Peacedub 10 Posted February 1, 2015 Hi all, I know this has been discussed on numerous occasions but i just cant seem to put my finger on the issues im having. To be fair its bareable but my fuel consumption is terrible. When i start from cold its bang on but then when it gets up to temp it starts to fluctuate and if i come to a stop it stalls but then when i restart it sits beautifully at 950rpm without a murmer. But sometimes it sits at 1500rpm all the time. I just find it strange that its different everytime you restart. These are the fault codes im getting 516 (TPS) - 99% on all the time. Once it cleared and didnt come back on but that was just once! 525 (o2 sensor) - Random. On off and clears everytime 587 (mixture control) Only came on this morning while driving then cleared straight away. I originally thought the roughness was due to KR cam swap but the timing is bang on. I found myself constantly adjusting ignition timing but this would mess everything up up each time i drove, then idle then switch off then start, the idle was different each time one of these happened plus depending on advance or retard obviously messed with the running (good or bad/bottom or top end) The throttle microswitch clicks in and out. Im not sure if i have a tps switch or potentiometer. Could it be running rich all the time? hence explaining the **** fuel consumption (avg 20mpg). I have no vac leaks or injector leaks as i have checked these. Next thing really is to do a resistance check on tps plug. Just wanted to know if any of you have experienced anything similar? (late spec 92 2.0 16v 9a) Thanks in advance Steve Quote Share this post Link to post Share on other sites
Hairyarse 10 Posted February 1, 2015 Possibly lambda probe, mine wasn't connected properly - however symptoms weren't quite the same. If you've not seen this before it could help you cover some of the basics and anything you've potentially missed, as it's easy to overlook a few things - http://www.vwgolfmk2.co.uk/forum/viewtopic.php?f=37&t=25972 I know he guide is for the KR but it's very similar to the 9a so should be useful Quote Share this post Link to post Share on other sites
Peacedub 10 Posted February 1, 2015 Possibly lambda probe, mine wasn't connected properly - however symptoms weren't quite the same. If you've not seen this before it could help you cover some of the basics and anything you've potentially missed, as it's easy to overlook a few things - http://www.vwgolfmk2.co.uk/forum/viewtopic.php?f=37&t=25972 I know he guide is for the KR but it's very similar to the 9a so should be useful Thanks for that, i have read it some stage but just scanned through it as i wasnt having an issue at the time. Will print off and wait for a warm day to go through it. John is the font of all knowledge. His digi setup guide was awesome for my mk2! Just to add i disconnected the probe connector on top of engine mount and it did nothing so probably worth while getting a new probe.. Quote Share this post Link to post Share on other sites
easypops 8 Posted February 1, 2015 I chased a poor running/bad idle for ages on my old valver (9a) and found the cause by fluke, 2 of the 3 wires were split for the throttle potentiometer (TPS) which is attached to the throttle body, my issue was that the plastic sheathing was still ok so it looked fine. Once I repaired the wires it ran great......made me wish I hadn't replaced the ISV,fuel pump,metering head,leads,plugs etc etc :lol: Quote Share this post Link to post Share on other sites
Peacedub 10 Posted February 1, 2015 I chased a poor running/bad idle for ages on my old valver (9a) and found the cause by fluke, 2 of the 3 wires were split for the throttle potentiometer (TPS) which is attached to the throttle body, my issue was that the plastic sheathing was still ok so it looked fine. Once I repaired the wires it ran great......made me wish I hadn't replaced the ISV,fuel pump,metering head,leads,plugs etc etc :lol: Yes exactly why i need to nip it in the bud now before it costs me the earth (as usual with dubs) and the mrs starts kicking off cos there is a million parcels being delivered. You know we have all been there!! will crack the multimeter out and start doing some fault finding. First i need to check if its a switch or a potentiometer, i cant remember? will check the pins 1,2 &3 resistance figures while at idle and revs. Quote Share this post Link to post Share on other sites
easypops 8 Posted February 1, 2015 It was listed as a potentiometer when I bought it.....sadly I couldn't tell you the difference between that and a switch:) Quote Share this post Link to post Share on other sites
Hairyarse 10 Posted February 2, 2015 Thanks for that, i have read it some stage but just scanned through it as i wasnt having an issue at the time. Will print off and wait for a warm day to go through it. John is the font of all knowledge. His digi setup guide was awesome for my mk2! Just to add i disconnected the probe connector on top of engine mount and it did nothing so probably worth while getting a new probe.. Yeah John's knowledge is amazing!! If you do the lambda, double check how many pins the plug is. When I bought mine (returned it as found the broken wire) it was 2 wire and mine was three (or it could have been 3 and 4 lol) I'm guessing as with some other parts for the 9a, there's a cross-over point where certain parts are different so have your engine number to hand when you order. Quote Share this post Link to post Share on other sites
