WAGON JON Posted July 25, 2011 Report Share Posted July 25, 2011 The 1980 200sx uses a 2.2 ohm resister next to the coil. Anyone know what it does? Also, will a Radio Shack 2.2 ohm resister work in the same way if it were used? Quote Link to comment
Hardwyre Posted July 25, 2011 Report Share Posted July 25, 2011 Can you take a picture of it? I'm seeing mentions of a ballast resistor, and if that's the case, it's going to be several watts worth of resistor, so RadioShack's little 1/4 and 1/2 watt resistors won't stand up to it. What type of ignition does the SX have in it? I thought ballast resistors were only used in points ignitions. If all it does is takes one of the coil terminals to ground, it might just be a noise suppression resistor instead. Quote Link to comment
ggzilla Posted July 25, 2011 Report Share Posted July 25, 2011 This is the 200SX dropping resistor, but it mounts under the battery. Quote Link to comment
jefe de jefes Posted July 25, 2011 Report Share Posted July 25, 2011 The 1980 200sx uses a 2.2 ohm resister next to the coil. Anyone know what it does? Also, will a Radio Shack 2.2 ohm resister work in the same way if it were used? I think it's for the tachometer like the one on the 720's. Is this what your talking about?? Quote Link to comment
Hardwyre Posted July 25, 2011 Report Share Posted July 25, 2011 2.2 kilo ohms. Big difference from 2.2. :P 1 watt.. Hmm. Okay, you can make do with something from Radioshack, but the question is why? That resistor should be fine unless it's damaged some how. What makes you believe it needs to be replaced? You can make a ~2.2k ohm 1 watt resistor out of the 5 pack of 2.2k 1/2 watt resistors: http://www.radioshack.com/product/index.jsp?productId=2062325 You're going to make a series-parallel array out of four of the resistors. _/---2.2k------2.2k---\______ \---2.2k------2.2k---/ Solder two of the resistors end to end making a 1/2watt 4.4k resistor. It's a good idea to shorten the center leads to make the overall package smaller. Do this twice. Now with your new 4.4k resistors, twist the lead end pairs together on each side. This will create an approximate 1watt, 2.2k ohm resistor pack. When using same value resistors: Soldering resistors in series (end to end) sums the resistance values of all the resistors in a series while keeping the wattage capacity the same. Soldering resistors in parallel (side by side) sums the wattage capacity while dividing the resistance value by the number of resistors. Quote Link to comment
HRH Posted July 25, 2011 Report Share Posted July 25, 2011 Yeah, the picture ggzilla posted is for the fuel injectors. It drops it from 12v to whatever minimal voltage the computer recognizes. Quote Link to comment
Sealik Posted July 25, 2011 Report Share Posted July 25, 2011 Yeah, the picture ggzilla posted is for the fuel injectors. It drops it from 12v to whatever minimal voltage the computer recognizes. I believe that drops the voltage to the injectors...in case of any low or increased voltage from batt/alt Maybe :D Mounted underneath the airbox.... on the 200sx Quote Link to comment
HRH Posted July 25, 2011 Report Share Posted July 25, 2011 It's for the amount of fuel as 12v to the injectors would be full open, if I remember correctly? Quote Link to comment
Sealik Posted July 26, 2011 Report Share Posted July 26, 2011 It's for the amount of fuel as 12v to the injectors would be full open, if I remember correctly? Found my manual... ..."protects the injectors from alternator surges and affects of other electrical components by lowering the source voltage." Guess my memory isn't too bad....... yet :) Quote Link to comment
WAGON JON Posted July 26, 2011 Author Report Share Posted July 26, 2011 I think it's for the tachometer like the one on the 720's. Is this what your talking about?? That is the one! Now, where or what models can procure one of those from? Truck, car, store, junk yard! Quote Link to comment
WAGON JON Posted July 26, 2011 Author Report Share Posted July 26, 2011 2.2 kilo ohms. Big difference from 2.2. :P 1 watt.. Hmm. Okay, you can make do with something from Radioshack, but the question is why? That resistor should be fine unless it's damaged some how. What makes you believe it needs to be replaced? You can make a ~2.2k ohm 1 watt resistor out of the 5 pack of 2.2k 1/2 watt resistors: http://www.radioshack.com/product/index.jsp?productId=2062325 You're going to make a series-parallel array out of four of the resistors. _/---2.2k------2.2k---\______ \---2.2k------2.2k---/ Solder two of the resistors end to end making a 1/2watt 4.4k resistor. It's a good idea to shorten the center leads to make the overall package smaller. Do this twice. Now with your new 4.4k resistors, twist the lead end pairs together on each side. This will create an approximate 1watt, 2.2k ohm resistor pack. When using same value resistors: Soldering resistors in series (end to end) sums the resistance values of all the resistors in a series while keeping the wattage capacity the same. Soldering resistors in parallel (side by side) sums the wattage capacity while dividing the resistance value by the number of resistors. I don't have one and I need it to continue with a 200sx to 510 EFI project I am doing. Thanks Hardwyre! Quote Link to comment
