Please let it be something cheap!! More parts again!!

[Andyh-R6S]

I replaced the Lambda sensor a last week with a new one and although I have seen better MPG by quite an amount, I did notice that the idle was high, after the Lambda sensor change out!! Anyway I disconnected the battery over night, as I had not disconnected the battery when I changed the lambda sensor, so it had no chance of resetting its values, etc. But the idle was still high.

Anyway, went shopping this morning all appeared OK until about 3o min’s ago when the idle got higher and higher. (If you exclude the kangaroo motion coming out of the supermarket)

a. When I shut the engine down on arriving at the supermarket the idle was high, circa 1400rpm. (800rpm (ish) when I left home)

b. Did the business in the supermarket, I got in the car with my son and then got the kangaroo motion, as if the throttle position switch/potentiometer was disconnected (Been there before!!)

c. Stopped the car and had a look under the hood and all was OK I disconnected the throttle position switch connector, all looked OK, plugged it back in and off I went. (No kangaroo petrol this time)

d. Came to the first traffic lights and the idle was high again. Stuck my shoe under the accelerator pedal and pulled up and the idle dropped. (First clue)

e. Got home and had a good look at the throttle position switch and the cable, etc. Most definitely the micro switch is not making at idle all the time and it is very slow to set back to its normal idle position. (Explains the kangaroo petrol)

It looks like it is either the throttle cable is on the way out, the throttle position switch is on it way out or generally the linkage is starting to seize up, or and hopefully not all three together.

I will take the throttle cable to bits this afternoon and see if it still does it, that should be the cheap bit if its had it, I hope. Other wise a new throttle pot will be needed and maybe new bushes, etc. (Might as well rebuild this area in full!!)

With all the new bits it’s had recently, I was hoping for some cheap motoring (Cheap a cheap could be with this type of car!)

[Rusty]

A few thoughts:-

• Have you tried cleaning the Idle Stabiliser Valve (ISV)? Remove it and use carb cleaner until dirt stops coming out.
• Other thing to do is clean the Throttle Body in case there is some dirt in there that's stopping the throttle butterfly closing properly.
• If the throttle cable is not loose at idle then it could be opening the TB a bit... You can adjust the cable tesnion where the sheath attaches to the TB.

[Andyh-R6S]

Throttle Cable

I cleaned out the ISV a few weeks ago (Yes it was full of crap) however, I have just disconnected the throttle cable and when I manually actuate the throttle linkage mechanism it all moves back quite quickly and you can hear a click from the throttle position switch. Connect the throttle cable back up again and the throttle position switch does not reset and no click can be heard unless I push it back.

So it’s the throttle cable.

Has anybody had one of these go defective? Or is it a right hand drive issue, since the cable is above the exhaust, etc.

Anyway hopefully this will be cheap!!

[gedu]

Well, I know of one UrS4 that went for scrap as throttle stuck wide open (mind you, quite modified). So yes, your throttle cable might be giving up.