1.9Tdi MAF Sensor Help
Printed From: The Brick-yard
Category: T3 Section
Forum Name: T3 Tech help
Forum Description: Forum for T3 specific problems.
URL: http://www.brick-yard.co.uk/forum/forum_posts.asp?TID=85744
Printed Date: 23 Apr 24 at 20:01
Software Version: Web Wiz Forums 12.06 - https://www.webwizforums.com
Topic: 1.9Tdi MAF Sensor Help
Posted By: mike1978
Subject: 1.9Tdi MAF Sensor Help
Date Posted: 22 Jul 14 at 21:11
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Hi, The van i bought recently has a 1.9TDI conversion in it. Its been running really flat and just doesn`t pull well at all. I took it to a local garage i know and we spotted the problem with his computer hooked up to it. The monkey who fitted the engine didn`t bother fitting a MAF sensor for some unbeknown reason. Now i`m going to be converting it to a subaru engine, but not for a few weeks yet. The thing is we were meant to be travelling into france in it in 2 weeks time, but i can`t go with it running like this. We`ll have to travel in our mk4 golf instead. I`d much prefer to go in the van, but need to sort this problem. Has anyone else fitted a 1.9TDI into their van? Which MAF sensor did they fit and how - most importantly, how did they wire it into the ECU? I don`t even know where to start with that! The engine is from a 2000 Skoda Octavia and is the 90bhp engine. with the flyby wire throttle. Any help much appreciated! Thanks, Mike ------------- --------- 1989 T3 Bluestar AFN TDi Flipped Gearbox |
Replies:
Posted By: youthy giblets
Date Posted: 22 Jul 14 at 21:39
| If you don't have a MAF fitted it can cause poor running and lack of power. The MAF itself is only 5 or 6 wires. Is the ecu loom easy to get to? It wouldn't take much to solder a bit of 6core cable on to the the loom and the MAF plug to get you away. We're there any other fault codes present? Seems strange that someone would connect up the diagnostic plug and not connect a MAF. Any pics?? |
Posted By: mike1978
Date Posted: 22 Jul 14 at 21:50
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yep - i can`t beleive they went to all the trouble and didn`t fit one. You could see on the computer, as you revved it up, the air flow stayed constant (at 550 i think, whatever that is!) The whole loom is there with the ecu and dash clocks aswell. The odbc connector is there and shows 4 codes - can`t remember exactly as we checked at the garage - the most significant though was vehicle speed sensor. The ecu is very accessible - i`m trying to find a wiring diagram online somewhere at the moment. I `ll see if can get some pics in a min. The air intake is a K and N airfilter which connects down the to the turbo area. There is a boost monitor there - let me see if i can get some pics. ------------- --------- 1989 T3 Bluestar AFN TDi Flipped Gearbox |
Posted By: mike1978
Date Posted: 22 Jul 14 at 22:33
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Managed to get some pics - its a bit dark. There is one sensor in the intake - i`m not sure if its a boost sensor or maf (or map?) sensor. The ecu is easily accessible as is the rest of the loom etc. I also found some notes about the ecu wiring that came with the van - it mentions - 4 - MASF (brown) 25 - MASF (Brown/Blue) 50 - MAFF (Red/Green) there`s a whole bunch of sensors tied up (you can see in the pic)      ------------- --------- 1989 T3 Bluestar AFN TDi Flipped Gearbox |
Posted By: mike1978
Date Posted: 22 Jul 14 at 22:37
       ------------- --------- 1989 T3 Bluestar AFN TDi Flipped Gearbox |
Posted By: mike1978
Date Posted: 23 Jul 14 at 08:09
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I think i have located the plug for the MAF sensor -
In the tangle of wires, i found this which looks like the plug on a skoda how to page -  and also seems to roughly match the wires mentioned in the notes i`ve got. Might see if i can get hold of a maf sensor and see what happens if i plug it in. What bugs me, is why they didn`t fit it - did the engine run worse fit it fitted possibly? ------------- --------- 1989 T3 Bluestar AFN TDi Flipped Gearbox |
Posted By: syncroandy
Date Posted: 23 Jul 14 at 08:49
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That's a shockingly poor TDI install you've got there. Your N18 (EGR valve) and more importantly N75 (turbo boost control valve) don't appear to be doing anything. I'm guessing the turbo isn't even the right one for the engine, possibly a JX one ?? Without the MAF the ECU wouldn't know the turbo was wrong as it can't see the airflow. With the MAF, it'll probably start complaining about inlet air pressure deviation as it'll realise summat isn't right with the turbo. What sump is fitted ? AFAIK the JX one won't fit to that later block. If the original sump is still there god knows how you're getting any oil into the engine reliably with it sitting at 55 degrees instead of 15. ------------- '90 252 EJ25 '90 246 AFN http://syncrosport.com" rel="nofollow - Syncrosport Volkswagen Transporter, reloaded. |
