more After market EFI instal questions
  • Help
Results 1 to 11 of 11
  1. #1
    1000+ Posts jo proffi's Avatar
    Join Date
    May 2003
    Location
    sydney
    Posts
    8,496

    Default more After market EFI instal questions

    Idle valve.

    The car has a ford 2 wire valve, which is all wrong, not least of which because it says ford on it.
    The ECU has a single PWM send from an aux out.

    Advertisement


    I have a few 3 wire bosh valves, and am keen to use one of them.
    I have found out enough from my reading to see that the three wire valve uses a common + and switches earth to the push or pull side of the valve to get the correct setting.

    I have also read that a resister can be put between the shut - and earth to keep the thing shut, and the single PWM feed from the ECU can be wired to the open side to pull against this.

    Has any one had any experience with this type of mod or do i need to suck it and see???

    I notice MS (glen's garage) has a 3 wire valve driver for their boards. I wonder how generic this is??

    Jo

  2. #2
    1000+ Posts jo proffi's Avatar
    Join Date
    May 2003
    Location
    sydney
    Posts
    8,496

    Default

    So off to jaycar i trotted to buy a 35-40 ohm 50w resister.
    I now know that this is far bigger than anything jaycar sell.

    Damn, I'm not going to get this sorted in any type of hurry.

    Same as everything else, it seems.

    Jo

  3. #3
    1000+ Posts robmac's Avatar
    Join Date
    Nov 2004
    Location
    Melbourne / Caulfield
    Posts
    19,466

    Default

    Quote Originally Posted by jo proffi View Post
    So off to jaycar i trotted to buy a 35-40 ohm 50w resister.
    I now know that this is far bigger than anything jaycar sell.

    Damn, I'm not going to get this sorted in any type of hurry.

    Same as everything else, it seems.

    Jo
    Jo,

    I'm curious WTF you would need such a big resistor, or why you need the resistor anyway.

    14 volts (worst case voltage) applied across 35 ohm (Power = V SQUARED/R)
    is a power of 196/35 = 5.6 watts

    So if it's connected in series with something then the power must be lower that 5.6 watts.

    I think their is magnitude of 10 error in someones calcs

  4. #4
    Banned
    Join Date
    Nov 2004
    Location
    sydney, australia
    Posts
    11,301

    Default

    just as well he had the 4wd to get it home..

  5. #5
    1000+ Posts jo proffi's Avatar
    Join Date
    May 2003
    Location
    sydney
    Posts
    8,496

    Default

    Quote Originally Posted by robmac View Post
    Jo,

    I'm curious WTF you would need such a big resistor, or why you need the resistor anyway.
    I realy dont know much about electrics, Rob, but I think it is to wire up a motor that is designed for a pulsed signal to be wired up hard to the 12v.

    Its already getting to be too much hassle after one wasted trip to jaycar and it's probably just better to go out to pick apart and find a two wire idle valve with a hard return.
    Jo

  6. #6
    1000+ Posts robmac's Avatar
    Join Date
    Nov 2004
    Location
    Melbourne / Caulfield
    Posts
    19,466

    Default

    Quote Originally Posted by jo proffi View Post
    I realy dont know much about electrics, Rob, but I think it is to wire up a motor that is designed for a pulsed signal to be wired up hard to the 12v.

    Its already getting to be too much hassle after one wasted trip to jaycar and it's probably just better to go out to pick apart and find a two wire idle valve with a hard return.
    Jo
    In a nutshell you don't have enough voltage to generate 60w from that resistance.

    You source of information is unreliable.

    As a gentle hint, there is no time like the present to bone up on basic electricity. You will find fault finding a lot easier.

  7. #7
    Banned
    Join Date
    Nov 2004
    Location
    sydney, australia
    Posts
    11,301

    Default

    i have in all seriousness found that having a car non funtional because i have committed to some course of 'improvement' is a bloody good encouragement to boning up on the things necessary to get it running!

    great project, jo, and nothing like biting off more than a comfortably mouthful

  8. #8
    1000+ Posts schlitzaugen's Avatar
    Join Date
    Nov 2010
    Location
    loneliness capital of the world
    Posts
    9,414

    Default

    Quote Originally Posted by jo proffi View Post
    I realy dont know much about electrics, Rob, but I think it is to wire up a motor that is designed for a pulsed signal to be wired up hard to the 12v.

    Its already getting to be too much hassle after one wasted trip to jaycar and it's probably just better to go out to pick apart and find a two wire idle valve with a hard return.
    Jo
    Jo, what Rob is saying is that for the voltage drop yo have over the resistor, a certain current will be drawn (Ohm's law), which in turn means that a certain power will have to be dissipated as heat. This power is easily calculated as it is the product of the voltage and the current (expressed in volts and amperes respectively the result will be power in watts, don't ever forget correct measuring units). Rob has calculated exactly this for you and he is right.

    Now just so you know, resistors come on the market in a number of wattage ratings (this rates the power they are capable of dissipating without burning). A 50Watt resistor like you calculated would have been found in the tube control circuitry of old TV sets (cathode tubes), I think in the vertical scanning unit. If you find one lying on the side of the road, smash it and have a look near the tube terminals, you might just get lucky. They look like a white square section sausage about 10cm long and are made of a ceramic material (they're brittle but not that fragile). Might be round too. For a 5W resistor, I think you would have to look around the power source of a 70s TV set, maybe B/W, not sure colour TV had the same power sources. Jump on the 'net and you should find anything you need. You can try locally (in Sydney, you lucky barstard) Farnell electronics or RS components, they might have what you need on the shelf. They sure have catalogues on the net.

    http://www.farnell.com/

    http://australia.rs-online.com/web/?...ponents_Phrase

    Heres' what I found:

    http://australia.rs-online.com/web/p...power/1073380/

    Really nice with its own heatsink and mounting baseplate.
    ACHTUNG ALLES LOOKENPEEPERS

    Das computermachine is nicht fur gefingerpoken und mittengrabben. Ist easy schnappen der springenwerk, blowenfusen und poppencorken mit spitssparken. Ist nicht fur gewerken bei das dummkopfen. Das rubbernecken sightseeren keepen hands in das pockets-relaxen und watch das blinkenlights.

  9. #9
    1000+ Posts robmac's Avatar
    Join Date
    Nov 2004
    Location
    Melbourne / Caulfield
    Posts
    19,466

    Default

    Quote Originally Posted by jo proffi View Post
    I realy dont know much about electrics, Rob, but I think it is to wire up a motor that is designed for a pulsed signal to be wired up hard to the 12v.

    Its already getting to be too much hassle after one wasted trip to jaycar and it's probably just better to go out to pick apart and find a two wire idle valve with a hard return.
    Jo
    The only way you can make it work is to program the ECU to "pulse" the output.
    No resistor will will make a sink or source output create a pulse train.
    Pulsing is a function of the ECU switching the output.

  10. #10
    1000+ Posts PeterT's Avatar
    Join Date
    Jul 2000
    Location
    Castle Hill, Sydney
    Posts
    7,567

    Default

    I also have a Ford 2 wire stepper motor that was run from an SMC via PWM. I can give you the settings for that but can't offer any other help. I've found PWM idle stepper motors to be a pain in the @rse. Only the four wire motors give accurate and fast respone times, which your SMC doesn't support.

    '92 205 Mi16
    '90 Mi16x4

  11. #11
    Administrator
    mistareno's Avatar
    Join Date
    Nov 2002
    Location
    Melbourne
    Posts
    4,926

    Default

    If the ecu is putting out a PWM, why not use a boost control valve to control idle speed?

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •