Paul McKenzie Posted October 2, 2003 Share Posted October 2, 2003 Regarding sealant, guys, I think I would try and get one which was free of acetic acid. You've probably noticed that regular bathroon silicone sealants give off a lot of vinegar while they're curing. Just a thought... but the acid is very corrosive. Paul Link to comment Share on other sites More sharing options...
Steve Kirk Posted October 3, 2003 Share Posted October 3, 2003 Some more info in case this helps anyone else later. I took my ECU apart again to give it a closer look and clean. I noticed that although the harness plug itself is well sealed around the pins, there are quite large gaps of about 5mm between the plug and the case. There was in fact a thin film of dirt on the front part of the circuit board where the harness plug is soldered, I think on closer examination that this was air-borne given that there is no corrosion at all in that area, even of the case. Overall, although there were only small areas of corrosion inside the case, the majority of it (and therefore presumably water ingress) was on the RH side of the case, i.e. the side nearest the outside of the car. Also it looks as though the circuit board is not lacquered, which confirms JonP's comment below. Luckily there is no trace of corrosion on the circuit board itself - just the case. I also called CC to seek their advice. They told me that the spacers were fitted on later cars purely to lift the ECU up to make space for the MFRU, so that the two can be installed together neatly. It's nothing to do with avoiding water. In fact they did not recall receiving any reports of water entering ECUs before. However they thought that using the later spacers to lift up the ECU might be worth a try, given the specific problems that I have had in my car. They had mixed feelings about sealing the ECU, given that it was not sealed in the first place - for similar reasons to those mentioned already in this thread. They also mentioned that they have ECU diagnostic equipment at the factory for VX cars, and offered to test my car for me if I called them and brought it over. I must say that I found the guys at CC extremely helpful on this. They answered all my questions, took a genuine interest, and gave genuine practical advice. Given that my car is 8 years old and long out of production, I think that this is outstanding service. I even got a call back from Jez Coates after hours to make sure that my earlier question had been answered before the day was out. Link to comment Share on other sites More sharing options...
JonP Posted October 3, 2003 Share Posted October 3, 2003 Hi Steve, Re your photo, yes correct, although the whole assembly seems mounted upside down compared to mine, not that it matters. The 10 pin socket is for diagnostics, the three pin is for the octane plug, the plug itself is brown item held in clip. The ECU can report more than one fault, it just sends them out one after the other, so if you had say code 25 AND code 38 you would see 2 flashes, short pause, 5 flashes, longer pause, 3 flashes, short pause, 8 flashes, longer pause, 2 flashes etc and round again. Codes 12 All clear 13 Oxygen sensor O/C 14 Coolant temp low 15 Coolant temp high 16 Knock sensor 1 17 Knock sensor 2 18 Knock control module 19 Incorrect RPM 21 Throttle pot high 22 Throttle pot low 25 Injector 1 voltage high 26 Injector 2 ditto 27 Injector 3 ditto 28 Injector 4 ditto 31 No RPM signal 32 Fuel pump relay volts high 38 Oxygen sensor weak 39 Oxygen sensor rich 48 Battery voltage low 49 Battery voltage high 52 Engine check light voltage high 53 Fuel pump relay volts low 54 Fuel pump relay volts high 55 ECU fault 56 Idle control voltage low 57 Idle control voltage high 61 Fuel tank vent valve voltage low 62 Fuel tank vent voltage high 71 Intake air temp volts high 73 Air flow sensor voltage low 74 Air flow sensor voltage high 75 Torque control voltage high 79 Full load inhibitor voltage low 81 Injector 1 voltage low 82 Injector 2 ditto 83 Injector 3 ditto 84 Injector 4 ditto 87, 88 aircon relay fault (!) 93 Hall sensor low 97 Ignition/injection cut off voltage high The octane plug selects one of two maps. These are easily recognised because one map gives an idle of approx 1100rpm (and a bit better midrange) and the other map gives idle at 1000rpm and smoother running. I use the second map. JonP No longer Sevenless....! Link to comment Share on other sites More sharing options...
