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jad

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Posts posted by jad

    Lexus 109 “Koya”

    in Modified Vehicle Builds & Special Projects

    Posted

    Looks like the easiest thing to do it treat it as non pwm as with petrol high impedance injectors as below. Please correct me if I am wrong!

     

    Injector Resistors

    However, instead of the flyback board, you may choose to use resistors in series with your injectors.

    Several people reported that resistors do NOT result in significantly longer opening times, or any other troublesome effects, so this is a good solution for many installs. To eliminate PWM altogether, use a 5 to 8 ohm resistor (with a 20 to 25 watt rating) in series with each injector.

    If you want to avoid using PWM with your low-impedance injectors, you can use ballast resistors in series with the injectors. You should use one resistor (20-25 Watts) in series with each injector, otherwise the injectors may not all draw the same current, and the failure modes become complicated and difficult to diagnose. As well, you would need a very large resistor to handle more injectors. For example, if you allowed 2 Amps through four 1.2 Ohm injectors wired in parallel (0.3 Ohms total) to one 7 Ohm resistor, the power dissipated would be:

     

    P = V * I = 12.5 Volts * 2 amps x 4 injectors = 100 Watts!

    If you use resistors that limit injector current to less than 2 amps, you can disable the PWM mode (by setting PWM% to 100%, and time threshold to 25.4msec) and treat the system as high-impedance. To limit the current to under 2 amps, you need:

    resistor ohms = (alternator voltage / 2.0 amps) - injector resistance

    For example:

    resistor ohms = (14.0 volts / 2.0 amps) - 1.2 ohms

    => resistor ohms = 7.0 - 1.2 = 5.8 ohms

    You can also use the calculator below. Enter your injector resistance in ohms, your hold current in amps, as well as your injector impedance in ohms, in the form below and press the "Compute resistor" button.

    Lexus 109 “Koya”

    in Modified Vehicle Builds & Special Projects

    Posted

    There is soooo much information i do not know how people remember it all! I found the below. If you follow the injectors and fuel supply link it takes you here http://www.megamanual.com/v22manual/minj.htm which looks like a very helpful page if I could understand it 😂

    To tune the PWM [pulse width modulation] values for your engine, you need to know what kind of injectors you have- low impedance or high-impedance. If you are running high-impedance injectors (greater than 10 Ohms), then set the PWM time to a number like 25.4, in essence you are disabling the PWM mode. This allows full voltage to the injectors throughout the pulse width.

    For low-impedance injectors (less than 3 Ohms), you need to limit the current to avoid overheating the injectors. To do this, there is a period of time that you apply full battery voltage [peak] current, then switch over to a lower current-averaged [hold] current, i.e. peak and hold. Alternatively, you can add resistors in series with the injectors. See the Injectors and Fuel Supply section of the MegaSquirt® manual for more details.

    To run low-impedance injectors with the PWM current limit mode, you need to set two parameters - the "PWM Current Limit %" and the "Time Threshold for PWM Mode" - both are on the “Constants†page. The current limit % is the percent duty cycle when the current limit is invoked. The time threshold is the amount of time from when the injector is first opened until the current limit is activated.

    High impedance injectors can run on 12 Volts without problems. Low-impedance injectors require some form of current limiting. MegaSquirt® has pulse width modulation to limit the current. You need to set the PWM parameters to match your injectors:

    Lexus 109 “Koya”

    in Modified Vehicle Builds & Special Projects

    Posted

    That's interesting to hear! Thanks.

    I have been told the following by an LPG retailer. Does it sound correct or not? Wouldn't this mean it is not possible to control the LPG injectors with MS?

    "all LPG injectors need special driver - they are driven using pick and hold current driver - so unlike petrol injectors they cannot be opened by applying voltage to the connectors. The PWM 10kHz with current limiting is needed in order to not overheat the coils. There are some injectors with relatively high impedance like Matrix but still - the current needs to be controlled in order to not damage the plunger seasl and to protect the coils."

    Cheers

    jad

    Lexus 109 “Koya”

    in Modified Vehicle Builds & Special Projects

    Posted

    Thanks Bowie,

    The 1uz does have high impedance injectors as well annoyingly. Although there are "upgrades" that are low impedance so potentially changing them so that both LPG and petrol injectors are the same could be a route forward. Although potentially a more expensive way.

