High Idle

[donatien]

Probably a common question here.

Intermittent thing - in traffic or at a stop, clutch down and engine stays at about 1,800 - 2,000 on idle before settling to normal after 5-10 seconds. If I let out the clutch a bit to biting point revs drop and then stay down.

Is this the old stepper motor or a rough throttle linkage? The factory cleaned out the stepper motor 2,500 miles back at the 18,000 service and said it looked ok.

Ta

[GreenV8S]

Is this the old stepper motor

Most likely IMO and worth checking first, although it could also be a faulty road speed sensor, or some other sensor fault causing the ECU to drop into 'fault' mode.

Cheers,
Peter Humphries (and a green V8S)

[Paul V]

Mine had the same problem, Peninsula cleaned the stepper motor but it didn’t make any difference, in the end they changed it for a new one, that seemed to do the trick!

[zippy500]

I had to renew mine also, about 90 quid. Ceaning cured the problem for about 100 miles, all ok now though.

[donatien]

Cheers chaps.

Driving home tonight - no real bother. Well it hovered at 1,500 once at some lights but only for a few seconds. It seems worse when it's been fully warmed up, had a blast and then stop/start for a while.

Is it easy enough to clean this stepper motor or even replace? I've got Steves book and I'm adequate rather than tasty with a spanner.

DT

[apache]

it'sa doddle, at the rear left of the plenum theres a big plastic nut with an electrical connector on it, unclip and disconnect the connector, unscrew the nut, it will have a metal cone shaped insert and spring, clean with toothbrush and WD 40....I bet carb cleaner would work too. Onl thing to watch out for is overtightening on refit as it is a big plastic nut needing a big spanner. I have noticed on mine that if I am coasting with the clutch disengaged the revs hover around 1300 but drop to 1000ish when I come to a full stop......something to do with the roadspeed sensor I guess

[onny]

I'm having trouble with my idle but its caused by speed sensor/intermittant speedo problem. Can anyone tell me where the senor is for my 94 Griffiths 500 with a rover gear box. Is the sensor easy to get to and clean/check?

[shpub]

Unless you have access to an oscilloscope and can see the waveform generated by the sensor which means yurning the wheels and can follow this through the wiring to the ECU input... NO it is not easy to check. Usually on the diff with a TVR slotted disc.

Steve
www.tvrbooks.co.uk