MZpog 10 Posted February 10, 2015 Found this http://www.classic-audi.co.uk/forum/showthread.php?t=29491 which relates an Audi, but still relevant. Shame the Corrado MAF doesn't unbolt like this one. Quote Share this post Link to post Share on other sites
Peacedub 10 Posted February 10, 2015 (edited) Found this http://www.classic-audi.co.uk/forum/showthread.php?t=29491 which relates an Audi, but still relevant. Shame the Corrado MAF doesn't unbolt like this one. Good thread and very similar to corrado. Maybe you can strip down the MAF potentiometer but i dont think i would like to try it! i think you would have to strip the whole metering head to get to the inside like what the picture shows but again i wouldnt like to try. That graph is the one thats in the bentley but i believe its slighty different but in very very slighty. where 4.8vdc shows 0.8vdc ish outout and i was getting 1.0vdc output which is way off the scale. i will get a pic tonight of what i did as those pics on audi are not very clear. I plan to do the injector test on mine, i think the difference in his complete test is that is was done on a 5 pot motor Just read replies further down. The ones that you can gain access to (MAF) are ones without an idle screw so adjustment is made within the unit i believe. Does not applies to us Edited February 10, 2015 by Peacedub Quote Share this post Link to post Share on other sites
Peacedub 10 Posted February 10, 2015 Cheers fella, hopefully it will be dry at the weekend so I have a go at it. Did your pre destruction tweaking sort out the idle issue? Yes indeed! it ran like a dream!! it still wasnt right and not in spec but felt a million times better than before hence why i tried tweaking a bit more. Just imagine what it would have been like if i would have got it in spec?? Hopefully my new unit will come today or tomorrow. I will do the same test on new unit and catalogue pics of how i did it Quote Share this post Link to post Share on other sites
MZpog 10 Posted February 11, 2015 Yes indeed! it ran like a dream!! it still wasnt right and not in spec but felt a million times better than before hence why i tried tweaking a bit more. Just imagine what it would have been like if i would have got it in spec?? Hopefully my new unit will come today or tomorrow. I will do the same test on new unit and catalogue pics of how i did it Look forward to seeing them. Quote Share this post Link to post Share on other sites
Peacedub 10 Posted February 11, 2015 (edited) Ok guys here it is. My new metering head hasn't arrived yet but my ABS sensor did so after I fitted that I created this catalogue. And just to add what a byatch the sensor was to do! Metering head (to the left the white plug for MAF) http://i1052.photobucket.com/albums/s441/sparkypeace/corrado%20maf/45fa74c3f25d78429d32fb03d852ac81_zpsc2feae3b.jpg[/img]"]http:// The MAF plug disconnected http://i1052.photobucket.com/albums/s441/sparkypeace/corrado%20maf/b0d0fbcee95520376abdca52e779897b_zps7e45db15.jpg[/img]"]http:// Ignition on input reading pins 1 & 3 (I said 1&2 before my bad) http://i1052.photobucket.com/albums/s441/sparkypeace/corrado%20maf/7cee0bea800576b909244d5f550e43fd_zpsc695cfbd.jpg[/img]"]http:// MAF potentiometer (the hole to the left is where the trim screw should be, notice mine hasn't got 1! This should be covered in silicone originally and once trimmed be siliconed back up) http://i1052.photobucket.com/albums/s441/sparkypeace/corrado%20maf/8a35c2923a4c828562041aec81f595b5_zps1666a40e.jpg[/img]"]http:// Connected back in MAF. Protective boot pulled back and take readings from pins 2&3 while engine running and at idle for 2 mins http://i1052.photobucket.com/albums/s441/sparkypeace/corrado%20maf/3993fb3edb312fe44236dfd16d85039c_zps48b2876b.jpg[/img]"]http:// I was getting no reading meaning its duff but I was getting 1VDC before http://i1052.photobucket.com/albums/s441/sparkypeace/corrado%20maf/0af1f87cf2d332ff7ca434476d32f037_zpsaf01c55d.jpg[/img]"]http:// The graph in Bentley. 4.8vdc input should get between 0.48vdc and 0.82vdc so mine before destruction was way out http://i1052.photobucket.com/albums/s441/sparkypeace/corrado%20maf/a0a67617a777d57a2918fac7eeb76fa1_zps99727b55.jpg[/img]"]http:// Bentley guide http://i1052.photobucket.com/albums/s441/sparkypeace/corrado%20maf/3b79f37e3d688e36cfabaf2cc0adedbc_zps34482e46.jpg[/img]"]http:// I hope this gives you guys a good guide to testing your valver if it's running a bit rough. It takes literally 2 mins to do and is well worth doing if you think it might be something else like I did, i.e ISV or idle switch Edited February 12, 2015 by Peacedub Quote Share this post Link to post Share on other sites
MZpog 10 Posted February 12, 2015 With pictures too, this should be a sticky. As you've busted your MAF, are you going to attempt removing it from the metering head to have a look inside? I wonder if there are any screws hiding under what looks to be silicone to the sides. Quote Share this post Link to post Share on other sites
Hairyarse 10 Posted February 12, 2015 One for the Wiki I guess :thumbleft: Quote Share this post Link to post Share on other sites