Posted By: mike1978
Date Posted: 23 Jul 14 at 08:57
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Yes - its not the best! I think its got a JX turbo fitted, but not 100%. I`m thinking they did a MAF originally, but then ran into problems because of the other things you mention. Which is the turbo boost control valve? would that normally connect to the turbo? The EGR valve - where would that normally go? I `ve had it less than a week and already had a turbo pipe blow off due to bad conenctors and clips and one of the main rubber connectors to the front radiator pipes just randomlly popped off while sitting there idling! I `d just like to get it running reasonably for the couple of months until i can get the wiring for the subaru sorted by richard at rjes (he has a waiting list!)  Here` s a link to the last subaru conversion i did a few years back now to an LLE i had if anyone is interested. http://www.vwkd.co.uk/bb/viewtopic.php?t=1561" rel="nofollow - http://www.vwkd.co.uk/bb/viewtopic.php?t=1561
------------- --------- 1989 T3 Bluestar AFN TDi Flipped Gearbox |
Posted By: mike1978
Date Posted: 23 Jul 14 at 09:01
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oh - yes, the sump is hand made - all lots of plates welded together. I`ll get some pics of that tonight when its a bit more light. ------------- --------- 1989 T3 Bluestar AFN TDi Flipped Gearbox |
Posted By: jim potter
Date Posted: 23 Jul 14 at 09:10
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WOW .. as has been said you are missing important things that should be connected . if your using a jx turbo and no maf i'm surprised it drives . you will probably have a load of stored fault codes . can you read any part no's from the turbo .. have you got a boost gauge fitted ? what does a jx turbo push 6-8psi ? i hope you get it all sorted .. sounds like you have good plans for it . ------------- Full vcds ,vag tacho, immo removal ( postal service avalible ), ecu remapping , spanners and a garage for anyone that wants any help, kettle always on. |
Posted By: syncroandy
Date Posted: 23 Jul 14 at 09:47
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Ah right.. apparently you can get away with the JX turbo on an MTDI, but on an eTDI the ECU is wanting to control things with more precision. Which is the whole point of eTDI really.. I suppose you could try running the JX turbo wastegate from the TDI N75, might be better doing this than leaving it uncontrolled. Re. valves, in your pic, the N75 has the metal body, the N18 has the plastic one. Most folk don't fit the EGR system to TDI conversions, so the N18 valve is left connected (to suppress a fault code) and hidden away somewhere or else replaced with a resistor to keep the ECU happy. Re. plumbing, there will be good diagrams out there, just make sure its correct for your engine. Interesting link to VWKD, I've used it as well, did my EJ25 conversion a few months after yours in late '08. I did my own wiring, obviously. ------------- '90 252 EJ25 '90 246 AFN http://syncrosport.com" rel="nofollow - Syncrosport Volkswagen Transporter, reloaded. |
Posted By: mike1978
Date Posted: 23 Jul 14 at 09:51
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Hi - yes, I can check the part numbers. There is a boost guage actually which tops out at about 8psi. When the turbo hose came off the other day, I noticed because the guage was no longer showing boost - the performance was hardly affected! ------------- --------- 1989 T3 Bluestar AFN TDi Flipped Gearbox |
Posted By: jim potter
Date Posted: 23 Jul 14 at 10:05
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Have you got the ecu part no. Can you post it here. ------------- Full vcds ,vag tacho, immo removal ( postal service avalible ), ecu remapping , spanners and a garage for anyone that wants any help, kettle always on. |
Posted By: syncroandy
Date Posted: 23 Jul 14 at 10:37
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ECU looks like 038 906 018 GM, the 'latest' version used on the Octavia AGR, it's 80-pin possibly with Canbus as its late. ------------- '90 252 EJ25 '90 246 AFN http://syncrosport.com" rel="nofollow - Syncrosport Volkswagen Transporter, reloaded. |
Posted By: mike1978
Date Posted: 23 Jul 14 at 11:34