MZpog 10 Posted February 2, 2015 Just sitting on the fence, waiting for the responses as my valver has also had an upset idle after a KR cam change. Cold idles fine about 900 rpm, warm sometimes fluctuates revs from 1000 to 1100. MPG has taken a battering too and it smells rich (will get it RR setup at some point). Quote Share this post Link to post Share on other sites
Peacedub 10 Posted February 2, 2015 Just sitting on the fence, waiting for the responses as my valver has also had an upset idle after a KR cam change. Cold idles fine about 900 rpm, warm sometimes fluctuates revs from 1000 to 1100. MPG has taken a battering too and it smells rich (will get it RR setup at some point). Yup exactly what mine is doing. Please let me know how the RR goes. Hopefully this weekend i shall start some fault finding with the fluke, not had chance yet due to no daylight! its annoying as it was ok prior to cam swap, was a bit sluggish to start but then further up the revs it was sweet. Timing is absolutley bang on since swap. up the revs its lovely and can tell the cam is working its just the idle and setting of is very hesitant. Also stinks of fuel. Im thinking the fault code 516 (tps) is thinking its at WOT and overfuelling?? Quote Share this post Link to post Share on other sites
MZpog 10 Posted February 2, 2015 RR session will have to wait until I've fitted the 50mm inlet. Quote Share this post Link to post Share on other sites
MZpog 10 Posted February 4, 2015 Just checking for any update on this as mine was fluctuating like a good en on the way in to work today. Also forgot to mention, another symptom is when getting off the gas its a jerky on/off feeling. Once revving its a peach. Quote Share this post Link to post Share on other sites
Peacedub 10 Posted February 4, 2015 Just checking for any update on this as mine was fluctuating like a good en on the way in to work today. Also forgot to mention, another symptom is when getting off the gas its a jerky on/off feeling. Once revving its a peach. You have the same symptoms as mine. cruising along at 2-3k its really juddery but loves it when you cane it! Still not got around to fault finding but hopefully doing it this weekend so i shall have to grin and bear it till then. I have noticed since i cleared the 00525 (lambda probe)fault numerous times that the revs dont really go below 800rpm and subsequently stall everytime i pull up at some lights so thats a glimmer of hope. I really am thinking its my throttle position sensor playing up and not knowing where the hell it is! Quote Share this post Link to post Share on other sites
easypops 8 Posted February 4, 2015 It's on the throttle body Quote Share this post Link to post Share on other sites
Peacedub 10 Posted February 4, 2015 It's on the throttle body Sorry it was worded wrong I meant the TPS doesn't know where it is meaning is it thinking its WOT or idle cos it stinks of fuel and getting crap mpg. Still not checked if it's a switch or potentiometer I'm guessing the latter because my mk2 golf has a switch and the corrado is later spec. We shall see Quote Share this post Link to post Share on other sites
davidwort 0 Posted February 4, 2015 how old is the lambda sensor, I'd suspect that given that you say it's OK on cold start and then there's idle probs etc. trace the lambda wiring too check there's no damaged wires and if you replace it get a decent quality one NTK etc not just the cheapest generic sensor you can find as these seem to give lots of trouble too. fiddling with the ignition timing will just make matters worse as the ecu is struggling to compensate and KE jet is pretty limited anyway as there's no pre cat sensor. ISV's cause trouble too but usually limited to idling too high or too low, sticking as the unit gets weak with age as well as gummed up. If you can it would be good to check the other temp sensors are providing a nice curve of resistance against temp and within spec but I'm betting on the lambda Quote Share this post Link to post Share on other sites
Peacedub 10 Posted February 5, 2015 how old is the lambda sensor, I'd suspect that given that you say it's OK on cold start and then there's idle probs etc. trace the lambda wiring too check there's no damaged wires and if you replace it get a decent quality one NTK etc not just the cheapest generic sensor you can find as these seem to give lots of trouble too. fiddling with the ignition timing will just make matters worse as the ecu is struggling to compensate and KE jet is pretty limited anyway as there's no pre cat sensor. ISV's cause trouble too but usually limited to idling too high or too low, sticking as the unit gets weak with age as well as gummed up. If you can it would be good to check the other temp sensors are providing a nice curve of resistance against temp and within spec but I'm betting on the lambda Some good advice there. Where would i find the specs to plot the resistance checks? i have the bentley book for mk2 golf which also covers KR but ive not managed to have a look yet, its going to be a busy weekend for me,lol. I have planty of ISV's knocking about so will give that a shot too Quote Share this post Link to post Share on other sites