Peacedub 10 Posted February 12, 2015 With pictures too, this should be a sticky. As you've busted your MAF, are you going to attempt removing it from the metering head to have a look inside? I wonder if there are any screws hiding under what looks to be silicone to the sides. Dont think i will try remove any part of it. To me the whole metering head looks like a delicate bit of kit so will just keep hold of it for spares, i.e dp regulator and airbox. Once off though i will give it a good once over and see if it is possible to remove from the outside but i definitley dont want to be messing about inside the unit. Hopefully new unit will be here tonight so will do the same check on that and update with pics of readings (thats if its all good and in spec,lol) Quote Share this post Link to post Share on other sites
davidwort 0 Posted February 12, 2015 really useful info :thumbleft: especially as the KE-jet (CIS-E) is a mystery to most garages, let alone owners! Quote Share this post Link to post Share on other sites
Peacedub 10 Posted February 13, 2015 Hi all, Just an update. Received new metering head today and fitted. Checked output of MAF and reading within spec 0.7Vdc. I believe now I need a new lambda because it still brought up fault code 516 (Tps) & 525 (02 sensor). The 525 cleared but then comes back. Also depending on ignition timing depends on when it back pops on down revs between 2-1k rpm. If it's at idle at 950rpm it back pops a lot and sounds like I have a race cam in but if I adjust the ignition timing so idle above 1000rpm it's really smooth BUT keeping it there I lose power just like when you advance and retard a cam, same theory really with the ignition timing. I get good top end when it's at low idle rpm but really bad power low down and vice versa when timing adjusted to idle over 1000 rpm. Hope all that makes sense? Going to borrow mates C02 probe and see what's going on. On a good note the new head has really made a difference with the idle, it's steady as a anything without a murmer. Do I need to leave the timing and let it adjust on its own? I know it's not good if you keep adjusting it. I just want it back the way it was when it was wanting to wheel spin everytime it hit 3.5 - 4k rpm and kept going to redline! Quote Share this post Link to post Share on other sites
Hairyarse 10 Posted February 14, 2015 Sounds like you're making good progress then. Maybe it's worth just biting the bullet and replacing the lambda for peace of mind, then stick the timing back. Quote Share this post Link to post Share on other sites
Peacedub 10 Posted February 14, 2015 Sounds like you're making good progress then. Maybe it's worth just biting the bullet and replacing the lambda for peace of mind, then stick the timing back. Yup i hear ya. Just bought this off Ebay this morning which i thought what damn good price! http://www.ebay.co.uk/itm/151257951807?_trksid=p2060778.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT Had a fun drive in to work this morning. Started up lovely, got it up to temp and it struggled to reach 4k rpm backfiring all over but as soon as it did hit 4k it nearly broke my neck and was up to redline in no time so top end was good! so i limped and bunny hopped down the drive into work (a little embarrassing).left to idle and it just died. Fired it straight back up and sweet as a nut. Must be Lambda sensor, plus my mpg was extra shocking. Timing, mpg, backfire... its got to be lambda? i did remember though not seeing an earth coming from the connector on the engine mount. The investigation continues!! Quote Share this post Link to post Share on other sites
seanl82 23 Posted February 14, 2015 Give your maf a clean with electrical contact cleaner too. I had exact same symptoms on my mk3 Golf but at 3k rpm and this was the cause. The contact cleaner fixed the problem. :thumbleft: Quote Share this post Link to post Share on other sites
Hairyarse 10 Posted February 14, 2015 That does look a good price, and with a connector too, not bare wires to splice in. Quote Share this post Link to post Share on other sites
Peacedub 10 Posted February 14, 2015 (edited) Well that was an eventful afternoon! The car decided to do its bunny hopping trick all the way home and took nearly an hour to do 7 mile! Got the mighty bible out again to try and figure out what the hell was going on. Apparently when your car goes into limp mode...if that's what you call it more like crippled mode, it's the differential pressure module telling the ECU it has a fault SO i shall start on that. I disconnected the connector while at idle. Revs pick up and sits nicely with no backfiring so i do my tests on dp module and guess what? The new metering head I got has a duff dp module :bonk:. So I swapped with my old one and now it's running really good, better than it's ever been but still got fault code 516 and occasionally 525. New VAG lambda on its way, if this doesn't cure it then I'm going to break it. As I go through the car fixing faults I can see on everything I rectify that some muppet has had his hands there. Some of the quick fix bodges is beyond belief and these people should be shot for their crimes to classic vdubs. Edited February 14, 2015 by Peacedub Quote Share this post Link to post Share on other sites