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thanks guys for the help - i`ll see if i can also grab the ecu number tonight. I`ll also have a good look at the turbo to see what i`m looking at and if its possible to connect up that N75 to the JX turbo wastegate. I`ve also ordered a ODB2 bluetooth connector which will give me any codes, etc. It`ll come in handy for my subaru conversion anyway. I don`t really want to spend any money getting going given that i`ll be replacing it, but will see if i can get somewhere by trying to get the plumbing right. cheers, MIke ------------- --------- 1989 T3 Bluestar AFN TDi Flipped Gearbox |
Posted By: mike1978
Date Posted: 23 Jul 14 at 12:54
I found this diagram with the EGR valve removed -  And this one with everything including a N239 -  In the first diagram where the EGR and N239 are eliminated, he routes the turbo control valve to a vacuum with a one way valve - wheres best to take this on the T3? Also, what is the N239 - do i have one these or need it? Guess i`ll be off to our local scrappy on saturday morning to find an airbox and maf sensor! Cheers, Mike ------------- --------- 1989 T3 Bluestar AFN TDi Flipped Gearbox |
Posted By: mike1978
Date Posted: 23 Jul 14 at 12:57
I also found this diagram which is pretty good too -  ------------- --------- 1989 T3 Bluestar AFN TDi Flipped Gearbox |
Posted By: syncroandy
Date Posted: 23 Jul 14 at 13:16
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No, they're no good, your wastegate turbo is operated by pressure, not vacuum. Edit: From the manual:  ------------- '90 252 EJ25 '90 246 AFN http://syncrosport.com" rel="nofollow - Syncrosport Volkswagen Transporter, reloaded. |
Posted By: mike1978
Date Posted: 23 Jul 14 at 13:25
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Ah - ok, i`m all a bit new to TDIs, turbos and wastegates! So the Skoda (it an AGR by the way) turbo is operated by vacuum while the JX turbo is operated by pressure (air or mechanical?) Sorry for the questions - Thanks ------------- --------- 1989 T3 Bluestar AFN TDi Flipped Gearbox |
Posted By: syncroandy
Date Posted: 23 Jul 14 at 13:47
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No, wastegate turbo control uses inlet manifold pressure, VNT's use vacuum. Your 90hp AGR is a wastegate system. The JX is also a wastegate turbo controlled by boost pressure, but uses simple negative feedback, not ECU controlled like the TDI. ------------- '90 252 EJ25 '90 246 AFN http://syncrosport.com" rel="nofollow - Syncrosport Volkswagen Transporter, reloaded. |
Posted By: mike1978
Date Posted: 23 Jul 14 at 14:51
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Ah, ok, i think i understand - both the AGR and JX are wastegates controlled by pressure. The diagrams i listed are for turbos controlled by vacuum. I need to find a diagram for the AGR system. My Mk4 1999 Golf has a 1.9tdi 90bhp and may be the same engine - i`ll take a look and if it is, this may help me (i think!) ------------- --------- 1989 T3 Bluestar AFN TDi Flipped Gearbox |
Posted By: mike1978
Date Posted: 23 Jul 14 at 14:56
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I think this is the right diagram on this page - http://forums.tdiclub.com/showthread.php?p=4556321" rel="nofollow - http://forums.tdiclub.com/showthread.php?p=4556321 ------------- --------- 1989 T3 Bluestar AFN TDi Flipped Gearbox |
Posted By: syncroandy
Date Posted: 23 Jul 14 at 15:45
------------- '90 252 EJ25 '90 246 AFN http://syncrosport.com" rel="nofollow - Syncrosport Volkswagen Transporter, reloaded. |
syncroandy wrote:Posted By: mike1978
Date Posted: 23 Jul 14 at 16:09
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Perfect - thank you ------------- --------- 1989 T3 Bluestar AFN TDi Flipped Gearbox |
Posted By: youthy giblets
Date Posted: 23 Jul 14 at 16:15
| Sorry to be nasty but that is one horrific install. Sounds like you could be chasing your tail a lot to put that right. I'm suprised it runs in anything other than limp mode to be honest. |
Posted By: mike1978
Date Posted: 23 Jul 14 at 16:47
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To be honest, i completely agree with you. I`ll probably have a look at hooking the boost control valve up and a MAF sensor from the breakers to see if it`ll drive any better temporarily until i find myself an EJ25 engine. If it doesn`t, i`ll cut my losses and just drive it as is until then. Its a shame because the engine sounds really smooth, starts well - i`ve got the full service history from the original car and if the conversion had been done better, i`m sure it would`ve been good. I was just looking at Andys TDI Harness conversions on his page - if i`d done the conversion, i would`ve used something like that and the correct turbo etc. ------------- --------- 1989 T3 Bluestar AFN TDi Flipped Gearbox |
