mobythevan Posted April 28, 2009 Share Posted April 28, 2009 Or power used for pullup is only on during run and not cranking? Quote Link to comment Share on other sites More sharing options...
gumby240 Posted April 29, 2009 Author Share Posted April 29, 2009 Allright i will check all that, thanks again for everyones help Quote Link to comment Share on other sites More sharing options...
gumby240 Posted April 30, 2009 Author Share Posted April 30, 2009 Hey i am not sure i used the right resister when i wired the dizzy, i used a 1/4 watt 1k resister. Also can you explain the pullup? Quote Link to comment Share on other sites More sharing options...
softopz Posted April 30, 2009 Share Posted April 30, 2009 I think your right there check your jumpers on the board Quote Link to comment Share on other sites More sharing options...
gumby240 Posted April 30, 2009 Author Share Posted April 30, 2009 I have not taken that apart it was a preassembled unit from ms & it was supposed to be already set up. BTW is there different types of resisters i am still trying to understand the pullup thing you guys are talking about ? Quote Link to comment Share on other sites More sharing options...
mobythevan Posted April 30, 2009 Share Posted April 30, 2009 Here is the text from the sticky about pullups, you will be fine using a 1/4 watt resistor. It needs to be attached to the correct wire fromthe dizzy and then to a 12 volt source that has power during cranking and running. *Pullup/Pulldown resistor quick course You use a pullup resistor to get your line(or pin,connection) to some voltage (5,12, etc). Suppose you want a pin to have 5volts. If you just add a wire to 5 volts there is nothing to limit the current and if the pin happens to be an input to a transistor that is switched to ground then you have a short to ground from 5 volts and you burn stuff up. So instead you add a resistor to the 5 volts and the resistor will limit the current according to ohms law. Current is voltage divided by resistance. If you put a 1k ohm resistor to 5 volts then if the pin is switch to ground by internal electronics it can only draw 5 milliamps max(the resistor current-limits the path). A pulldown is similar except that you want a pin/wire connected to ground and you want the path to be current limited. To size the pullup or pulldown correctly you should know what the circuit is that you are adding the resistor to. But as a general rule you can use a 1k resistor for 5volts and a 2k resistor for 12volts. That limits the current to a few milliamps which is conservative. Sometimes the circuit may require more current to operate properly. For the pullup resistors I am just using 1/4 watt resistors. I=E/R I=12v/1k I=.012 or 12 milliamps P=I*E P=.012*12v P=.144watts little over 1/8 watt I=current E=voltage P=power R=resistance Quote Link to comment Share on other sites More sharing options...
gumby240 Posted April 30, 2009 Author Share Posted April 30, 2009 Ok so I have power coming to the resister but nothing on the other side (when using a test light) I am asssuming the test light would just be dim if all was working correctly. Is it possible to put the resistor in backwords or is something else going on? Quote Link to comment Share on other sites More sharing options...
mobythevan Posted April 30, 2009 Share Posted April 30, 2009 With the test light on the dizzy wire side of the resistor, spin the dizzy slowly by hand and you should see the light turn on and off as the slots in the dizzy pass through the optical encoder. Quote Link to comment Share on other sites More sharing options...
gumby240 Posted April 30, 2009 Author Share Posted April 30, 2009 I just untaped my harness to the dizzy & found a loose wire so i hope that is the problem. Quote Link to comment Share on other sites More sharing options...
gumby240 Posted April 30, 2009 Author Share Posted April 30, 2009 Nope still no power on the other side of the resistor. Is it possible the resistor is bad? Quote Link to comment Share on other sites More sharing options...
dexter72 Posted April 30, 2009 Share Posted April 30, 2009 You stated previously you were not sure of the status of the turbo dist you are using. So check all your wiring again and then check the dist. In my opinion you should be able to turn the key to on and the fuel pump relay should click. If that is not happening and you have no power to your pump, you may have wired the relay up incorrectly. The relay is bad or your connections are not good. So re-check everything even if you have done it 10 times before. Quote Link to comment Share on other sites More sharing options...
gumby240 Posted April 30, 2009 Author Share Posted April 30, 2009 Ok i will try that. I also went ahead & replaced the resistor just in case & now i have power on the other side but still no rpm in megatune. Quote Link to comment Share on other sites More sharing options...
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