MZpog 10 Posted February 5, 2015 Dunno about you Peacedub, but mine only started after the KR cams were installed which initially led me to believe I had an inlet leak as the intake was the only think disturbed. Last night when doing it's revving up/down I nipped the pipe from the ISV to intake and by restricting it's flow the idle settled. I also tried unplugging the cold start injector to see if it was to do with this, no change. Then unplugged the ISV and no change. If I get some time this weekend then I'll do some more checks, starting with the throttle switch as this could have been disturbed during the cam change. Whatever it is, it's intermittent as this morning worked fine with steady idle (albeit high) and a nice 31MPG registered. Quote Share this post Link to post Share on other sites
Peacedub 10 Posted February 7, 2015 Ok so here's an update, and an annoying one at that! It looks like I (now) need a new metering head! Explanation below. I had my head in the Bentley book for a good 3 hours last night and today I went to town with some testing. Tps idle closed - test all good = 1 ohm Tps idle open - test all good = o/c Tps full throttle closed - test all good = o/c Tps full throttle open - test all good = 1 ohm Sensor plate checked correct alignment with no fouling, easy to lift with magnet Temp sensor - all good. Reading 7-800 ohms at 55 degrees temp when tested ISV all good - 12v on connector 9 ohms on sensor Differential pressure regulator - all good reading 19.8 ohms. Max 20 as specified A couple of others I did but all passed tests........ Now here comes the not so funny part. I came to check the air flow sensor potentiometer located to the left of metering head. Here is what this does for the car as described in Bentley "The air flow sensor potentiometer provides the engine load signal to the ECU for control of ignition timing, acceleration and full throttle enrichment" I decided to leave this till last as all these 3 sounded like symptoms I have all of them so used process of elimination. I tested the lead for the correct voltage between pin 1 & 3(reading was 4.8VDC so within spec) so the next step was to connect the lead back in and connect leads to back of pins 2 & 3 while connected to sensor, start engine and idle for 2 min and take reading. So the input was 4.8VDC I should be seeing between 0.45VDC and 0.8VDC. I was get 0.98VDC so out of spec. If so you can adjust using a trim screw located next to the connection under loads of silicone. I did this while running and it started going up in volts so went the other way and got it to 0.87VDC and no further. I had a quick test of the car and it felt a 100 times better, with better throttle response and acceleration with no backfiring and good idle but I knew it wasn't in spec so I tried again but this time the screw disappeared inside the unit and now it runs like a bag of **** backfiring all over the shop and bringing up more fault codes than ever one being 0520 which is MASS AIR FLOW,lol. At least i found out what the culprit was so onto my next question..... Has anyone got a spare metering head for sale?? Quote Share this post Link to post Share on other sites
Hairyarse 10 Posted February 8, 2015 Oh poop!! At least you've found the culprit though which is a good thing. Hopefully you can find one easily enough and for not too much money ;) Quote Share this post Link to post Share on other sites
Peacedub 10 Posted February 8, 2015 Oh poop!! At least you've found the culprit though which is a good thing. Hopefully you can find one easily enough and for not too much money ;) I thought I would struggle to find one as they are unique to the 9a but I was surprised at the response I got and "Dickie" sorted me one out complete with airbox and injectors for a good price so that's great just a straight swap. I should really have left the idle screw where it was when it was running good but me being me wasn't happy that it was still out of spec and knew that it was still at fault hence why I couldn't adjust anymore and push the screw into the unit and lost it,lol. Hopefully the new unit will be here midweek so I shall update once fitted Quote Share this post Link to post Share on other sites
MZpog 10 Posted February 8, 2015 I have an old meter head in the garage and wonder if it's possible to swap the MAF from one to another, if mine too is out of spec. I had a quick look at the meter head and it appears there is a black 2 pin sensor on one side that has fixing screws and a black 3 pin sensor on the other side with no obvious screws. Quote Share this post Link to post Share on other sites