Posted By: jim potter
Date Posted: 23 Jul 14 at 17:06
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dont write it off just yet . hook up the maf and some form off boost control and see whats what . with the egr solenoid leave it connected but blank off the ports , it should not throw a fault code . i'm sure a weekend of redoing things would result in a much improved setup. IMO depends on how far you want to go really, if your dead set on a scooby lump , then spend as little as you need to , to have it run right but safe . ( that may be quite alot ) however you may then find the engine you have now once properly setup does the job you want . and remember power/trq upgrades on these yield good results . ------------- Full vcds ,vag tacho, immo removal ( postal service avalible ), ecu remapping , spanners and a garage for anyone that wants any help, kettle always on. |
Posted By: mike1978
Date Posted: 23 Jul 14 at 19:33
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Right - i had a good look under the engine tonight, but first, i had a quick look at my mk4 golf engine and it turns out it is also an AGR 1.9tdi and i can the 3 sensors i have all connected into the vacuum hoses. There is the EGR , boost control valve and another (not sure about that one). Here is a pic of the golfs turbo and where the vac pipes enter it on the top and there is also one underneath which looks like it would operate a lever.  The turbo on the van is a VW one and says KKK on the side - i tried to take a pic of the parts number on the side too. I can`t see any vacuum hoses attached, but there is a hard line attached to part of it which goes to the other side of it. Pics -    Here`s some other pics of the engine inlcuding the ecu number, an extended dipstick, the sump, intercooler, and other general pics -      ------------- --------- 1989 T3 Bluestar AFN TDi Flipped Gearbox |
Posted By: mike1978
Date Posted: 23 Jul 14 at 19:36
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double post
------------- --------- 1989 T3 Bluestar AFN TDi Flipped Gearbox |
Posted By: busbuddy
Date Posted: 23 Jul 14 at 19:48
im surprised there are only 4 codes flagged up by the ecu  i would also be looking at the front end to see if the throttle/brake/clutch switches are all present and proper as well ------------- http://www.karmann-coachbuilts.com" rel="nofollow - Karmann |
Posted By: jim potter
Date Posted: 23 Jul 14 at 19:51
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well on the plus side , hard bits done . id be looking to take apart and redo pipework , remount intercooler . tidy up the wiring etc . how many miles have you done in it so far, as the oil return looks very low into the sump .. it looks like you have a kkk14 turbo . good for a bar of boost .. seems the agr turbo also does around a bar peak . so id look at controlling the boost to 1 bar manually ( you could adjust wastegate or use a manual bleed valve ) at peak, with the maf. that should give you some improvement and match what it should have. ------------- Full vcds ,vag tacho, immo removal ( postal service avalible ), ecu remapping , spanners and a garage for anyone that wants any help, kettle always on. |
Posted By: mike1978
Date Posted: 23 Jul 14 at 20:25
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Yes, everything else on the van is pretty good - my main concern when buying the van was the exterior to have minimal seam rust and the interior to be good aswell, both of which are. Brakes, handling and steering are all pretty good too. The engine wasn't my main concern as I knew that if be planning to replace it quite quickly with a scooby - been there and know it well :) The tdi was a bit of an unknown and surprise to be honest! Anyway, I've been having a think and for the time being I'm going to do what Jim suggests, up the max boost a little manually and fit the maf. I have a beetle to rebuild this weekend and then we're on holiday for s couple of weeks. When I get back, I'll crack on with the scooby conversion. I'll them sell the tdi conversion and I'm sure with a bit of time and patience the engine can be sorted :) there's not much point on me spending time getting it running well when I'll just take it out soon! Thank you for all the help and advice I imagine I'll start a build thread soon! Cheers, mike ------------- --------- 1989 T3 Bluestar AFN TDi Flipped Gearbox |
Posted By: mrhutch
Date Posted: 23 Jul 14 at 22:05