jefe de jefes Posted July 26, 2011 Report Share Posted July 26, 2011 That is the one! Now, where or what models can procure one of those from? Truck, car, store, junk yard! Junk yard. I have pulled them from 720 pickups. Quote Link to comment
Sealik Posted July 26, 2011 Report Share Posted July 26, 2011 I don't have one and I need it to continue with a 200sx to 510 EFI project I am doing. It only 'runs' the tac....so it won't interfere on the build/running of engine Quote Link to comment
Sealik Posted July 26, 2011 Report Share Posted July 26, 2011 You must be using the front (underhood) 200sx wiring? Quote Link to comment
WAGON JON Posted July 26, 2011 Author Report Share Posted July 26, 2011 You must be using the front (underhood) 200sx wiring? Yep. Gonna make it run some time soon. Quote Link to comment
WAGON JON Posted July 26, 2011 Author Report Share Posted July 26, 2011 The wire in the wiring diagram goes straight to the ecu. Does the tach run from an ecu signal? Quote Link to comment
Hardwyre Posted July 26, 2011 Report Share Posted July 26, 2011 I don't have one and I need it to continue with a 200sx to 510 EFI project I am doing. Thanks Hardwyre! I think I made sense. :) You got what I was getting at? With the tach, the values aren't horribly critical. Also, you'll want to probably put a couple layers of heat shrink tubing over the bundle to give it support. 2200 ohms on a 12-14 volt system is probably dropping it down around 5 volts which is what, I think, I lot of our tachs are triggered on. So ya, you don't really need the resistor right now to finish your engine, but it'll be nice for the sake of the tach. Quote Link to comment
WAGON JON Posted July 26, 2011 Author Report Share Posted July 26, 2011 I think I made sense. :) You got what I was getting at? With the tach, the values aren't horribly critical. Also, you'll want to probably put a couple layers of heat shrink tubing over the bundle to give it support. 2200 ohms on a 12-14 volt system is probably dropping it down around 5 volts which is what, I think, I lot of our tachs are triggered on. So ya, you don't really need the resistor right now to finish your engine, but it'll be nice for the sake of the tach. Gotcha, it makes sense! Quote Link to comment
Sealik Posted July 26, 2011 Report Share Posted July 26, 2011 I wired all this (mess :blink: ) into my 720 Z24 wiring. No tach resistor included 'Basically' just needed 3 wires hooked to power Ongoing project........... :D Quote Link to comment
brodster Posted July 26, 2011 Report Share Posted July 26, 2011 Jon you have this right: http://dimequarterly.tierranet.com/dq/dq_1_1.pdf. The 200sx manual is better but this is a good quick reference. I would have to trace back where the tach actually goes, but my first thought is that the 2.2k resistor helps protect the ECU. From the wiring diagrams I have seen, that is the input for the ECU where it measures engine speed (which may or may not have anything to do with the tach). Though I have never measured it, there very large pulses that come off the negative terminal of the coil (from what I have read over 100V). If I was designing something to interface with that, I would use something to drop the voltage to usable and safe levels for digital equipment....probably in the 5V range. Again, I have not verified the actual hookup and where everything goes, but until different information surfaces, I would NOT run your engine without sometype of 2.2k resistor there. Although the Haynes manual says differently, the dropping resistors are typically used to match ECUs to low impedance injectors. Basically, one end of the injector is hooked up to positive, and the ECU sinks all that current to ground everytime it triggers the injectors. Because of the lower impedance of the injectors, WAY to much current is sunk through the system. I would image overheating injectors and fried ECUs. Quote Link to comment
brodster Posted July 26, 2011 Report Share Posted July 26, 2011 Oh and a 2.2k 1W resistor from Radio Shack should do the trick. Like someone posted above, you can mix and match values to get the desired values. <BR><BR>It probably isn't critical in this application but there are MANY types of resistors with different properties and tolerances. Most of the time it doesn't matter, but you can get into some areas where the wrong resistor will cause problems. Since I am in the beginning stages of doing a similar upgrade, I will try to figure it out. Quote Link to comment
datzenmike Posted July 26, 2011 Report Share Posted July 26, 2011 The 720 carb engines with tach option has the resistor so it's not ECU related. Quote Link to comment
brodster Posted July 26, 2011 Report Share Posted July 26, 2011 The 720 carb engines with tach option has the resistor so it's not ECU related. Carburetors don't use an ECU? ;) Sorry, I was solely responding to the 1980 200sx setup. Quote Link to comment
Sealik Posted July 26, 2011 Report Share Posted July 26, 2011 It only 'runs' the tac....so it won't interfere on the build/running of engine Wrong.... The 200sx wiring had 1 wire that I spliced into the B/L feeding the 2.2ohm tack resistor. Will not run when removed Quote Link to comment
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