Crickleymal Posted January 29, 2012 Report Posted January 29, 2012 (edited) Alhambra 1.9TD 1997 I appear to have a problem with either my turbo or the EGR valve. If I give it some welly the engine revs up to 3000 rpm then goes flat i.e. limp home mode. Switching it off an back on seems to fix it for a short while. I tried putting some Forte cleaner in the tank but to no avail so far. I bought some EGR valve blanking plates off ebay and fitted one to the exhaust side of the valve this morning. Took it out for a run and if anything it's worse now. Although it only seem to happen if I give it welly in 4th and 5th. 2nd and 3rd seem ok. I have seen on an Audit forum http://www.audi-sport.net/vb/a4-s4-forum-b5-chassis/107121-un-sticking-your-tdi-vnt-turbo-vanes.html that using Mr Muscle foaming cleanser on the exhaust side of the turbo might fix it but a) it seems to be a right swine to get to the turbo and b] obviously I'm a bit nervous about doing this. Does anyone have any other ideas please? Malc Edited January 29, 2012 by Crickleymal Quote
seatkid Posted January 29, 2012 Report Posted January 29, 2012 (edited) Does anyone have any other ideas please? Its much more likely its a duff MAF sensor. If you get a new one, make sure its the right one for your engine. We have cases on the forum of people buying from fleabay and even Eurocarparts and thinking they eliminated the sensor - but they got a wrong/not working one. They are about £90 from dealers (phone around - VW seem cheapest), I would also try GSF provided they can guarantee its the correct part no. If yours is a 110bhp, the vane actuator may be "sticky" and needs cleaning. 90bhp have a fixed geometry turbo and dont have a vane actuator. Try the MAF sensor first. Edited January 29, 2012 by seatkid Quote
Crickleymal Posted January 29, 2012 Author Report Posted January 29, 2012 (edited) Does anyone have any other ideas please? Its much more likely its a duff MAF sensor. If you get a new one, make sure its the right one for your engine. We have cases on the forum of people buying from fleabay and even Eurocarparts and thinking they eliminated the sensor - but they got a wrong/not working one. They are about Edited January 29, 2012 by Crickleymal Quote
seatkid Posted January 29, 2012 Report Posted January 29, 2012 Ok thanks. Mine is the 90bhp model. Where is the MAF sensor? The problem is a bit intermittent. It doesn't always happen, sometimes it can go for half a day without it happening then it will occur every time I get up to 3000 rpm. Oh yes one other thing - no engine management lights on. Malc The MAF sensor comes complete with housing - easy to take off One or two people claim to have cleaned the MAF sensor with success. It didnt work for me or plenty or others. If you insist on cleaning, then extract the sensor from the side of the housing. Quote
Crickleymal Posted January 29, 2012 Author Report Posted January 29, 2012 One or two people claim to have cleaned the MAF sensor with success. It didnt work for me or plenty or others. If you insist on cleaning, then extract the sensor from the side of the housing.Thanks. I took it out and didn't have any security screw bits so I couldn't extract it from the casing. I did swill it in paraffin but it made no difference. I might get my friendly mechanic to read the codes. Quote
seatkid Posted January 29, 2012 Report Posted January 29, 2012 (edited) Thanks. I took it out and didn't have any security screw bits so I couldn't extract it from the casing. I did swill it in paraffin but it made no difference. I might get my friendly mechanic to read the codes.The MAF sensor doesnt give any codes - its calibration drifts into oblivion and the ECU cannot detect whether the output is valid or not. On the other hand under/over boost trips due to faulty (vacuum) pipework or turbo control do give codes - but I think it'll be unlikely thats the problem in your case. Edited January 29, 2012 by seatkid Quote
