Rover v8 3.9 v8

[Big woof]

Hi all I'm having some problems with my v8 discovery had a go at setting the base idle on the car then All kinds off things began to happen high revving and not dropping down to 800 rpm when at traffic lights.
Over the last week I have re sealed the stepper motor housing gasket. Plus the plenum chamber top as some one had been in there playing with it. Timing set in accordance with land rovers specs now she will rev normally but seems to be still revving at a thousand rpm when coming to a stop and then drops to 800 rpm after a couple off minutes I've also checked the vacum pipes breather and throttle position sensor.
This car has had just about every sensor and a new ecu just about everything that controls the idle is brand fire new. Just shy off ripping the whole car in bits and fitting a new cam shaft chain and all gaskets I am out of ideas problem only arose after setting the base idle.
Any thoughts any at all what be great fully recived [/b]

[ramon alban]

Hello Woof<

From your description of the classic symptoms, this sounds like a case of "Idle Speed Hangup" generally caused by mechanical interference of the throttle plate mechanism.

You will find a full description of all the issues involved in my PDF essay linked from here:

http://www.vintagemodelairplane.com/pag ... ing01.html

Quote from page 5 of the linked PDF

Whilst this overall discussion and detail applies to the Twin Throttle Plenum as fitted to the
later Rover SD1 Vitesse, specific information related to air leakage, friction in the throttle
assembly and cleanliness of the air intake mechanism may be laterally applied to the Single
Throttle Plenum

If you are able to fix the problem you may find other stuff on my web pages helpful.

Good luck and happy new year.

[Big woof]

Hello Ramon and happy new year to you to managed to sort out my high revving problem. Wrong throttle position sensor changed that and my word it's much better drops the rpm's down as it should do. Base idle set the dizy timing set properly. Top end power is tailing off and is slowly improving over what it used. To be and just the starting problem to sort out and il be happy

[Big woof]

Hi there all I think that I might be down now to a faulty ecu fueling chip. I say this as it will rev above 6 thousand rpm but then other times it can struggle to rev beyond 5200 rpm which the limit is set too.
The only other thing which is controlling all off the engine sensors and things I think that the data might be corrupt or some one has had a go at super chipping the ecu and got it wrong.

[ramon alban]

I think that I might be down now to a faulty ecu fueling chip.The only other thing which is controlling all off the engine sensors and things I think that the data might be corrupt or some one has had a go at super chipping the ecu and got it wrong.

Hello Woof, is this at odds with your earlier observation: -

This car has had just about every sensor and a new ecu just about everything that controls the idle is brand fire new

You seem to have replaced everything and tested very little, a scattergun approach with (presumably) a fairly high cost of replacement parts. Also if some of the parts are wrong and randomly gathered or adjusted, then you may have a collection of mismatched components.

Earlier you mentioned

Wrong throttle position sensor changed that and my word it's much better drops the rpm's down as it should do.

Was this an electrical issue or was the 'wrong' TPS causing mechanical interference as I suggested.

I hope the above observations are not too critical for you, if so, apologies.

Its hard now, to suggest where else you might look, except that the jungle addage might apply - "when you are up to your arze in alligators it its difficult to recall that the original intention was to drain the swamp!

If so, back to square one could be your best bet.

With that in mind, you could consider the 15 point power loss/health plan for Efi RV8 systems on my web pages.

http://www.vintagemodelairplane.com/pag ... ver01.html

Where your machine differs from the original Flapper system, then its fairly easy to adapt the principles therein.

Whatever else, keep the faith.

[Big woof]

Hello Ramon no offence taken mate at all. Any advice is greatfully recived.
Okay yes I can appreciate what you are saying problem has been that some one else has played around with the car and replaced quite a lot off things already. I called land rover got all the part numbers where we knew parts was wrong numbers damaged or just not right for the car. Also I manged to get some stuff old stock some bits are aftermarket that are no longer available any more but plenty after market I have tested all the sensors following the Haynes Manual and also various web sites that give values for the multi meter plugged in to auto logic snap on ethos scanner and rover gauge all of those was saying that it was okay on all the sensors.

Been to various garages and all have said that they don't know much about v8's any more or have moved on to modern technology. So I have been left doing the work myself. The old ecu have up the ghost and wouldn't run the engine don't know what happened to it and had to be replaced as I use the car everyday just when I got everything sorted out and then I opened the throttle to see what happened. The ecu is socketed and should be easy to replace the fuel chip.