Steve Kirk Posted October 3, 2003 Share Posted October 3, 2003 Thanks again Jon, useful stuff. Link to comment Share on other sites More sharing options...
JonP Posted October 5, 2003 Share Posted October 5, 2003 Hi Steve, Before I sound like I know what I'm talking about...went down to the new forest today and the problem is still there despite the ECU reporting all clear when I got home. So either its not the ECU, might try a new set of ignition leads I think OR the ECU is so corrupted it can't remember whats going on. Actually wonder if its the Vecta playing up....More fun! 'My' fault is that you can be driving along with full load or no load on the engine...and it momentarily cuts as if the ignition has gone off, the ECU light comes on, and then the power comes back and eventually the ECU light goes out. Then its all OK till the next time. A complete bar steward in other words. Thoughts anybody in internet land? Cheers JonP No longer Sevenless....! Link to comment Share on other sites More sharing options...
Steve Kirk Posted October 6, 2003 Share Posted October 6, 2003 Jon You might also be interested in pages 9-12 of this here PDF doc - it seems to give an extended fault code list for the 2.8 motronic ECU...? It also mentions that ECU light has to be on for >30 seconds before a fault is logged, otherwise it is ignored as "intermittent", maybe that's the problem you're having? PS I found this page by doing a google seach based on one of the fault codes in your list above, e,g, "31 No RPM signal motronic", this turns up other related pages too. Other useful pages were here and here. PS I haven't experienced the symptoms you're seeing exactly, but on just 1 or 2 occasions in the 2 years I've had the car I can recall diving along and pressing the accelerator and getting very flat response in the midrange, i.e. it was as if there was no power. This usually happened just once for a few seconds, then the engine would pick up again. Haven't had that for several months now though. Link to comment Share on other sites More sharing options...
JonP Posted October 6, 2003 Share Posted October 6, 2003 Hi Steve, Thanks fo the extra info. I think part of my problem maybe that the flow meter electronics were positioned very close to the coil pack at the back of the engine. I've now turned the flow meter so that there is 2-3inches between the coil and the sensitive flow meter electronics. Just need to find time to test it now! Cheers JonP No longer Sevenless....! Link to comment Share on other sites More sharing options...
JonP Posted October 11, 2003 Share Posted October 11, 2003 Re Flow meter position...that seems to have fixed it....famous last words... JonP No longer Sevenless....! Link to comment Share on other sites More sharing options...
Steve Kirk Posted November 3, 2003 Share Posted November 3, 2003 Jon, hope your car is now healthy. Mine was going superbly for a few weeks, but unfortunately, the problem has come back after the rain last week. I think what I need to try next is someone who is a specialist in this sort of thing, i.e. hard to diagnose intermittent starting/idling problems on cars with engine management systems (i.e. both elec ignition and injection). I've asked the people who I normally trust with my car to have a look already, but to be fair none of them would pretend for a second to be EMS specialists, and the fault is very annoyingly intermittent. If anyone could please recommend someone with a relevant track record in this sort of stuff, I'd be very grateful. I know that there are several reputable people out there who we all know are knowledgeable and trustworthy on 7s in general - but what I don't know is whether any of those has a particular track record in solving this sort of problem, or whether the answer lies with a specialist in engine management rather than in 7s - if so, who?? Thanks. Steve. Link to comment Share on other sites More sharing options...
