rogerguzzi Posted June 6 Share Posted June 6 Hello All Spitty has thrown another wobbly today!!! She ran good down to Plymouth yesterday and was ok for about 40/50miles today? But then suddenly started to run Very Weak and would not pull? We managed to get to a service area and I started tinkering? Fuel pressure is still good and no leads off that I can see and I have changed from ITB fuel load to Percent Baro and got it running ans I had turned the conntroller Authority from 12% down to 5%? Mayebe a mistake?) I have turned it back up to 10% Tomorrow when we are going across country I am going to try Autotune and see if I can get it better? I ould be the Lambda sensor faulty (I have another one in the can but it would be a pain in the arse to change!! So any thoughts on the problem?? Frustrated Roger and Worried Memsahib ps forgot to say we are at about 2500 to 3000 feet up?(it was as we went up it got worse??) pps I have now set the Baromertic Correction to 100 in both colums now Link to comment Share on other sites More sharing options...
zetecspit Posted June 6 Share Posted June 6 As you go up the fuelling would get rich (if no baro correction) I would be turning closed loop off to take the wideband out of the equation. If it is playing up, and you try autotune, it will be horrendous. Saying all that, if the wideband it showing weak, and teh car is showing symptoms, I would be checking other stuff. Is the TPS working OK? Link to comment Share on other sites More sharing options...
rogerguzzi Posted June 7 Author Share Posted June 7 Hello All TPS is showing 0 to 100% on the pedal full travel! Roger Link to comment Share on other sites More sharing options...
zetecspit Posted June 7 Share Posted June 7 3000ft reduces oxygen from about 21% to 18.6% ish. So you should be running "about"10% rich. Can you turn the baro correction off? (or is that what you have effectively done?) My thoughts are that it could be substantially over-compensating. Before we had baro on my efi, Gill was fudging fuelling on the 10CR by changing the injector size figure. That worked for us. She did it a few times on some highest passes. Link to comment Share on other sites More sharing options...
Nick Jones Posted June 7 Share Posted June 7 I’m not sure you are correct about it going rich at altitude Clive. That was my thought for many years. Then when I went to ITBs and was having variability issues, I wondered whether it was baro correction related. Did some reading and all that seemed to be say it goes lean at altitude due to reduced exhaust back pressure. Point being that you are measuring what goes in (though by inference not actual mass-flow) but not what goes out. https://www.msextra.com/forums/viewtopic.php?t=63844&start=80 Anyway….. given that it was fine (and has previously performed well under similar conditions) it sounds like there is a fault of some kind. You’ve checked TPS, do your baro and MAP sensors agree with the engine off? Take it the MAP sensor pipe is intact? (Though this coming off is more likely to make rich). It’s also possible that the O2 sensor is messing you up. Had this on the last European trip we did where it failed rich causing the ECU to pull fuel up to its maximum 5% allowance. So it was actually leaning, though reporting rich. In your case, are you reading the reported AFR from the dash display or from the ECU? And do the two agree? If the connection is lost between wideband and ECU, it may default rich, causing the ECU to pull fuel? Increasing controller authority will make matters worse in this case….. Good luck! Link to comment Share on other sites More sharing options...
JohnD Posted June 7 Share Posted June 7 (edited) Most Fuel injection runs off, to some extent, inlet pressure. which is least at throttles closed, max at WOT. So as atmospheric pressure falls, the system 'thinks' more fuel is required. More sophisticated systems include flow meters etc etc, but Lucas Pi uses only that parameter, and it goes very rich as you ascend - it's usually set a bit rich anyway as it tends to go lean at WOT. And atmospheric pressure varies a lot with height, as our 'popping' ears testify. Sea level is about 14.5psi (1000millibars) while at 3000metres, on the Col de Bonnette, the highest road pass in Europe , it's only 10psi (700mb) I've only gone that way once, and in a Pi fuelled car we only just made it. Lucas produced a height compensated metering unit, but they are hens teeth rare today. It's the bit on the bottom that does it. The oxygen content at height is the same as at sea level! 21% of the air is oxygen. But for chemical and physiological reactions it's the "partial pressure" that matters, and forgive me, but pressure is measured in "millimetres of mercury" as in a barometer for these purposes. 760mmHg at sea level, and 525mmHg at 3000m. The same percentage of Oxygen in that thinner air, but while that oxygen exerts 160mmHg at sea level, the partial pressure is only 110 at that height. If you climb even higher, as do extreme mountaineers, you may reach the Death Zone at 8000m where the partial pressure is less than 54mmHg which is insufficient for life. This is less of a problem for an engine, which compresses the air before reacting it with fuel. and much less for an engine with a supercharger or turbo, but yes, Clive, there is less oxygen in each gulp of air. But it's the way that a fuel injections system meters the fuel that makes it rich at altitude! John Edited June 7 by JohnD Link to comment Share on other sites More sharing options...
