Fly Posted June 3, 2013 Author Share Posted June 3, 2013 Hi guys. Right I've been racking my brains into the missfire/running lean. One idea I came up with was not giving the 7m jets enough amps. So the stock 330s with no resistor pack are 13.8 ohm resistance, assuming a 13.5v system (engine running) that gives a current to the jets of 0.98 amps. So I have replaced them with my 440s from the 7m and wired inline a 10ohm 50w resistor, the jets resistance is 2.8 ohm so 12.8 total resistance. This when worked with a 13.5 v system gives an amp value of 1.05. Stay with me. Right so what I'm wondering is if I am restricting the amps too much...what I really need is the minimum amp value for the injector to function correctly I can then work this through to check my resistance value is correct. I have used the part number to search but I'm not coming up with any minimum value. So anyone running these jets can you let me know what resister you are using or if you have the info the minimum amp value to run the jet. Thank you . Quote Link to comment Share on other sites More sharing options...
David P Posted June 3, 2013 Share Posted June 3, 2013 (edited) These links might help. http://www.mkivsupra.net/vbb/showthread.php?280719-Injector-resistor-pack&highlight=resistors http://www.internetwork.org.uk/mechanical/Injectors/Injectors.htm I used these. http://www.mkivsupra.net/vbb/showthread.php?233707-Project-Supracharger&p=3474594&viewfull=1#post3474594 Edited June 3, 2013 by David P (see edit history) Quote Link to comment Share on other sites More sharing options...
Fly Posted June 3, 2013 Author Share Posted June 3, 2013 Cheers David. Wow all the info I had pointed towards 10ohm resistors. Looks like I'm ordering some 5ohms then Quote Link to comment Share on other sites More sharing options...
Fly Posted June 3, 2013 Author Share Posted June 3, 2013 David I take it your running the stock he ecu? Do you know what the draw limit is on it? I'm guessing its over 1.6 amps as your running less resistance than me Quote Link to comment Share on other sites More sharing options...
David P Posted June 3, 2013 Share Posted June 3, 2013 I'm running an AEM series 1. The resistors I used were as recommended by heckler. http://www.mkivsupra.net/vbb/showthread.php?266042-Resistors-Required-for-Injectors&highlight=resistors+resistor+pack Fill yer boots. http://www.ebay.co.uk/sch/i.html?_trksid=p5197.m570.l1313.TR0.TRC0&_nkw=6.8ohm+50w+resistors&_sacat=0&_from=R40 Quote Link to comment Share on other sites More sharing options...
Fly Posted June 3, 2013 Author Share Posted June 3, 2013 Cheers David. I have ordered some 5ohm resistors so will give me 7.8 ohms total per chan Quote Link to comment Share on other sites More sharing options...
Noz Posted June 4, 2013 Share Posted June 4, 2013 Maybe do some research to how the resistance effects the injector duty cycle. May be a no brainer. Have you tried my coil yet. Quote Link to comment Share on other sites More sharing options...
Fly Posted June 4, 2013 Author Share Posted June 4, 2013 Noz had a look buit there is alot of varying info out there hence why i started with 10ohm resistors. What would be ideal is to find out what the minimum amp value is to fire the injector then i can work out a resistance based on that. Have tried the coil yet should get to fit it tomorrow evening as im in late tonight. Quote Link to comment Share on other sites More sharing options...
Noz Posted June 4, 2013 Share Posted June 4, 2013 The current isn't something you should be worrying about. The voltage fed from the ECU will be the same, injector regardless. If you change the resistance to the correct value you will get the correct current. I understand your trying to match the correct current, but if you just replace the new setup with the old resistance the values will be the same. I've never seen any reference to the current for the injectors. Usually people just correct the resistance to allowing the voltage and current to also be correct. I would say replace the 10ohm's for 6.8 as heckler recommended. I know I didn't use ten when I done mine. Apart from changing the coil, I would look into swapping the resistance to the same as the resistor packs. Quote Link to comment Share on other sites More sharing options...
Fly Posted June 4, 2013 Author Share Posted June 4, 2013 the reason im worried about current is due to the heat thats produced and the draw put on the ecu which i do not want to fry i read 1.2-1.6 amp draw is about the limit though again this could be wrong, you are correct the voltage will be the same but by dropping the resistance to the correct ammount (whatever that is) i increase the current and therefore draw/heat. i dont think i understand what you mean by replace the new setup with the old resistance? do you mean just attach the 440s into the same circuit the 330s were in? if so that would mean a current of about 3-4 amps which is way too high, but like i said i think im missunderstanding what you mean there. Im going to run in the 5ohm resistors with the 2.8 ohms already in the jets. According to the above topics and threads anything above 6 is ok but below 8 is better. Quote Link to comment Share on other sites More sharing options...
Noz Posted June 4, 2013 Share Posted June 4, 2013 Lol this is getting very confusing when it doesn't have to be. Don't worry about the current. Worry about the resistance. Get the new setup to run the same resistance as the old one. Change the resisters to 6.8 instead of 10. Quote Link to comment Share on other sites More sharing options...
