Dodgy Idlding

[vince n]

Don't know if it is a problem. My 98 450 is fine, all of a sudden I started it for the first time in a week and it reved to about 1800 rpm and would not drop. After about 15 miles I stopped the revs still up on tick over, I then turned of and re started it went back up to 1800 then seemed to sort its self out and went back to 900 rpm on tick over, anybody any ideas what that was about I would be gratefull, Le Mans looms and nothing must spoil that.
Many thanks Vince Narduzzo

[RCA]

There have been quite a few threads on this I think, mine used to do it, First I would clean the idle stepper motor, I did this on mine and it cured it. If not have a look through some of the threads and hopefully someone else might be able to help!!!!!
Good Luck

[zippy500]

I Had the same, stepper motors are the bain of my life. Numerous attempt at cleaning the cursed thing and have now bought a new one. They are about 100 quid so get a dealer to check if its knackered. Mine was very slow apparently. Its very easy to fit yourself so save a few quid and enjoy a bit of DIY if you take the plunge. Also try disconnecting the ECU for 30 seconds. This can reset your system and may cure it. It takes a few hundred miles to correct itself so you may not notice anything for a while. However the stepper motor is probably suspect. If not there are a few other sensors that can cause problems. Road speed sensor is one but I have no experience on this or other ones. Give the stepper motor a clean first. It will help never the less.

>> Edited by zippy500 on Friday 3rd May 07:51

[dpugh]

I have a similar problem. I have had a new stepper motor and new Lambda sensors. The Lambda sensors made a massive difference to the response under 3000 revs and for the most part the car idles fine however every now and the car decides it don’t want to idle at all or just goes a bit erratic.

Any Ideas? How do you reset the ECU?

Dave

[squirrelz]

I had a problem with my Chim 4.0, where every so often, it would fail to maintain idle. ie. change gear too slow and it would stall, or come up to traffic lights, dip the clutch and it would stall.

Joolz cleaned and lubricated the stepper motor, cleaned out the throttle butterfly and did something with the throttle pot. and it's not done it since.

[L10 TVR]

Just took my old dinosaur into TVR dealer to sort out idlding problem and steering fault.

They have sorted the steering problem and now the car drives much better. I'm very happy on that front and very pleased with the service that the dealer has provided me.

However the idlding problem continues, they said that the fault was a poor connection on the engine temperature sensor that was causing the fault. They cleaned the connection and sent me on my way.

It seemed ok for the first few minutes but once I got off the motorway the fault was back.

I stopped on the way home and had someone plug in a fault box which came up with the code 44. Which I am told is the left Lamba sensor.

I spoke to TVR about this and they tell me that they checked the sensor was working and that if it was wrong the engine would run like a pig on one side, which it isn't.

I am tending to believe what the dealer says. What faults have others of you experienced when the sensor was wrong and did replacing the sensor instantly correct the fault.

[zippy500]

Easiest way to reset ECU is to disconnect it at the main lead whichn goes into it.