Sutty2006 Posted January 27, 2023 Author Share Posted January 27, 2023 I’lll give it a go, but I won’t be able to plug into the ECU with it being so old. so, with the ICV disconnected and idling at 1750/1800 rpm, I disconnected the coolant sensor switch? by the thermostat…. The idle came right down again and ran rough. Then I plugged it back in and it proceeded to idle at 1800. the way this is going I might have to put a restriction in the hose. Quote Link to comment Share on other sites More sharing options...
Sutty2006 Posted January 27, 2023 Author Share Posted January 27, 2023 The Haynes manual is better off on an open fire. wiring diagram for 1986 models doesn’t appear to have “idle control valve” or anything similar. It has idle switch, cold start switch etc. nothing in any of the fault diag sections. All the coolant section refers to is the gauge sender unit, so it’s no help at all. Quote Link to comment Share on other sites More sharing options...
cam.in.head Posted January 27, 2023 Share Posted January 27, 2023 you may have an early manual.mine is number 480 and the revised idle air system is in the supplement at the back circa page 228-229. when you unplug the temp sensor the idle will go haywire as the ecu thinks the engine has gone cold and will flood it. worth checking you have the correct sensor fitted as the symptoms seem very strange. glad to hear there is no corrosion or water in the ecu plugs and footwell sides thou.thats a good find !. if you cannot get the idle air system working fine you could remove it and meter the air but then it would probably idle too low from cold.there is something amiss somewhere. unplugging the valve wont show anything up as the valve will just stay in the position it was last driven to. i have this system on my carlton and cav 2.2 and it all works as it should so its either a adjustment issue or a faulty ecu. i would happily try it in my car for you if you want. its not unheard of for them to go faulty. ive had 2 go in mine over the years. Quote Link to comment Share on other sites More sharing options...
Sutty2006 Posted January 27, 2023 Author Share Posted January 27, 2023 19 minutes ago, cam.in.head said: you may have an early manual.mine is number 480 and the revised idle air system is in the supplement at the back circa page 228-229. when you unplug the temp sensor the idle will go haywire as the ecu thinks the engine has gone cold and will flood it. worth checking you have the correct sensor fitted as the symptoms seem very strange. glad to hear there is no corrosion or water in the ecu plugs and footwell sides thou.thats a good find !. if you cannot get the idle air system working fine you could remove it and meter the air but then it would probably idle too low from cold.there is something amiss somewhere. unplugging the valve wont show anything up as the valve will just stay in the position it was last driven to. i have this system on my carlton and cav 2.2 and it all works as it should so its either a adjustment issue or a faulty ecu. i would happily try it in my car for you if you want. its not unheard of for them to go faulty. ive had 2 go in mine over the years. I have two copies of the 480 manual. I’ll have another look at it. I’m currently talking to another friend who has a 2.2 CDi auto and he’s checking his parts box for spare ecus, if he has no joy, I’ll send you mine to test. edit. I see that in the Haynes manwell now on page 228. When I get my multi meter back from work I’ll test the wiring from the ecu to ICV. That won’t be till next week now. Quote Link to comment Share on other sites More sharing options...
cam.in.head Posted January 28, 2023 Share Posted January 28, 2023 as i said ,ive had a couple of faulty idle ecu's. they looked perfectly fine even inside but wouldnt regulate the idle speed. its a simple system realy when you think of it. same as a 2 litre basically with a variable air bypass to regulate idle. much the same as later motronic cars did. see if your mate has any bits to try . and wel go from there. your unit is at least the correct one for an auto .0280220018 manuals used a different 0280220017 which will physically fit and work fine (just sets the idle around 750-800 instead) your main ecu (just to be sure )should be 028000326 and your ignition advance ecu(by ns strut top) 0227921006. Quote Link to comment Share on other sites More sharing options...
cam.in.head Posted January 29, 2023 Share Posted January 29, 2023 also . check to be sure that even thou the throttle position switch is clicking ,check it actually works ! the terminals i think are marked 2 18 3 ? throttle closed should have a circuit across 18-2 this is the signal that tells the idle ecu to do its thing ! throttle fully open should have a circuit actross 18-3. im going to check mine today because mine OCCAISIONALLY idles at a faster speed recently ? ? diagram at bottom of page 229. 1 Quote Link to comment Share on other sites More sharing options...
