Loverobot Posted November 20, 2010 Share Posted November 20, 2010 In between gear shfts the revs are dropping very very slowly when pushing the clutch in not all the time just intermittently; Is this a sticky IACV and if so how do I rectify please? --------------------------- Nick Guiseley Link to comment Share on other sites More sharing options...
jj48 Posted November 20, 2010 Share Posted November 20, 2010 Could be IACV or TPS switch. Have cleaned IACV internally before with mixed results. Had a problem on a customers 7 a few weeks ago and ended up replacing both components. Richard Sussex Swede R400 Link to comment Share on other sites More sharing options...
Archie Procter Posted November 20, 2010 Share Posted November 20, 2010 or could be a break in the wiring loom somewhere, or the mass airflow sensor (the plug on the inlet manifold)... These sorts of things can be quite difficult to diagnose correctly without specialist kit. I would check the wiring to the TPS and MAF sensors in the first instance by pulling the plugs out and having a look, if it looks ok and doesn't "hunt" when you give the wiring a shake while plugged in then maybe try a different IACV - they are easy to swap between cars if you could borrow one from someone. If that sorts it you may just need a new IACV. CC don't stock any Rover engine ancilliaries any more so you'd need to source one through a Rover parts specialist. Cost should be IRO £45-£50 unless they've gone up or down since I last bought one. If neither of the above seems to make much difference it's time to call in an expert - I know a very good Rover ECU/electronics specialist; if you would like his details my email address is in my profile. Link to comment Share on other sites More sharing options...
Myles Posted November 21, 2010 Share Posted November 21, 2010 An alternative to check... Sticky throttle-cable? Particularly if your cable gets squeezed under the bonnet...? ISTR that I had an occasional problem with the k-series on one throttle-cable - and it tended only to appear when everything was warmed up. Only way to really check, I guess, is to wait until the problem resurfaces on the road, stop, check it still happens when stationary, remove bonnet and try again. 🙆🏻 🙆🏻 🙆🏻 🙆🏻 🙆🏻 Alcester Racing 7s Ecosse™ 🙆🏻 🙆🏻 🙆🏻 🙆🏻 🙆🏻 Alcester-Racing-Sevens.com Link to comment Share on other sites More sharing options...
Stationary M25 Traveller Posted November 21, 2010 Share Posted November 21, 2010 ... and not just the cable .... check also the pivot bolt on the throttle pedal. Disconnect the cable at the engine end and check both cable and this pivot. Also ... if you have the plastic inlet, check the jubilee clip on the air filter is not too tight ... this can distort the plastic housing and trap the butterfly. Link to comment Share on other sites More sharing options...
Loverobot Posted November 23, 2010 Author Share Posted November 23, 2010 cheers guys will check all the above and see what gives am loving the car esp in the cold with cold tyres lol --------------------------- Nick Guiseley Link to comment Share on other sites More sharing options...
charlie_pank Posted November 24, 2010 Share Posted November 24, 2010 If none of these things help. Try and make friends with someone with the same model as you and borrow their ECU. back here because I want to be. Link to comment Share on other sites More sharing options...
Loverobot Posted April 12, 2011 Author Share Posted April 12, 2011 Sorry to resurrect an old thread but didnt sort this and is still doing it - pretty hairy on the tops in Wales when the revs dont drop on a bend ! Could anyone tell me where the IACV and TPS are so I can have a clean and see if that helps? Any tips re removal etc greatly appreciated Link to comment Share on other sites More sharing options...
Fishy Dave Posted April 12, 2011 Share Posted April 12, 2011 I had the same a month ago, it was a sticky throttle pedal in my case. As SM25 mentioned, remove the throttle cable, take the cover off the pedal box and move the pedal by hand to check it is free to move. Link to comment Share on other sites More sharing options...
Loverobot Posted April 12, 2011 Author Share Posted April 12, 2011 99% sure not the pedal tbh - did check at the time but will recheck Link to comment Share on other sites More sharing options...
wag Posted April 12, 2011 Share Posted April 12, 2011 My EU3 engine used to do that. There is a connector near the air filter which I disconnected and it stoped the problem. Makes mine hunt on tickover. I think there is a thread on this. Link to comment Share on other sites More sharing options...
grumpy the 7th Posted April 12, 2011 Share Posted April 12, 2011 Have you got the plastic throttle body? This is a common problem. Preferably get a 52mm alloy throttle body or slacken the air filter jubilee clip and turn the filter 180 degrees and just nip the jubil;ee clip up. rog Edited by - roger heeley on 12 Apr 2011 16:42:38 Link to comment Share on other sites More sharing options...
Loverobot Posted April 12, 2011 Author Share Posted April 12, 2011 Metal throttle body so assume that slackening the clip wont make a difference? Anything I need to be aware of or look for when dismantling and cleaning the IACV? Have read about a potentially errant spring! 😳 Link to comment Share on other sites More sharing options...
Archie Procter Posted April 12, 2011 Share Posted April 12, 2011 TB is irrelevant, it's either the IACV or one of the sensors, or something in the wiring loom as posted previously. You don't dismantle & clean IACVs IMO (nor in the opinion of the Rover electronics expert I know), you just replace them. Without wishing to sound uncharitable, you had this problem, got advice, did nothing about it and it didn't go away . Well duh. Why would you expect any different advice now? Link to comment Share on other sites More sharing options...
