Martin R Posted May 7, 2009 Posted May 7, 2009 Matt, in that case all i can think of is the following. Check the resistance of the brown and blue temp sensors when cold. Warm the car up and make sure this reading is changing. Also check the resistance of the 2 VVC control solenoids. They should be the same. Checking the resistance will ensure one is not open circuit and therefore not working. Maybe someone with a S1 111s can check the resistance of these 2 solenoids to give you a comparison.
TheRon Posted May 7, 2009 Posted May 7, 2009 We checked the resistance of the 2 solenoids last night using a multi-meter. Both were 0 ohms indicating there is conductivity through the solenoid wires - as it should be with no load. I think Matt has already checked the resistance of the temp sensors changes (including the VVC oil temp sensor).
Martin R Posted May 7, 2009 Posted May 7, 2009 I would expect the resistance to be higher than 0 Ohms. It would take a hell of a lot of current at that. It would depend on the accuracy of the meter though. The only other suggestion i can think of its to put a code reader on it and see if it shows any faults. I think one or two on here have one.
Matt C Posted May 16, 2009 Author Posted May 16, 2009 Don't think the oil temp sensor is anything to do with it... it only looks at viscosity to anticipate VVC actuation speed. Going to take it to a MG specialist on Monday locally... anyone know where the ECU diagnostic plug is? I thought it was a plug in pax footwell but now not so sure!
Matt C Posted May 16, 2009 Author Posted May 16, 2009 Found diagnostics plug.. http://www.sandsmuseum.com/cars/elise/info...part_2_of_3.pdf
Guest Glen Posted May 18, 2009 Posted May 18, 2009 After talking to TGA the other week they recommended ATP Electronics for checking the ECU is working correctly. I've since contacted ATP and they can check the rover MEMS 2J ECU for £30. However, there's no surprise that they didn't recognise the Lotus part number. Does anyone have the Rover part number for the 143bhp EU2 ECU (not the revised 156bhp EU3 ECU)? And can anyone confirm whether this ECU was remapped by Lotus? I know they usually remap ECUs but the bhp and torque figures are the same for the MGF and the Elise. I apologise if this is thread drift - but I'm now fairly sure my rev limit is caused by the ECU and for £30 it would certainly be worth checking anyway.
Matt C Posted May 18, 2009 Author Posted May 18, 2009 After talking to TGA the other week they recommended ATP Electronics for checking the ECU is working correctly. I've since contacted ATP and they can check the rover MEMS 2J ECU for £30. However, there's no surprise that they didn't recognise the Lotus part number. Does anyone have the Rover part number for the 143bhp EU2 ECU (not the revised 156bhp EU3 ECU)? And can anyone confirm whether this ECU was remapped by Lotus? I know they usually remap ECUs but the bhp and torque figures are the same for the MGF and the Elise. I apologise if this is thread drift - but I'm now fairly sure my rev limit is caused by the ECU and for £30 it would certainly be worth checking anyway. Hi Glen, Rover part number could be MKC104000 or MKC104001, but not 100% sure. I spoke to TR Autos who are a MG Specialist, and they told me Lotus had remapped the top end, although not sure why as the power is the same. I am going to try and get the fault codes cleared in my ECU today and see what that does (either fixes it or generates new fault codes). Matt, would a faulty Lambada sensor cause this ? I asked myself this lastnight. Still not decided, but as the engine runs closed loop, and the engine runs ok (other than VVC), then I think it must be ok.
Guest Glen Posted May 18, 2009 Posted May 18, 2009 Hi Glen,I spoke to TR Autos who are a MG Specialist, and they told me Lotus had remapped the top end, although not sure why as the power is the same. I am going to try and get the fault codes cleared in my ECU today and see what that does (either fixes it or generates new fault codes). Good luck! I've had my fault codes cleared - except that the IAT fault could which would not clear. Hopefully your's is a different fault and you can fix/diagnose the fault this way. Could be please PM me there details and I'll have word with them to see if they can help me out. I asked myself this lastnight. Still not decided, but as the engine runs closed loop, and the engine runs ok (other than VVC), ten I think it must be ok. After comparing my engine to a standard one at Bedford the VVC is definately working - I was having to back off at 110mph on the back straight when I hit the rev limit but the standard k-series barely reached 110mph by the end if the straight. Don't forget that the Rover VVC varies timing throughout the rev range and is not like the Toyota/Honda which switch to a second cam at higher revs. Has anyone got a standard k-series you can compare it too?