Peacedub 10 Posted February 8, 2015 (edited) I have an old meter head in the garage and wonder if it's possible to swap the MAF from one to another, if mine too is out of spec. I had a quick look at the meter head and it appears there is a black 2 pin sensor on one side that has fixing screws and a black 3 pin sensor on the other side with no obvious screws. If your having the same issues as me then I would check the MAF. It is a sealed unit so cannot be replaced unfortunately. It's the unit to the left front of metering head. The right is the differential pressure and left rear Is carbon canister. If you want to check the MAF you need to disconnect the plug and check pins 1&2 on plug itself with ignition on, it should read 4.5vdc and 5.5vdc. If you have that then thats the input all good. Then you need to plug back in and it's best to lift the airbox out so you can see the connector properly. Pull back the boot covering the back of connector to see the wires. I used 2 probes from a fluke in pins 2&3 to check the output vdc. I was getting 4.8vdc (pins 1&2 plug disconnected) input which converts using Bentley table to between 0.45vdc & 0.8vdc (pins 2&3 plug connected) and I was get close to 1.0vdc. So to the left of connector is some black silicone which needs to be removed to reveal a trim screw. Adjust according to get the right results and don't do what I did and break it!! It's properly backfiring all over and getting 99.9mpg ha ha ha. If you don't have Bentley I will take photos and post. I got close to 0.8vdc and took it for a spin. It pulled off great with no bogging down, went through the Rev range sweet with Rev gauge dropping properly. It felt really good. But I just wanted that little but more and broke it! Edited February 10, 2015 by Peacedub Quote Share this post Link to post Share on other sites
MZpog 10 Posted February 9, 2015 If you don't have Bentley I will take photos and post. I got close to 0.8vdc and took it for a spin. It pulled off great with no bogging down, went through the Rev range sweet with Rev gauge dropping properly. It felt really good. But I just wanted that little but more and broke it! I think I may have the Bentley manual on disc, however would appreciate photo's if you can. Being a bit of an electrical numpty, I am a bit confused as to what you mean by the 4.8vdc input converts to 0.45vdc & 0.8vdc on the Bentley table. Typical that the MFA would be the one that couldn't be removed to swap. Quote Share this post Link to post Share on other sites
Peacedub 10 Posted February 9, 2015 (edited) I think I may have the Bentley manual on disc, however would appreciate photo's if you can. Being a bit of an electrical numpty, I am a bit confused as to what you mean by the 4.8vdc input converts to 0.45vdc & 0.8vdc on the Bentley table. Typical that the MFA would be the one that couldn't be removed to swap. Yeah I know, but it's a really sensitive bit if kit so probably for the best That it's sealed. The input voltage is to power the sensor and is tested by disconnecting the lead and taking a Vdc reading from pin 1&2 on the lead connector and should be 4.5vdc to 5.5vdc. The output voltage is what the maf potentiometer converts as a signal output and is measured by plugging the connector back in to the maf, pulling back the rubber boot which protects the leads connections at rear, place 2 probes from fluke into pins 2&3 with ignition on and you should see a low voltage reading. From memory 4.5vdc - 5.5vdc equates to minimum 0.2vdc - 0.85vdc output if this makes sense. I was getting 4.8vdc input from connector disconnected then when plugged it back in i should have been seeing between 0.4vdc - 0.8vdc but I was seeing 1.0vdc meaning the maf was ****ed cis it would not trim anymore. I will get some pics up this week of the table and pictures of where and how. Edited February 9, 2015 by Peacedub Quote Share this post Link to post Share on other sites
MZpog 10 Posted February 10, 2015 Yeah I know, but it's a really sensitive bit if kit so probably for the best That it's sealed. The input voltage is to power the sensor and is tested by disconnecting the lead and taking a Vdc reading from pin 1&2 on the lead connector and should be 4.5vdc to 5.5vdc. The output voltage is what the maf potentiometer converts as a signal output and is measured by plugging the connector back in to the maf, pulling back the rubber boot which protects the leads connections at rear, place 2 probes from fluke into pins 2&3 with ignition on and you should see a low voltage reading. From memory 4.5vdc - 5.5vdc equates to minimum 0.2vdc - 0.85vdc output if this makes sense. I was getting 4.8vdc input from connector disconnected then when plugged it back in i should have been seeing between 0.4vdc - 0.8vdc but I was seeing 1.0vdc meaning the maf was ****ed cis it would not trim anymore. I will get some pics up this week of the table and pictures of where and how. 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? Quote Share this post Link to post Share on other sites