KarlH Posted April 12, 2011 Share Posted April 12, 2011 Not wanting to hijack this thread but I've got a similar problem in that my EU3 1.8 K series idles fast on start up (2000 rpm) and then ticks over at 1500. It will eventually drop but as soon as you're on the throttle it's back up to ticking over at 1500 when you stop. Having looked at this and some other threads I've so far done the following which has made no difference: 1. checked for a sticking throttle cable 2. checked IACV,TPS and MAF plugs and wiggled the cables 3. swapped IACV 4. swapped TPS 5. swapped water temp to ECU sender 6. reset the ecu using that ignition off, 5 times on throttle procedure at after each of the above The only other thing I've read about is the MAP sensor, but given my limited technical understanding I think that basically means the ECU is screwed - is that right? Is there anything else I can try? Cheers, Karl. Link to comment Share on other sites More sharing options...
CharlesElliott Posted April 12, 2011 Share Posted April 12, 2011 Plug it into Testbook or an OBD2 reader and see what the sensors are saying to the ECU. Link to comment Share on other sites More sharing options...
KarlH Posted April 12, 2011 Share Posted April 12, 2011 Plug it into Testbook or an OBD2 reader and see what the sensors are saying to the ECU. I was going to see if there was a local garage with some kind of reader but thought someone told me MEMS readers were few and far between. I'll ring a few places tomorrow. Ta. Link to comment Share on other sites More sharing options...
Archie Procter Posted April 12, 2011 Share Posted April 12, 2011 or email me (address in profile) for details of someone who has the software and expertise to read these things in detail. I have some sympathy, I chased things round for ages before getting to the root of my issues. Link to comment Share on other sites More sharing options...
Loverobot Posted April 13, 2011 Author Share Posted April 13, 2011 LOL Coyoteracer! Small problem of me having not driven the car having been in plaster and then a cast brace for months prevented me acting on advice immediately esp as I can only now hold and use a screwdriver! At the time I did check the cable and the pivot bolt but they were fine - I have now reckecked them and they are fine. I also wiggled and unplugged but no result The advice that I followed involved me looking into the IACV amongst other things but I had no idea which 'bit' the IACV is hence the bit I hadnt done I now know where it is and was simply asking re the things to watch out for before I sprung a spring across the garage and hunted for it for hours Edited by - Loverobot on 13 Apr 2011 06:09:06 Link to comment Share on other sites More sharing options...
CharlesElliott Posted April 13, 2011 Share Posted April 13, 2011 Because things are fairly simple in MEMS, and OBD2 gives you most of what you need and any/every garage would have one of those. Testbook is the Rover special diagnostic kit, and would be more difficult to track down - any ex-Rover or XPart dealer is likely to have one though. The non-tech answer is to unplug each sensor in turn and see whether the engine note changes 😬 Link to comment Share on other sites More sharing options...
Loverobot Posted April 13, 2011 Author Share Posted April 13, 2011 Okay - will get unplugging! On a + note I am going to the GTKY7 midlands meet and will have the car with me - I guess they will have the plug in unit if all else fails?! Link to comment Share on other sites More sharing options...
grumpy the 7th Posted April 13, 2011 Share Posted April 13, 2011 Quoting coyoteracer11: TB is irrelevant, Over tightened air filter on a plastic TB had a very definite effect on my car, the TB plastic became so eliptical the butterfly wouldn't close fully which caused a tickover of over 2k rpm. Most embarrasing at junctions and traffic lights 😳 I'd already gone through a few other tests prior to diagnosing the TB AND gone through the IACV spring search 🙆🏻 with a speaker magnet swept over the garage floor similar to a mine sweeper 😬 rog Link to comment Share on other sites More sharing options...
TomB Posted April 13, 2011 Share Posted April 13, 2011 Mine recently had this issue - in fact it had it last year and Ive only just got round to looking at it. It was idling at 1800 hot (at traffice lights for example). I simply cleaned the IACV connections with brake cleaner on a cotton bud (filthy); removed the IACV and checked it was clean; slightly greased the piston; and reset the throttle body by 7 application of the thottle. It seems much better now - hopefully thats cured it. If mucky oily contacts are preventing the ECU talking to the IACV and controlling the small piston actuating the thottle, I think it would explain the high idle. Link to comment Share on other sites More sharing options...
Leadership Team SLR No.77 Posted April 13, 2011 Leadership Team Share Posted April 13, 2011 It's very unlikely to be the IACV. The IACV functions at low revs to allow tickover - at higher revs it is completely closed. An engine stalling rather than ticking over is more symptomatic of IACV failure. Go back through the thread - SM25T mentioned something sticking - it could be absolutely anything between your foot and the TB butterfly valve - throttle pedal, throttle cable, TB housing (as Roger mentions) or even simply the butterfly shaft needs lubrication. Most likely is the air filter being over tightened on the plastic TB housing - it's been the culprit many many times over. Stu. Link to comment Share on other sites More sharing options...
oilyhands Posted April 13, 2011 Share Posted April 13, 2011 With respect Stu, that's not right, the IACV 'soft lands' the engine when backing off the throttle to reduce emissions. A good way of finding out if it is the IACV is to unplug it when the engine is idling, then see if the engine 'soars' when driving, if it doesnt then that is your culprit, if it does, look elsewhere. Oily Link to comment Share on other sites More sharing options...
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