Matt C Posted May 18, 2009 Author Posted May 18, 2009 Glen, I'm not sure thats right.... I'm sure the VVC isn't moving at all, thats why the rev limit is there to prevent valve bounce with the wrong cam duration. If it was moving then all would be fine. The VVC is not the only difference to a std 118bhp... intake system, head port design etc are all different. I'm going to see Roger in 1hr at TR Autos http://www.trautos.co.uk/index.html - will report back.
Guest Glen Posted May 19, 2009 Posted May 19, 2009 Matt, I'm by no means an expert, but the VVC is definitely has continuously variable timing throughout the entire rev range (clicky) - it's one of the advantages over the other VVT systems. That would also be why you saw 12v on both solenoids - they continuously adjust to keep the hydraulic actuator in check. If you used a fancy scope rather than a basic voltmeter you'd see that either one or the other was energised. But a basic meter would not pick this up. One of the reasons for the lower rev limit is to protect the engine when cold - although I would not have thought many people would be daft enough to red-line a cold engine,. I'd be interested as to why you came to the conclusion that the VVC was not working at all. I appreciate that the VVC mechs are not the only difference - the close ratio box alone will make a big difference on track. But I've had two separate garages say the VVC mechs are working and that my limit is due to the ECU/software. I'm by no means 100% convinced either way with mine as I have an innate distrust of most garages, but from what I understand I do believe that they are working OK. Hopefully your's is all sorted by now anyway...
TheRon Posted May 19, 2009 Posted May 19, 2009 I think Matt means that the VVC mechanism is not moving because the ECU isn't trying to move it and so he is restricted to a single cam profile - and therefore there is a rev limit to prevent damage due to running at high revs with a cam profile that is designed to work a low revs. The 12V on both solenoids is simply how the system is wired - the ECU connects one of the solenoids to earth to move the cam profile up or down. A solenoid is either activated or not they are not continuously variable devices - rather the length of time the solenoid is activated determines how much the cam profile is changed by.
Guest Glen Posted May 19, 2009 Posted May 19, 2009 The VVC doesn't have choice of cams like the VTEC systems - it's continuously variable and does not switch! The VVC is a lot more complicated (clicky)
TheRon Posted May 19, 2009 Posted May 19, 2009 Solenoids are not continuously variable devices. In order to continously control the cam profile the solenoids are activated to either 'wind up' the profile or 'wind down' the profile. If the VVC solenoids are not activated then the cam profile will not change. The length of time the solenoids are activated for will determine how much the profile is 'wound up' or 'wound down'.
lummo Posted May 19, 2009 Posted May 19, 2009 Solenoids are not continuously variable devices. In order to continously control the cam profile the solenoids are activated to either 'wind up' the profile or 'wind down' the profile. If the VVC solenoids are not activated then the cam profile will not change. The length of time the solenoids are activated for will determine how much the profile is 'wound up' or 'wound down'. I'm no expert, but the way I understand it is that the cam profile doesn't change on the 'K' series VVC. It is the duration of the inlet valve opening that changes. This is controlled by an eccentric mechanism (that is - it is offset from centre - not that it is 'wierd'!) that can be continuously varied. By changing the offset, the cam can effectively be speeded up or slowed down, hence altering the duration for which the inlet valve is open (the duration of the outlet valves do not vary). This is completely different from the 'profile-switching' that you get in VTEC type systems, which do change from cams of one profile to another. I'm sure someone will correct me if I'm wrong though...
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