Idle control valve

[simontaylor]

The MOT staff are only interested in a warm car, so if it only a problem when cold....it wont be a problem by the time you get there. I would guess if you booked it in for an MOT through some one in the know, like Derek, he will know a sympathetic and understanding tester.

Yep. But only problem is I have to leave it with them so it will be cold.

I'm thinking now that it might be the throttle pot and it's not going to idle on the microswitch.

More testing tonight assuming there aren't massive thunderstorms.

[simontaylor]

should be easy enough to test the 3 point microswitch.

[The Saint]

I have a brand new GTA one somewhere in my pile of junk... Not got a GTA anymore so not much use to me!!!!

Hi Darren. The micro switches have a habit of failing. They are standard easy to get items that only cost a few pounds. If you carefully split the housing, you will see how simple it is. I got mine from Maplins , although they’ve gone out of business now. Still should be easy to source.

It’s been covered recently on here.

Bypassed the micro-switches (jumped the contacts with a paper clip) but still the same. 4.8v or so across the two wires for idle. I need to have another think...

Ok so still no joy although I have sorted one thing out. Looks like when we were up at Scoff's the throttle pot wiring was connected back to front. That is to say yellow to yellow, brown to brown. Strangely the throttle pot connectors are cross wired a bit like the TDC sensor - yellow to brown, brown to yellow. This is apparent from the plastic tangs on the connector, but with age the main tab was broken and I guess Scoff wired it the logical way round.

That meant the WOT switch was still connected but the idle switch was disconnected - opposite way round to what Mr Faulks wanted.

Anyway. Regardless of that it's now the correct way round. I thought at this point I had cracked it as it started with a perfect idle of 1200 rpm and dropped quickly to approx 800 once warm. Voltage at the idle control valve was 7+volts at this stage, so much more in the range I was expecting versus the 4v I had been seeing. Stopped and restarted it and all good.

Came back the next day however and I'm not getting a clean steady idle again and back to 4v input at the ICV. I can only think that it's a feed of some sort to the idle circuit, but what and which sensor? When it did idle at 7V it was much better behaved with better pick-up than when it didn't, so I'm thinking it's also potentially not running the cold idle map.

Voltage at the throttle pot is still + / - 4.8V or so across the central pins to the outer ones.

Coolant temp sensor seems to read 300 ohms at cold. Same for the air temp sensor, with about 4.8v or so across the inputs.

Really odd. Again each time I think I've cracked it I try it again and back to the beginning. I even put on a new ICV and same result, which tallies at least with what I've seen from the input voltages and the lower values I'm again seeing......

Bin it and run a Ratty racing mod .........job done ...sorted for maximum shits and giggles....not TPot for maximum flameage dude

Probably wouldn't help with the MOT!

Well the throttle pot switch seems fine. 0 ohms resistance on idle across yellow and black, 0 ohms resistance at WOT between brown and black.

It's definitely not running the cold idle map though, but the temp sender seems ok and the input to that has voltage.

Hi Lee. Did you manage to get any voltages for the ICV pins when hot and cold?

Thanks

Darren..does this help... suggests a way to test..
and 12v

Also the generic operation


And the pins..though you have this 559 is the Idling Speed Regulating Valve (the legendary renault legends omit this..but it is 559 on other models)

All this info comes from the renix workshop repair manual 7711084524
I'll be at home tomorrow working if you are passing drop me a PM if you want to check voltages on my car

Hi Dave. That's great. Would you be around today after work (5pm ish)? If so I'll drop by if you can PM me your contact details.

(I've brought multi meter with me!)

That works ...PM sent.
I do have a Sykes Pickavent reader (never used it!) You are welcome to try that too. Though not sure it will help in your case..
Dave

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