scarlet_vr6 0 Posted April 22, 2007 well whilst fitting my BMC at the weekend and (due to a slight oversight :oops:) I disconnected the MAF with the keys in the ignition. The car now runs really badly - hesitating, lumpy and have to rev loads under load. It's pretty much ok once the revs are up and I think any probs here are due to needing a new coilpack. I'm 99% sure that the keys weren't turned at all when I disconnected the MAF, just in the ignition barrel. Do I need to reset the engine ECU to sort this out? I've looked at the wiki but have a few qs now... do I def need VAG-COM? yes, I've read the sentence in bold (!) but the first paragraph implies that the basic setting is only needed if the battery is disconnected. If I disconnect just the engine ecu, can I get away without needing VAG-COM? I guess not but I'm hoping... If I do need it, do I need the full version? I've been looking at Ross Tech's website and wondered if I could get away with just the shareware version? Finally, if I do need the full version, does anyone have it in the Hampshire/Berkshire area and fancy helping me out :wink: Any help much appreciated! Quote Share this post Link to post Share on other sites
Goldie 2 Posted April 23, 2007 Heres the info i read about the BMC Fay... http://www.bmcairfilters.com/infoCDA.asp Quote Share this post Link to post Share on other sites
dr_mat 0 Posted April 23, 2007 If you disconnect the ECU's power, that's just the same as disconnecting the battery - the ECU loses it's settings. It should readjust automatically though. Most likely your ECU has marked the MAF as dead and is now refusing to reenable it. Even with the basic VAG-COM you should be able to delete the error code for that and it will then come up ok (or it should). Quote Share this post Link to post Share on other sites
Tekara 0 Posted April 23, 2007 If needed ive got Vagcom, im near Andover so not too far away. Quote Share this post Link to post Share on other sites
scarlet_vr6 0 Posted April 23, 2007 thanks for info guys. dr_mat, your comment about it readjusting automatically is very interesting. I got stuck in traffic this morning at the end of a 45 min drive and had to wait a further 45 mins in a queue. After that, it was running fine, well back to the coilpack misfire :roll:, but this evening it was back to needing loads of revs and hesitating for the first 20 mins or so. Does this mean the ECU is now forgetting everything as soon as I take the keys out of the ignition until I get the fault code deleted? Is this possible or is there a new problem to worry about?! Tekara, depending on replies to the above, I may just pop into Storm Devs one lunchtime (I work next door) and see if they will delete this code. Offer is very much appreciated though and I might be over yet! Thanks again. Quote Share this post Link to post Share on other sites
dr_mat 0 Posted April 24, 2007 I would say: get it scanned, get the error codes checked and deleted, check the readings of the temperature sensors... If it's only rough while it's cold it's probably not doing cold start enrichment properly.. BTW, take a look at the basic settings procedures. When you reset the ECU it goes into "quick learn" mode, which is why you're supposed to immediately get out there on the open road and teach it about the air flow characteristics of your engine (hoping at this point that your lambda is working well).. Quote Share this post Link to post Share on other sites
scarlet_vr6 0 Posted April 25, 2007 I went to Stealth at lunchtime today and there are no faults stored on VAG-COM. I did manage to pick up a used coilpack for £20 though with 60 day warranty. Just need to fit it (hopefully tomorrow night) and see what difference, if any, that makes... Quote Share this post Link to post Share on other sites
Goldie 2 Posted April 25, 2007 I went to Stealth at lunchtime today Did you, i thought it was Storm.... :wink: Quote Share this post Link to post Share on other sites
scarlet_vr6 0 Posted April 25, 2007 I went to Stealth at lunchtime today Did you, i thought it was Storm.... :wink: yep you're right! It was Storm... I'll use the time of my post as my excuse! Quote Share this post Link to post Share on other sites
Roger Blassberg 0 Posted April 25, 2007 As I understand it, disconnecting the MAF does not mean that you need to do a basic settings, only if you isolate the ECU from the battery as The Good Doctor has said. And I have been told that the $99 deal with Ross Tech includes basic settings. Could it be that the MAF connections are somehow intermittent since you fiddled about with it? Maybe a good clean of the pins and the connector socket are your solution. Best wishes RB Quote Share this post Link to post Share on other sites
scarlet_vr6 0 Posted April 25, 2007 replaced the coilpack tonight with my bargain replacement and life is oh-so-sweet! Only have the slightest of hesitation now when pulling away so I've bought some injector cleaner and we'll see what happens. Feeling ridiculously pleased with myself for changing the coilpack on my own. It took me about 15 mins. Bit pathetic really cos I know it's not exactly a difficult job but aside from usual water/oil checks, it's the first work I've done by myself. So I went out for a short drive. My reward? Seeing 2 other Cs and getting a wave from each! :cheers: Quote Share this post Link to post Share on other sites
Goldie 2 Posted April 25, 2007 Good stuff Fay.. Today its coilpack swaps, in the future itll be R32 conversions.... (on my car) Quote Share this post Link to post Share on other sites
RS VR6 0 Posted April 26, 2007 What I did to clear my ECU was to: 1. Disconnect the battery 2. Touch the termials at the end of the cables together for ten seconds. This will completely discharge the capacitors. Quote Share this post Link to post Share on other sites