Steve Kirk Posted December 29, 2003 Share Posted December 29, 2003 My car has continued with this problem ☹️ however the good news is that I now know what the fault is - definitely a dodgy ECU. We confirmed this at the last breakdown by taking the circuit board out of its case and drying it with a hairdryer - the car ran perfectly straight away. The thing dying all the time now at the slightest hint of moisture in the air so I need to replace it. However they cost about a million pounds new. Does anyone a used one in their cupboard please? One club member has already kindly lent me two spare units to try out, but they have turned out not to be quite the right type. The details shown on the sticker on the case of my failed unit are: Bosch number: 0 261 203 019/020 GM number: 90 358 384 ID code: PT (in large letters about 1.5cm tall) I know from looking up part numbers that this is a Bosch Motronic 2.8 unit. It is in an aluminium case with a 55-pin harness connector. This is from a late model (post 93) car - this is the distributorless type, with a twin coil pack and cam sensor at the back of the cam covers, and no conventional coil. The car is now dead so I need to replace ASAP, so will pay courier charges etc in the interests of getting back on the road quickly. PS for future reference for anyone else having this problem, no liquid water has got into the ECU or its harness connectors the last few times this problem has happened - it seems to play up even when it has been in damp air conditions, such as overnight in the current winter weather. A quick blast with a hairdryer on the printed circuit board seems to make it happy again. I have also changed the fuel pump relay (the big one above/behind the ECU) as it appeared slightly damaged but this turned out to be a red herring. Link to comment Share on other sites More sharing options...
Paul McKenzie Posted December 29, 2003 Share Posted December 29, 2003 Steve, I have one that you can have for half a million pounds Give me a call and I'll get it to you Paul Edited by - Paul McKenzie on 29 Dec 2003 14:10:21 Edited by - Paul McKenzie on 8 May 2013 18:46:20 Link to comment Share on other sites More sharing options...
EFA Posted December 29, 2003 Share Posted December 29, 2003 I have a 90 299 569 disti one if this is of any use. FOC Fat Arn Slay the K. Link to comment Share on other sites More sharing options...
Steve Kirk Posted December 30, 2003 Share Posted December 30, 2003 Thanks Paul/Arnie. I have now received Paul's unit which he very kindly UPSed to me. Works a treat. Paul, I have emailed you separately. For the record for anyone with a similar problem, Pauls ECU was in a lot better external condition that mine, presumably because of spending its life under a cosy cavalier dashboard rather than a cold/wet caterham one. I plan to re-site the ECU under the scuttle to protect it now, otherwise I see it going the way of the old one and getting wet and corroded. Only glitch was that I couldn't plug it into the engine harness at first - then realised that new unit has a plastic lug on the LHS of the connector which was blocking the harness plug. Inspection of old (original Caterham) unit shows that same lug had been hacked off my old unit so did same to new one and problem solved. New unit also appears to log and remember faults, which old unit wasn't doing properly, e.g. if I unplugged the temp sensor it would not remember this as a logged fault, whereas new unit does. So I think the old one had been on the way out for some time. Another gotcha when trying to replace the unit through commerical suppliers is that the serial number is not listed on the Vauxhall parts computers - at least it wasn't at two separate places. Apparently according to the expert on these matters at one VX dealer, the two-letter "id code" is as important as the part number in identifying the application - apparently a similar unit can be wired totally differently depending on the engine variant. If anyone does want a new unit, I was quoted 700-800 quid by CC/ VX dealers. Recon available from Vauxhall dealers for about 300ish. All plus VAT of course. Or you can try atp electronics who test and remanufacture ECUs for loads of cars and are a bit cheaper (265 from memory). Have had them recommended. They have a useful website that contains useful info on ECUs too. Edited by - Steve Kirk on 30 Dec 2003 16:50:44 Edited by - Steve Kirk on 30 Dec 2003 16:52:27 Link to comment Share on other sites More sharing options...
Steve Kirk Posted January 13, 2004 Share Posted January 13, 2004 Some more info in case it's of use to others. Just spoke to ATP electronics who tested my old ECU, for more info about the test results. A few interesting bits of info: 1. These ECUs are prone to being effected by cold/damp. It effects the components over time. which makes the ECU malfunction. 2. They are lacquered (as discussed earlier in this thread), however over time it breaks down. Also if a previous owner has attempted to repel water off the board with WD-40, this actually dissolves the lacquer! 3. Commonly, the ECU's ability to switch the fuel pump relay dies first, then the ignition circuits die next. 4. In the VX saloons, the problem was commonly that water travelled down the harness and entered the ECU via the plug. 5. Sealing the ECU case can be a mixed blessing because condensation could form afterwards due to the heat generated inside. Link to comment Share on other sites More sharing options...
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