zetecspit Posted June 7 Share Posted June 7 2 hours ago, Nick Jones said: I’m not sure you are correct about it going rich at altitude Clive. That was my thought for many years. Then when I went to ITBs and was having variability issues, I wondered whether it was baro correction related. Did some reading and all that seemed to be say it goes lean at altitude due to reduced exhaust back pressure. Point being that you are measuring what goes in (though by inference not actual mass-flow) but not what goes out. https://www.msextra.com/forums/viewtopic.php?t=63844&start=80 Hmm, interesting thoughts. But PI cars choke up rich at altitude. So I am even more confused. Especially was we fudged our car by telling it we had bigger injectors (so lying to it, so it opened them for a shorter amount of time) Much to think about here! Link to comment Share on other sites More sharing options...
Nick Jones Posted June 7 Share Posted June 7 Yes. Cannot get my head around it. Especially since I had my previous tune (Single TB) on an earlier firmware version with the curve offsetting the opposite way and it seemed to work just fine. Currently have baro turned off…. Link to comment Share on other sites More sharing options...
rogerguzzi Posted June 7 Author Share Posted June 7 Hello All I have set the baro corretion to all 100 For some reason I had it set on dual wide band sensors ? I have altered it to single wide band. Controller authority is now 10% not 12% ! Primary fuel load in now Percent Baro and not ITB I richened up the VE table in a few places at 30 to 45 range? She is starting and running reasonable now but very rich on light throttle/loads 10.5 to 11.5 but if i work here harder it goes to the 13 to 15+ range She has not fouled the plugs but I think the economy has gone down the pan a quick check showed about 35mpg over about 170 miles but that was when running crap and today whih was about 110+ We are in Salamanca for 2 nights and she is in a garge so I may tweek the low VE table a bit and see what it is like on the next leg of about 100 miles? We can live with the extra fuel costs it just hurts my Pride after 45+mpg Plus she should not overheat on rih mixture been 30/32 degs here today Still seen 3 Castles couple of gateways and a Roman bridge! So getting better and just going to start on the Fizz Roger and the Happier and less worried Memsahib ps Why do we bother with these Old Cars??????? 1 Link to comment Share on other sites More sharing options...
mpbarrett Posted June 7 Share Posted June 7 Glad you have got it working ok. Good move to head south, we are at the north coast and it's cold and drizzling. Could do with a separate discussion about baro correction on EFI, my Herald ran very rich when we did the last 10CR over the high passes ( reminded me when I took the TR6 to the alps), so would like to sort it before this years. 10CR... Link to comment Share on other sites More sharing options...
Nick Jones Posted June 7 Share Posted June 7 Glad you are able to proceed Roger! Great pics as always. Link to comment Share on other sites More sharing options...
rogerguzzi Posted June 8 Author Share Posted June 8 Hello All I am going to put a bit of Baromertic correction back on (just the first four boxes as we will not be going higher I think?) Wish my luck!! Roger and the Memsahib ps 1st view from our balcony pps They were still sober at this stage!!! 1 Link to comment Share on other sites More sharing options...
JohnD Posted June 8 Share Posted June 8 This on-the-hoof engineering is as impressive as those magnificent castles and bridges! As to why do we bother? Just seeing yours next to said magnificent architecture says why! Enjoy! John Link to comment Share on other sites More sharing options...
rogerguzzi Posted June 9 Author Share Posted June 9 Hello All We are now in Hervas and seen 2 more castles and 2 mountain passes second one about 4,700feet!!! Spitty seems ok going up hills now and not to rich if pulling(12.5/13.5) but on very light throttle is still about 11/11.5 ? The Auto Correction does not seem to be working although set at 12%? (before I could see it changing at steady throttles?) The crane is different with a wooden main Spar? (the castle site was a quarry at one time) We filled up with fuel again and it works out at just over 35mpg but may get better on next fill after todays changes take effect? As you can see we are in another Doss House with rubbish view from the windows? Roger and the Memsahib ps we could see bugger all over the mountain passes as it was thick mist/fog!!!! 1 Link to comment Share on other sites More sharing options...