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Good lad.. and stop listening to the diesel junkies on here. we both know it's a lubricant, not a fuel. ------------- T3 1981 Westy Vanagon - thinks lubricant is a fuel |
Posted By: max and caddy
Date Posted: 24 Jul 14 at 00:52
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Nice.. Is the aircon pump doing anything? That can be deleted if not. Even your mk4 AGR will have pressure control on the boost regulation, the valves with vac pipes going to them are egr and the anti shudder flap, engine will run without those and often won't miss the egr on these engines...my missus has one currently at 260000 miles and its never been apart exept cambelts and about a million flywheels. Better than petrol/solvent powered units...they are obselete now really anyway. |
Posted By: mike1978
Date Posted: 25 Jul 14 at 19:29
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Right - i `ve decided i`m going ot have a go a getting this engine running properly. Its a good low mileage engine which runs nice and smoothly. As someone else said, most of the hard work has been done. At the very least, a properly running engine is easier to sell on and would fetch more money. So i`ve bought a maf sensor off ebay - my first step is to fit that. I `ve also gone round and checked all the jubilee clips - most were loose or knackered, so they`re all fixed now and tightened. My next question is regarding the turbo. Now i`ve always messed around with NA petrol engines, so these turbo diesels are a bit of a new thing for me, so bear with me! I`ve borrowed a wifi odbc connector thing which can connect to an app on my phone so i can read the codes and also monitor the engine - hopefully that`ll work. I`ve done a bit of reading and understand what the waste gate does and the vacuum pipe attached to the standard turbo regulates the opening of it so the boost doesnt get too high. Should i attempt to connect the boost control valve to the JX KKK turbo? If so, i can`t see any vacuum ports on it - is there a way to connect it up? Does the JX KKK turbo not have the facility to connect a controller up to it and is normally set manually to a set max pressure? If that is the case, how do i adjust the max boost on the JX KKK turbo? Should i then just blank off the vaccum pipes on the boost control valve and egr valve to 'trick' them into thinking they are working? I think thats enough for starters! So i`ll see where i go from here. I should get chance to take a look at this on sunday. Cheers, Mike ------------- --------- 1989 T3 Bluestar AFN TDi Flipped Gearbox |
Posted By: mike1978
Date Posted: 25 Jul 14 at 21:05
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I`ve also ordered a correct for the engine second hand AGR turbo off the ebay - if its not right for what i want, i can always resell it. I can only think that running the correct turbo for the engine has got to be a good thing. ------------- --------- 1989 T3 Bluestar AFN TDi Flipped Gearbox |
Posted By: monkey magic
Date Posted: 25 Jul 14 at 21:14
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cough mtdi it cough was going to slip in a solvent comment for Hutch but max beat me to it. hope you get her running right either way, the 19 tdi s are perfect for these vans. and i agree about sticking a decent turbo on, i know the jx units work but its a step backwards in my book ------------- mTDI Syncro |
Posted By: mike1978
Date Posted: 25 Jul 14 at 21:26
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is m-tdi sticking on a fuel pump from a non tdi engine? You can then get away with throwing away all the ecu , wiring, etc and also run the throttle cable straight to it? Or have i got the wrong end of the stick!? ------------- --------- 1989 T3 Bluestar AFN TDi Flipped Gearbox |
Posted By: monkey magic
Date Posted: 25 Jul 14 at 22:08
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not so much pump from a non tdi, just non electronic. otherwise yes. many people assume all tdis are electronic, not so. tdi stands for turbodiesel direct injection, nothing to do with electronics, just about direct injection.
------------- mTDI Syncro |
Posted By: youthy giblets
Date Posted: 25 Jul 14 at 22:22
| Stick with the wiring and try and sort it. If I were you I'd try getting the MAF sorted and lose as many fault codes as you can. Put a proper turbo on it and then if your happy send that big bundle of shite off to Andy and get a pukka loom back in return unless your handy with wiring yourself |
Posted By: andypandy1930
Date Posted: 25 Jul 14 at 23:08
| Can you use relays instead of the brake switches on the pedals! |