    The engine on the open road tends to run in the 70-80 degree range (Seams a bit low stat is meant to be 82). It is only when going slow on lanes/idling that the temp goes up until the fan cuts in at 95ish.

    Those boards looks like an interesting addition to MS and not very expensive. I am running MS2 are they still compatible? Although it sounds like it might be easier to just put resistors in the injector wiring? How big are we talking Elbekko?

    Cheers

    Jad

    Lexus 109 “Koya”

    in Modified Vehicle Builds & Special Projects

    Posted

    Haha, I still dont drive it enough! I started cycling to work :blink: so my millage has been reduced somewhat and as I have 3 cars. Its hard to give them all the correct amount of love.... Although I am currently planning to sell my economical car (soon) the only volvo 740 manual diesel turbo sun roof model on the roads in the UK :-o (obviously worth a mint) and lpg the landy so it is a little more economical on long runs, and I am soon planning to put the TVR in my garage to rebuild it but as there is a kitchen occupying it till ~mid January that has been delayed somewhat! So I will be left with my winter and summer cars but both V8's :D

    Has anyone got any good articles on LPG'ing a landy with megasquirt? I am trying to see if I can do it without the LPG ECU to reduce cost and size of the components being installed. With switchable maps in MS it shouldnt be too hard to switch over from petrol to lpg components?.... I havent found anyone that has done it and written it up yet :(

    As for a turbo.... yes It would be pretty awesome/very possible and completely ridiculous to go and double the Hp and Torque with a turbo.... However then i would be committed to uprating everything in the driveline now! If/when things break. I will only replace with uprated components so the car will go in the direction of being able to have more power at some point.... but thats a long way off! Steering, braking and suspension may have to be enhanced as well!

    When you say outer spring do you mean the top spring? I am a bit surprised as they are the original springs as far as I am aware. Would have thought they would have been made to a reasonable standard back then.... I will try and turning it around and then find something to go and drive onto :i-m_so_happy:

    Thanks Soren

    Jad

    Lexus 109 “Koya”

    in Modified Vehicle Builds & Special Projects

    Posted

    Afternoon,

     

    Has been a long time since I have updated this. Not huge amount has changed but I did go laning in Wales this weekend! This happens far too infrequently <_<

    Fitted some new tyres before we went. Glad I did as on the old ones I would have had to be dragged through a lot of lanes! However as it was I only got stuck once due to the leaf spring plates.

    tyres.thumb.JPG.2165c9638b56440c352109e12a0de7ae.JPG

    Tested out the articulation and was quite impressed for what really is almost standard suspension.

    5a12c71b8d587_Art1.thumb.JPG.345940c34888c23c2da974cb9dc31268.JPG

    5a12c71ca4cf2_Art2.JPG.588d39fec03b0c7b220cf6d15c6f8a15.JPG

    We also did a bit of wading proving that the engine runs well when soaked in water ;) Although modifications were made before attempting some of the deeper sections....

    Snorkel.thumb.JPG.a6a1f89a602731759389cb26c1917769.JPG

    Only had one breakage over the weekend which was the windscreen wiper blade spring :blink: When scraping the screen Sunday morning it was a tad on the rusty side so just pinged into 2 parts when asked to move!

    I have been having an issue with the engine stalling and immediately restarting for quite a long time. It has been hard to investigate anything as it was largely intermittent sometimes not occurring for weeks and then repeatably happening over and over again :angry: It was having quite the hissy fit this saturday and sunday morning so I decided to prod around. I didnt find anything in particular but disconnecting and reconnecting the EDIS8 appears to have stopped it so am hoping it was just a dodgy connection on that :i-m_so_happy:

    Am also having a problem with one of the leaf springs. As in the picture below it is fouling on the chassis creating quite the rattle!

