any Rover K16 1.4, 1.6 or 1.8 but check you don't buy one for the 72ps 1.4 engine -- as it had limmited throttle openning to restrict the power from 104ps.

The other thing that can cause increased idle speed is the pressure switch on the power steering, this signals to boost the idle speed for slow speed parking when the load of the power steering pump might cause the engine to stall.

Don't be tempted to try and adjust e throttle stop as screwing it back can actuall cause the opposite effect from that intended because the ECU tries to counteract it by moving the idle valve.

[Edited on 17/1/06 by britishtrident]

Thanks for the replies...

After a good clean of the idle control valve and throttle area, it seems to slow down and return to idle properly. Now just gotta find the 2000ish rpm resonant exhaust rattle.

Cheers

Liam