Robbo149 0 Posted June 21, 2004 Hi all, been doing a bit of tinkering at the weekend (ooeer!), & thought I'd give my MAF a quick check to try & suss out some flat spot isses (I haven't been able to get it checked on VAG-COM yet). Anyway, I ran the car up to normal op temp & unplugged the MAF... nothing happened, no change in idle or anything. So I went for a quick drive around the block & the car drove exactly the same as before. Oh bugger! I thought, dead MAF. Except I then switched off the ignition & re-started & it ran like a bag of spanners, wouldn't idle etc. as you'd expect with the MAF unplugged. Is this normal? Cheers, Robbo Quote Share this post Link to post Share on other sites
Dilated 0 Posted June 21, 2004 My car has been running fine, but this morning on my way to work it suddenly starting running lumpy and a bit 'juddery'. I've been reading up on this on the forum and thought i'd try unplugging the MAF sensor just now (lunchtime). First off better check, is the MAF sensor the one to the top left of the airbox on the intake pipe? (Never had a car with all these electronic gubbins everywhere!) Well if it is, I unplugged it and nothing happenned, when i plug it back in I get an ever-so-slight flutter in rpm and back to normal. I say normal, I mean back to normal lumpyness. Does this mean it's knackered? I thought the engine was supposed to die when unplugging the MAF? Quote Share this post Link to post Share on other sites
PhatVR6 0 Posted June 21, 2004 you should never unplug anything with the ignition on.. Quote Share this post Link to post Share on other sites
dr_mat 0 Posted June 21, 2004 Dilated, that seems to be how the late model VR engines all handle a MAF-unplugged situation. Unless we've all got knackered MAFs I wouldn't worry about it.. Quote Share this post Link to post Share on other sites
Dilated 0 Posted June 21, 2004 I don't mean to hijack Robbo's thread, but would a duff MAF cause this lumpy/rough running then? I have recently fitted new ht leads (about a month ago) and plugs (a couple of months ago now) however, the old plugs 1 and 6 were rather oiled up. I'll check these tonight, perhaps they could be so oiled up again that they are preventing a decent spark? When my HT leads were knackered (or one of them) it just burbled now and again but didn't run anywhere near as bad as it is doing now. Quote Share this post Link to post Share on other sites
dr_mat 0 Posted June 21, 2004 (OT yes that's true. If you've got oiled spark plugs it's most likely either the head valve stem seals etc or it's the cylinder bores causing it. Either way it's easily going to cause fairly major rough running...) Quote Share this post Link to post Share on other sites
Dilated 0 Posted June 21, 2004 I just find it a bit odd that all of a sudden it starts to run really rough. If it was getting oiled up again, surely it would start missing a little bit, then get worse. Car has been running perfectly till part way through my journey this morning! :( Quote Share this post Link to post Share on other sites
dr_mat 0 Posted June 21, 2004 Well to be honest, there's little or no point chasing failed MAFs if you are having plug fouling issues. Depending on how long it takes to foul the plugs, it's time to sell up or get it fixed! How much oil is being used? (And what type is it?) Quote Share this post Link to post Share on other sites
Kevin Bacon 5 Posted June 21, 2004 Mine idles badly intermittantly with a new head, so I wouldn't worry about any mechanical elements of the engine just yet. I dropped a new Cam sensor in over the weekend and reset the ECU and it was a ballistic missile on the way to work this morning. Dead smooth idle too. There is some kind of extreme fussiness with the VR's sensors/ECU that causes a rough idle. Only way to be sure on the MAFs I've found is to buy a new one and see if it improves matters. I did in my case, but if it doesn't, having a new one won't hurt anyway. As for unplugging things with the ignition on, doesn't make any odds with the ECU related components as it has physical protection against voltage surges, short circuits and open circuits. K Quote Share this post Link to post Share on other sites
Dilated 0 Posted June 21, 2004 dr_mat - been over the oil issue in the past, now running Mobil1 15/50 and it seems to have slowed down the oil burning rate. I find it still burns oil on motorway runs, mostly over around 3.5krpm but I can cope with this for now (until I have some cash to sort it out properly) cheers for the suggestions kev, not sure that it 'wouldn't hurt' to have a new MAF sensor on there, i'm pretty sure it would hurt my wallet at the moment, especially with the prices I read about in a different thread! My brother has a VR too, so I might just drop by his place tonight and switch them over. Is it an easy job? Will I need to rest the ECU after swapping them over? If this makes no difference would it be wise to try spraying fine water mist over the coilpack trick tonight? Are these symptoms consistent with a dodgy coilpack too? hmmm, questions questions question... Quote Share this post Link to post Share on other sites
Dilated 0 Posted June 21, 2004 Sorted it, took plug number 1 out - oiled up nicely. Gave it a clean up and put it back in. Runs nice again... Sorry for the wasted time on this thread, it's just that it happened on the way to work and after searching the forum the symptoms pointed to MAF sensor! The plugs were oiled up a lot worse a couple of months ago and it still ran okay. Temperamental beast that it is... Thanks for your help anyway, hopefully now someone can help out Robbo149! Sorry bud. Quote Share this post Link to post Share on other sites
Robbo149 0 Posted June 22, 2004 Had it on Bosch diagnostic machine last night at mate's garage (great when you can get it done for free!) - 'Hall Sensor error' - same as I had before when cam position sensor was caput! I replaced it about 6 months ago, so I guess either it's got damaged while the head was being replaced, or it's not connected properly. Cheers, Robbo Quote Share this post Link to post Share on other sites