f0ster Posted January 30, 2012 Report Posted January 30, 2012 Hello I had the same year and model of galaxy with the exact same fault, it occours because the ecu is detecting overboost, I was lucky enough to be working in mazda garage at the time, the mazda diagnostic machine was the same as the ford one, so we were able to view all of the parameters while driving, it turned out the boost pressure was fluctuating which would then occasionally take it over the top which was picked up by the ecu,the ecu would then go in to limp home mode, this can be reset by backing off the throttle and back on, on later ones you have to switch off the ignition, there is a pipe that goes from the manifold to the ecu that is behing the drivers instrument panel, the cure is not always easy, if you can get a maf sensor to swop with someone try that first,the boost pressure pipes can get blocked with oil that stops it getting clean signals,I checked the waste gate on mine and it was operating ok,the power is controlled by the waste gate hovering in mid position when the power gets up near the limit,I cannot remember if the waste gate is controlled by pressure or vacuum, Quote
seatkid Posted January 31, 2012 Report Posted January 31, 2012 Yes, good one, foster. The wastegate on the 90bhp AHU / 1Z is vacuum controlled. Any leaks in the control (small bore) vaccuum pipework generally cause an underboost fault (logged in the ECU). Common to have old vacuum pipes crack/split. The boost pressure is monitored by a pressure sensor located in the ECU. There is a small diameter pipe going from the boost/intercooler pipework at the gearbox end of the engine, behind the engine and through the bulkhead down on the drivers side. Behind the dash it goes to the ECU which is located behind the dash on post 98 models or (IIRC) under the drivers seat (not sure) on pre 98 models. The rubber pipe bit that goes into these early ECUs often goes squidgy and gets blocked internally - leading to overboost faults (again logged). I think there is a detailed explanation and maybe a couple of photos somewhere on the forum regarding this ECU boost sensor pipe. Quote
Crickleymal Posted January 31, 2012 Author Report Posted January 31, 2012 (edited) Well I tried a new MAF sensor (Bosch so the same sort as the one I took off). It's made no difference. Where do I plug in the code reader? Someone has leant me one but don't know where it goes or even if his (RAC ODBC)will connect. I did notice a little cloth covered tube (about 3mm internal diameter) leading from the plastic pipe (about 50mm diameter) coming up from under the front of the engine was worn through. I cut out the worn section at the same time as I replaced the fuel filter and then all this trouble started. The problem only happens in 4th or 5th gear. Edited January 31, 2012 by Crickleymal Quote
seatkid Posted January 31, 2012 Report Posted January 31, 2012 (edited) I did notice a little cloth covered tube (about 3mm internal diameter) leading from the plastic pipe (about 50mm diameter) coming up from under the front of the engine was worn through. I cut out the worn section at the same time as I replaced the fuel filter and then all this trouble started.Ah pity you didnt mention that earlier! This is the boost pressure feed to the boost sensor located in the ECU. The connector for diagnostics is located in the centre ashtray - pull it out and you will see it underneath going forward. Sorry the MAF sensor didnt sort it. (Dont suppose you'll be able to take it back?) I should have taken more notice of the fact that you said the problem was intermittent, which the MAF sensor wouldnt give. Mea Culpa! Looks now increasingly likey its the fault that Foster says with the boost pipe being blocked or split somewhere else - as he says a few people have said that the ECU end gets all manky probably due to oil contamination from the boost pipework. Edited January 31, 2012 by seatkid Quote
Crickleymal Posted January 31, 2012 Author Report Posted January 31, 2012 I did notice a little cloth covered tube (about 3mm internal diameter) leading from the plastic pipe (about 50mm diameter) coming up from under the front of the engine was worn through. I cut out the worn section at the same time as I replaced the fuel filter and then all this trouble started.Ah pity you didnt mention that earlier! This is the boost pressure feed to the boost sensor located in the ECU. Well As I cut out the manky bit I assumed that it would be ok. The bit I removed had a hole in it so I cutout the section with a hole and replaced it where I found it. I'll go and have another look at it. If I disconnect it i.e. replace the hole the problem should go away yes? Quote