rogerguzzi Posted June 10 Author Share Posted June 10 Hello All I think I am going to turn the EGO sensor off as it seems a though it is still making it go rich? I can increase the throttle and it goes to 13/14 AFR but then it slowly richens it up to 10.5/11.5 Confused Roger Link to comment Share on other sites More sharing options...
rogerguzzi Posted June 11 Author Share Posted June 11 Hello All I am thinking the Lambda sensor is just making up numbers? I have worked the mpg out over the last 3 fill ups 419miles and 10.997galls = 38mpg!!! She seem to be going ok a few pops on overrun now and then but not getting hot and its been 24/25degs today! So I think I will leave it all alone now and sort it out when I get home? Nick is right I need to get the tables as close as I can then let the EGO tweak it a bit but She will still run ok without a working Lambda sensor! Now I am thinking if the tables are very close and you go up a mountain and it starts to go rich or lean and you give the EGO say 15% authority would that not then get it back to 14/14.7 ish?? Thoughts from Roger and the Memsahib just nods Link to comment Share on other sites More sharing options...
rogerguzzi Posted June 12 Author Share Posted June 12 Hello All Topped the tank up today and it works out at 37.6mpg over 496 miles I think I am going to turn the EGO back on but only 2% as it controls the tick over via the idle valve and she is dying often on slowing down! Plus I do not think that should affect the running to much? Roger Link to comment Share on other sites More sharing options...
thebrookster Posted June 13 Share Posted June 13 Do I presume that EGO is "Exhaust Gas Oxygen", otherwise known as Lambda sensor? Why not pop into a motor factors and grab a bottle of Cat cleaner? Wynn's does the stuff, designed to clean catalyst and O2 sensor (okay, you don't need the catalyst bit, just they tend to be coupled together). Then if there is any contamination on the sensor it should clean it off? For the sake of a few Euro's and the hassle of pouring a bottle into the fuel tank, worth a shot? Phil Link to comment Share on other sites More sharing options...
rogerguzzi Posted June 13 Author Share Posted June 13 Hello Phil Thats a thought I will have a look in the garage when next in one Roger Link to comment Share on other sites More sharing options...
Nick Jones Posted June 13 Share Posted June 13 Do you have any blowing at the exhaust manifold? Anywhere upstream or even immediately downstream of the sensor could affect the reading. Link to comment Share on other sites More sharing options...
rogerguzzi Posted June 13 Author Share Posted June 13 Hello Nick That maybe a problem as I had to remove the exhaust to get the gearbox out and I did not use the paste this time as it was a pain in the arse to get of but I do use proper clamps not ubolt type or jubeilee type proper wrap around type! What gets me is it was ok for 210miles UK then 50/60 Spain but went doolaly when got to about 2,500 feet?? She seem better today with the EGO back on and not dying on slow down so often? She seem to pull well and the next fill up we will see but 35/38mpg we can live with and do not want to try anything to much now she seem happyish until we are back in blightey then I have 3 weeks to sort it out before the Alpine trip!!! Roger and the Memsahib in Toledo and warm 30+ today!! ps breakfast view this morning Link to comment Share on other sites More sharing options...
rogerguzzi Posted June 18 Author Share Posted June 18 Hello All I have just worked out Spitty's mpg up to now 1145 and it is 37.57 mpg so not to bad after all? Plus she seems to be running fine (not taken plugs out to look !) and not over heating etc Roger Link to comment Share on other sites More sharing options...
rogerguzzi Posted June 19 Author Share Posted June 19 Hello All After the last fill up its still 37.5 mpg !! The AFR gauge is still showing rich a lot of the time but she seems to be running fine? Not touching any settings etc until we are home then I have about 3 weeks to sort it out before the Alpine Trip and the Stelvio(I must be Mad ???) Roger Link to comment Share on other sites More sharing options...
mpbarrett Posted June 21 Share Posted June 21 thats a good mileage. As you had the gearbox out before you went away I wonder if you have damaged the AFR sensor or wiring? mike Link to comment Share on other sites More sharing options...
rogerguzzi Posted June 21 Author Share Posted June 21 12 hours ago, mpbarrett said: thats a good mileage. As you had the gearbox out before you went away I wonder if you have damaged the AFR sensor or wiring? mike Hello Mike I was wondering that I will get up on the lift in the next few days and remove it and check it (I have another used one I can try to prove a point!) If it is I will bite the bullet and buy a new one!!!! Roger ps the total mileage is 1695 I will work out the mpg soon and still more photos to post 1 Link to comment Share on other sites More sharing options...
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