Adrian Williams Posted August 21, 2002 Share Posted August 21, 2002 My 1600 supersport has stopped idling both hot and cold. I’ve reset the ECU by fully pressing the throttle several times but that didn’t cure it. Saturday afternoon the engine was idling as normal, started the car on Sunday and all of a sudden it won’t idle. Throttle stop adjustment screw has not moved but if I hold the throttle open and steady by hand it maintains it’s revs very steadily and doesn’t hunt up and down. Engine runs perfectly in all other respects I just have to blip the throttle when waiting at traffic lights and junctions, anyone got any idea what’s wrong? Link to comment Share on other sites More sharing options...
Mr Locust Posted August 21, 2002 Share Posted August 21, 2002 Is this engine fitted with a motorised idle valve like Vauxhall production systems? Link to comment Share on other sites More sharing options...
Adrian Williams Posted August 21, 2002 Author Share Posted August 21, 2002 Don't know, it's a standard Rover mems unit with a supersport map. Link to comment Share on other sites More sharing options...
Mr Locust Posted August 21, 2002 Share Posted August 21, 2002 Sounds like a problem with idle valve (if fitted, I am not familiar with K) or an air leak beween the metering unit and engine. Link to comment Share on other sites More sharing options...
Peter Carmichael Posted August 21, 2002 Share Posted August 21, 2002 It does sound like the Idle Air Control Valve (IACV). These can stick. Between the plenum and the cam cover there is a multi-plug connector. This is attached to the IACV. A pair of rubber hoses bridge between the filter side of the throttle body and the plenum side, via the valve. You can remove this to inspect and clean anything obvious. Can I check your ECU resetting procedure: 1. Ignition on, engine not running 2. Exercise from zero throttle to full throttle and back again slowly five times. 3. Switch ignition off 4. Ignition on, start engine. Link to comment Share on other sites More sharing options...
Adrian Williams Posted August 21, 2002 Author Share Posted August 21, 2002 Thanks Peter I'll have a look at the (IACV) and see if it's sticking. My ECU resetting procedure is as you describe. Adrian Link to comment Share on other sites More sharing options...
Mr Locust Posted August 21, 2002 Share Posted August 21, 2002 If the valve is sticky, use an aerosol 'carb cleaner' type product to get rid of any black gunk. An old toothbrush can also be quite useful Link to comment Share on other sites More sharing options...
JonP Posted August 21, 2002 Share Posted August 21, 2002 Sorry thread hijack attempt... Peter, Does the MEMs ECU have a non volatile memory for the throttle position? ie if you have a battery cutout switch (which I assume disconnects the MEMs 12V feed too) do you need to recalibrate the throttle pot before you drive everytime??? It would appear that the MEMs box might retain the data for a short time (ie 24 hours) but after this suffers brain fade. If I drive my car regularly then the idle speed control works fine, but if the car is left for a week then it seems to have more trouble sorting itself out. I tried cleaning the control valve too. PS my MEMs is an early VVC box BTW. Thanks JonP Link to comment Share on other sites More sharing options...
pie_boy69 Posted August 21, 2002 Share Posted August 21, 2002 This happend to me on my first 1400K supersport and it turned out to be the throttle postion sensor the little black unit on the side of the butterfly, Don't know if this is what you are calling the IACV or not. *cool* *eek* *tongue* *thumbup* Link to comment Share on other sites More sharing options...
pie_boy69 Posted August 21, 2002 Share Posted August 21, 2002 This happend to me on my first 1400K supersport and it turned out to be the throttle postion sensor the little black unit on the side of the butterfly, Don't know if this is what you are calling the IACV or not. *cool* *eek* *tongue* *thumbup* Link to comment Share on other sites More sharing options...
Peter Carmichael Posted August 21, 2002 Share Posted August 21, 2002 The throttle pot is a wear item, but should only be used to give the ECU information on transients. The mapping is done against manifold absolute pressure, which is passed to the ECU down a vacuum hose and fuel trap mounted on the scuttle. Normally for somthing like a 1.6K I can plug in my Emerald ECU and a laptop to diagnose the senders. This at least verifies the "garbage in" side of the problem. Link to comment Share on other sites More sharing options...
charlie_pank Posted August 21, 2002 Share Posted August 21, 2002 Reset procedure for my K (according to previous owner) is switching immobiliser on and off by hand 4 times. Am I confused?! Kermit the frog (when you see Y68 YBP you'll understand) Link to comment Share on other sites More sharing options...
Peter Carmichael Posted August 21, 2002 Share Posted August 21, 2002 That is the reset for the immobiliser. Link to comment Share on other sites More sharing options...
CHRIS CLARK Posted August 22, 2002 Share Posted August 22, 2002 Charlie. The reset for my old MEMS unit was (having had the unit disconnected) to turn the ignition on but not start eng. The throttle pedal was then pushed fairly slowly three (maybe it was four?) times from fully closed to fully open position and return. After that there was a whirring and clicking in the engine area as parameters were reset. Turn off ignition, then start engine as normal & it all performed fine again. Clamshell Club Founder Member. Link to comment Share on other sites More sharing options...
Adrian Williams Posted August 23, 2002 Author Share Posted August 23, 2002 Many Thanks to Peter and Mr Locust it was indeed the IACV. Ten minutes to fix with can of carburettor cleaner and a cotton bud, engine is now idling perfectly. Link to comment Share on other sites More sharing options...
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