Crickleymal Posted February 1, 2012 Author Report Posted February 1, 2012 (edited) 31/1/12 And the answer is yes. Removed pipe and let it dangle where it was. Went out for a spin and no limp home mode. The car does seem pssibly slighty less responsive but on the other hand it's now back to where it was before I repaired it. 1/2/12 Well almost fixed. Coming down the motorway it was fine until I sat at 50 mph in the roadworks. Then it switched to limp home but as I was only doing a couple of thousand revs I didn't notice it until I tried to accelerate afterwards. Switched off and back on and it was fine for the next 15 miles Edited February 1, 2012 by Crickleymal Quote
seatkid Posted February 1, 2012 Report Posted February 1, 2012 I'm surprised. You normally need to have this pipe connected to get full performance, with it disconnected I would expect it to go into limp home mode almost permanently. Quote
Crickleymal Posted February 1, 2012 Author Report Posted February 1, 2012 (edited) I'm surprised. You normally need to have this pipe connected to get full performance, with it disconnected I would expect it to go into limp home mode almost permanently. Well now it does go into limp home mode I have discovered, either when the engine is working really hard (which can be mighty inconvenient I can tell you) or just at random when you can't tell. Disconnecting the pipe seemed to make it better but now I'm not so sure. I would say the probelm is worse with a hot engine but as I don't drive it hard until it's warmed up.... I tried a friends code reader at lunchtime but it was ODB2 and wouldn;t connect. So I'm getting my friendly local mechanic round on Monday as his place has an all singing all dancing code reader. It's probably something really stupid and obvious but I just can't see what at the moment. Edited February 1, 2012 by Crickleymal Quote
chrispb123456 Posted February 2, 2012 Report Posted February 2, 2012 You may find this helpfull if you decide to have your engine ECU out.http://www.fordgalaxy.org.uk/ford/index.php?/topic/22717-how-to-ecu-removal/page__p__164798__fromsearch__1#entry164798 Quote
Crickleymal Posted February 2, 2012 Author Report Posted February 2, 2012 You may find this helpfull if you decide to have your engine ECU out.http://www.fordgalaxy.org.uk/ford/index.php?/topic/22717-how-to-ecu-removal/page__p__164798__fromsearch__1#entry164798 Oh that makes me feel sooo much better :) Any idea where I can find the engine code i.e. the type of engine just so I can be sure I'm getting the correct stuff? Thanks Quote
Crickleymal Posted February 6, 2012 Author Report Posted February 6, 2012 Ok I've had the codes read and the only fault is the MAP sensor. This is at the other end of the pipe I repaired I presume? Is it easily get atable? Thanks Malc Quote
chrispb123456 Posted February 6, 2012 Report Posted February 6, 2012 The MAP sensor is inside the engine ECU, have already sent you a link to the how to remove ECU on page one thread 15 Quote
Crickleymal Posted February 6, 2012 Author Report Posted February 6, 2012 The MAP sensor is inside the engine ECU, have already sent you a link to the how to remove ECU on page one thread 15Yes I did see that thanks. A quick google for Alhambra MAP sensors showed only one or two versions so I was hoping it was a separate entity. Oh well a job for the weekend Ifear. Malc Quote
chrispb123456 Posted February 6, 2012 Report Posted February 6, 2012 The MAP sensor is inside the engine ECU, have already sent you a link to the how to remove ECU on page one thread 15Yes I did see that thanks. A quick google for Alhambra MAP sensors showed only one or two versions so I was hoping it was a separate entity. Oh well a job for the weekend Ifear. Malc Only the PD engines have the MAP sensor in the air charge pipe from the intercooler. Quote
Crickleymal Posted February 6, 2012 Author Report Posted February 6, 2012 Only the PD engines have the MAP sensor in the air charge pipe from the intercooler. One last quick question. If I blow down the pipe leading to the MAP sensor there is very little resistance. I would have thought that if you were sensing pressure the pipe would feel like a dead end. SO presumably (hopefully) the pipe is split and not the senosr damaged? Malc Quote
chrispb123456 Posted February 7, 2012 Report Posted February 7, 2012 Could be the pipe from engine to the ECU or the short piece inside the ECU split Quote
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