Peacedub 10 Posted February 14, 2015 Give your maf a clean with electrical contact cleaner too. I had exact same symptoms on my mk3 Golf but at 3k rpm and this was the cause. The contact cleaner fixed the problem. :thumbleft: If it's an ABF you had then it's completely different MAF. 9a's have a sealed unit that you can't get into only allowing you to adjust. The readings taken from my new unit are bang on so I know it's doing its job correctly. Thanks for the info anyway :thumbleft: Quote Share this post Link to post Share on other sites
seanl82 23 Posted February 14, 2015 Ah fair enough, no worries! Quote Share this post Link to post Share on other sites
MZpog 10 Posted February 16, 2015 Had a go at my MAF over the weekend. Voltage was 4.8 at the plug and 2-3 was a little out of spec on the low side. Whilst under the bonnet I lent on the elbow that comes off the metering head and it stopped the surging. Tried this a few times and ever time stopped the surging. Plan b, into garage for the spare I have, fitted this and now idle is sorted. Weird thing was I can't see any splits in the elbow and spraying round it with easy start didn't affect. Sorted now (I hope) Quote Share this post Link to post Share on other sites
Peacedub 10 Posted February 16, 2015 Had a go at my MAF over the weekend. Voltage was 4.8 at the plug and 2-3 was a little out of spec on the low side. Whilst under the bonnet I lent on the elbow that comes off the metering head and it stopped the surging. Tried this a few times and ever time stopped the surging. Plan b, into garage for the spare I have, fitted this and now idle is sorted. Weird thing was I can't see any splits in the elbow and spraying round it with easy start didn't affect. Sorted now (I hope) Well I wish I had that kinda luck! Have you read my update and dramas that happened on Saturday? I've had a serious amount of bad luck with this car but I WILL NOT BE DEFEATED! The dp regulator must have gone that morning as it was all good day before. If your MAF was out of spec on the low side i personally would adjust using the trim. Mine was high so I needed to unscrew in which I think I pooped the screw off as I went too far. If you are low then you will be tightening so no chance of that happening oh and you were right about the screws hidden on each side under rock hard silicone. Must be covered good for a reason! On the other hand if your car is running good then I would leave it,lol. These cars have a tendency to self destruct by just looking at them. Quote Share this post Link to post Share on other sites
Peacedub 10 Posted February 19, 2015 Hey guys just another update. The big C has been running like a dream since Saturdays palava (replaced MAF then dp sensor) and I am back loving it! I'd ordered an original vw lambda probe which came today so I fitted tonight. While replacing I had to take the cat off as the probe was stuck on solid. For those that have replaced these probes there is not much choice of tool to actually get in the tight space so off came the cat. While removing I unveiled yet more horrors from the previous owners who I think worked at halfords only on a Saturday! Instead of exhaust putty on the joins and donut it was silicone yes SILICONE! So off went the cat and on the vice. Probe was an original VAG unit so that was good. Replaced with new and refitted the proper way. To be fair I can't really tell a difference so I wonder if I had cured it on Saturday. At least i know the sensor is new and will last its time. Still getting the fault code 0516 (TPS potentiometer) though. It's running beautiful now so I'm just going to ignore it for the time being and enjoy my car! Hope thus thread helps you guys out there diagnose your faults, albeit you don't go to the lengths I did and it turns into an easy fix. Thanks for all your help and comments Quote Share this post Link to post Share on other sites
MZpog 10 Posted February 19, 2015 Silicone is a good exhaust sealant, but with the correct gaskets etc. Glad you're enjoying the C. I too have had fabulous idling and great (ish) mpg for the last few days, its a joy when they behave. Quote Share this post Link to post Share on other sites
Peacedub 10 Posted February 19, 2015 Silicone is a good exhaust sealant, but with the correct gaskets etc. Glad you're enjoying the C. I too have had fabulous idling and great (ish) mpg for the last few days, its a joy when they behave. I have to disagree with the silicone on the exhaust. It is never meant to see that kind of heat especially on the down pipe that connects to cat. The remains of the silicone had disintegrated when touched so it was deemed useless. It is a joy at the minute and all the hard work has paid off. I've practically rebuilt the car since October so I know its on the right track to be a little cracker. I stripped the whole interior at the weekend and replaced all door clips and anything that was rattling. I rebuilt the dash and all under trays so it is proper solid now. MOT in few week so fingers crossed! Quote Share this post Link to post Share on other sites
Hairyarse 10 Posted February 20, 2015 Great news, at least all of your hard work and patience has paid off! :) Quote Share this post Link to post Share on other sites
nmahi 0 Posted May 29, 2015 hows the corrado, still running well? and further issues? still playing with mine :( Quote Share this post Link to post Share on other sites