    5a12c71fb9154_SpringFoul.JPG.3a7608c2198b161e1fd5d4f16751b0b8.JPG

    5a12c71e90462_Springclearright.JPG.bb12fd09edfb3ec3ae3925ea3c9619a1.JPG

    I have tried moving the spring over by loosening the U-bolts ratcheting the spring over and then torquing the U-bolts but after a short drive it starts to move over and make contact again! Anyone think of any potential solutions?

    ratchet.JPG.d6a2daf7a823d00bfeea8d2a8c0e6475.JPG

    Thanks

    Jad

    Lambda sensor ERR6729 alternatives and megasquirt

    in International Forum

    Posted

    Interesting,

    I have already ordered 2 original ntk sensors but you have got me thinking. The original sensors are 3 wire titanic narrow band sensors. They probably operate 0-1V. The normal output for the LC2 is 0-5V but as bowie says the outputs are programmable. My question is now can you program the lc2 to mimic a narrow band sensor swinging from 14-15AFR over 0-1V? Does anyone have a controller that they could try this with? Having looked at the instructions for the LC2 it looks like there is potential. Although if you did that and it measures an AFR of 20 then is it going to try and output 5V or more?....

    Screenshot_20170604-092217.thumb.png.547b81fc37a23ad573af1e538876dd8c.png

    Lambda sensor ERR6729 alternatives and megasquirt

    in International Forum

    Posted

    Afternoon,

    I need to replace the lambda sensors in my tvr chimaera 400 as it's emissions are a little off.... I am planning on rebuilding a 4.6 which I want to put in next year with megasquirt. Does anyone know if these lambda sensors are compatible with the standard setup and megasquirt? Is there an alternative sensir i am better off with or will i just have to bit the bullet and buy more sensors come megasquirt?

    Dare I ask are britpart lambda sensors reliable or do I just go straight for ntk? Any other makes worth considering?

    Thanks for your help

    Jad

    4.6 rockers/push rods etc what do i have?

    in International Forum

    Posted

    Because tvr not land rover. I think I'm talking to the wrong set of people. I always used to get lots of helpful answers on here. It would be nice if people said well you can do this and this but it will cost this and let the person asking make their own mind up. People do things because they want to. No it doesn't always make sense to everyone else but it makes them happy. Maybe I'm just getting cynical now I'm in the over 30 club....

    Jad

    4.6 rockers/push rods etc what do i have?

    in International Forum

    Posted

    Thanks guys. You learn something new everyday! Do older engines have adjustable rockers or am i just thinking of the 200tdi that i used to have?

    I am going to be building the engine for my tvr so would like it to rev more.... Anyone know any ways of accomplishing this? I can find much on internet...

     

    Thanks

    Thanks

    Series 3 front Propshaft picture

    in Series Forum

    Posted

    Can anyone help me. would like a picture of a standard vehicles front Propshaft sliding joint. I think mine is bottoming out under heavier breaking. I have a spacer in my very non standard car but am not sure if I should get a spacer 5 or 10mm thinner. this is a picture of mine.

    Thanks

    Jad

    IMG_20161030_152704409-768x1365.jpg

    Forum relay Leamington or Langford, Beds to Newbury 4x4

    in International Forum

    Posted

    Evening everyone,

    I have sold a diff to Nige and am currently struggling to get it to him. Anyone going from either leamington area or Langford in Bedfordshire to old Sodbury sort out on Sunday 2nd October that could take it down to him? The diff is currently near leamington but I am heading over to Langford on Friday 30th so could take it over that way then.

    I am out of the country over the next few days but could deliver the diff to anyone near leam on Thursday night.

    Thanks you for your help,

    Jad

    Lexus 109 “Koya”

    in Modified Vehicle Builds & Special Projects

    Posted

    Evening.

    Not a great amount has happened my vehicle recently. I have had to grind a bit out of the engine adapter as it was contacting the propshaft.... need to wait and see if I have taken enough out now. I also have my second mot tomorrow! It expired on sunday... not reminder for the garage :-S

    I also have entered the LRO modified vehicle of the year competition. So if anyone would like to vote for me (3 times as you are allowed to vote that many for some reason...) you can do so here

    http://www.modifiedlro.co.uk/

    Not the best photo. Wings have since been painted and the description could have been filled out a bit more but I was busy at the time! Should also have included a link to all my photos but I'm not allowed to change it anymore :-/

    Thanks

    Jad

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