Sutty2006 Posted February 2, 2023 Author Share Posted February 2, 2023 I put a restriction into the ICV inlet pipe today. Cost of temporary fix? 1p. I drilled a 5mm hole through it and my cold start idle is a more manageable 900-1000rpm. something tells me that either the ICV is opening TOO much, via a faulty signal from another component, or the ICV is faulty. 2 Quote Link to comment Share on other sites More sharing options...
cam.in.head Posted February 2, 2023 Share Posted February 2, 2023 when i checked mine the other day the throttle switch wasnt always giving a circuit.opened it up to find oil inside it. new switch ordered and ready to go in. mine works perfect virtually every time but there was the occasional time when it wouldnt come down until you blipped it ! when i checked mine the other day the throttle switch wasnt always giving a circuit.opened it up to find oil inside it. new switch ordered and ready to go in. mine works perfect virtually every time but there was the occasional time when it wouldnt come down until you blipped it ! your way will work some of the time but if the valve isnt being operated / no power to it then it can close on its own and bring the idle too low. pity you wernt nearer to me .we would have had this sorted for sure . Quote Link to comment Share on other sites More sharing options...
Sutty2006 Posted February 2, 2023 Author Share Posted February 2, 2023 When it was running at 3500rpm, blipping the throttle lightly would bring it back down to idle but then straight away increase back to 3500. The only way I could get it to stay lower was to tap the throttle. Too much and it would pop and bang through the inlet side like it was dumping too much fuel in. Quote Link to comment Share on other sites More sharing options...
cam.in.head Posted February 2, 2023 Share Posted February 2, 2023 theres definately something amiss there then. and popping etc wouldnt be caused by the idle ecu or valve. if you ever want to send me bits to try on mine for you thats fine .otherwise i can write you a step by step guide on setting it all up from scratch. trouble is ,you dont know who or whats been done / changed/ messed with before. obviously you will no doubt have other bits on the car to work through before its all finished but let me know if you want any other help/ info. lie i say its a pity youre not 5 minutes away. Quote Link to comment Share on other sites More sharing options...
Sutty2006 Posted February 3, 2023 Author Share Posted February 3, 2023 8 hours ago, cam.in.head said: theres definately something amiss there then. and popping etc wouldnt be caused by the idle ecu or valve. if you ever want to send me bits to try on mine for you thats fine .otherwise i can write you a step by step guide on setting it all up from scratch. trouble is ,you dont know who or whats been done / changed/ messed with before. obviously you will no doubt have other bits on the car to work through before its all finished but let me know if you want any other help/ info. lie i say its a pity youre not 5 minutes away. Once I’ve got it on the road I might have a run up to you in the spring one weekend. It’s not like you’re the other end of the country. It’ll be something simple I bet! Quote Link to comment Share on other sites More sharing options...
cam.in.head Posted February 3, 2023 Share Posted February 3, 2023 no worries. Quote Link to comment Share on other sites More sharing options...
Sutty2006 Posted February 3, 2023 Author Share Posted February 3, 2023 Have a picture of it. Hopefully get it ready for mot soon. Quote Link to comment Share on other sites More sharing options...
cam.in.head Posted February 3, 2023 Share Posted February 3, 2023 very very nice . mines the same but in carnelian red (like in the vx brochure) owned since 94. 1 Quote Link to comment Share on other sites More sharing options...
Sutty2006 Posted February 3, 2023 Author Share Posted February 3, 2023 I’ve had two this colour now, and a red one but it was more like a shiny rust colour. With a brown interior. 1 Quote Link to comment Share on other sites More sharing options...
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