Fly Posted June 4, 2013 Author Share Posted June 4, 2013 my head hurts.... right ile send back the 5ohm ones and order some 6.8s just for simplicity as i dont want to kill the ecu unless anyone can tell me otherwise. Quote Link to comment Share on other sites More sharing options...
David P Posted June 4, 2013 Share Posted June 4, 2013 (edited) Use 6.8's and gap the plugs @ 20 thou, then Bob should be your Auntie and your Driving Licence may be worried. Edited June 4, 2013 by David P (see edit history) Quote Link to comment Share on other sites More sharing options...
Fly Posted June 4, 2013 Author Share Posted June 4, 2013 thanks for sticking with me guys. Gaps done, resistors ordered, will be here tomorrow. Quote Link to comment Share on other sites More sharing options...
Noz Posted June 4, 2013 Share Posted June 4, 2013 Dude we're here to help We could all be wrong and you could fry your ECU lol jokes As me and David both know, asking for help puts you in a state of panic. Luckily theres lots of people on this forum prepared to help, sadly I'm not one of them that's any good at it hahahhaha Quote Link to comment Share on other sites More sharing options...
Fly Posted June 7, 2013 Author Share Posted June 7, 2013 Hi guys. Escaped work early and thought the weather was nice enough to attack the supra before pub o clock. Fitted cleaned 440 injectors and required the resistors so now they are 6.8ohminstead of 10ohm. Still same issue of 3500 rpm warning light and sounds like she's spitting. Fitted noz's ignition coil....better but still the same Fitted noz's ignitor.......still the same Haven't tried the leads yet. Needles to say I'm quite annoyed. One clue though maybe. I fitted a fuel pressure gauge and tapped into the fuel line that runs to the pressure regulator so the left line that attaches to the fuel rail as you look at it square on. Fired her up...gauge reads zero Took her out and loaded her up gauge doesn't move from zero. So one of three things maybe.....the gauge is broken, the fuel pump is broken or I haven't tapped the correct fuel line Old pump going in to confirm this. Quote Link to comment Share on other sites More sharing options...
Noz Posted June 8, 2013 Share Posted June 8, 2013 I think swap back to old injectors. Please get back to me about those bits mate! Quote Link to comment Share on other sites More sharing options...
David P Posted June 8, 2013 Share Posted June 8, 2013 If there's no fuel pressure, it won't matter what injectors are in there. Quote Link to comment Share on other sites More sharing options...
Fly Posted June 9, 2013 Author Share Posted June 9, 2013 Noz, replied bits will be with you Tuesday at the latest. David thanks for getting back to me. Replaced the leads today, the last of noz's parts. Still the same issue. Replaced the fuel pump to the stock one...still showing 0 on my pressure gauge, the gauge did move to slightly above 0 on start but then dropped back down. I removed the gauge whilst the car was running and the fuel just trickles out slowly I would assume that the fuel pressure should be a lot higher than this? I am at a bit of a loss now. Help!? Quote Link to comment Share on other sites More sharing options...
ashbuster Posted June 9, 2013 Share Posted June 9, 2013 do you have an aftermarket fpr or are you using the stock one? maybe its buggered? Quote Link to comment Share on other sites More sharing options...
Rich.2211 Posted June 9, 2013 Share Posted June 9, 2013 I'm not clued up on the fueling system but you haven't got some dirt etc. in there whilst changing the fuel filter or anything which is obstructing the fuel flow have you? Absolute stab in the dark but hopefully someone with some more knowledge on the subject will be able to help shortly Quote Link to comment Share on other sites More sharing options...
David P Posted June 9, 2013 Share Posted June 9, 2013 (edited) Noz, replied bits will be with you Tuesday at the latest. David thanks for getting back to me. Replaced the leads today, the last of noz's parts. Still the same issue. Replaced the fuel pump to the stock one...still showing 0 on my pressure gauge, the gauge did move to slightly above 0 on start but then dropped back down. I removed the gauge whilst the car was running and the fuel just trickles out slowly I would assume that the fuel pressure should be a lot higher than this? I am at a bit of a loss now. Help!? I was expecting a call that hasn't happened, but now that I'm home I'll post it. I'm not aware of what pump swappery you've been up to, but think you may have fizzed the N/A fuel pump ECU. Swap it for a T.T. fuel pump ECU and that should get you going. Fuel pump ECU's T.T. left N/A right Edited June 9, 2013 by David P (see edit history) Quote Link to comment Share on other sites More sharing options...
David P Posted June 9, 2013 Share Posted June 9, 2013 After our chat, here's some useful info, ignore the variable resistor because when Mr T. wrote the Supra Bible he forgot there wasn't one! Quote Link to comment Share on other sites More sharing options...
Fly Posted June 9, 2013 Author Share Posted June 9, 2013 Cheers David I'm underway with those checks. Quote Link to comment Share on other sites More sharing options...
David P Posted June 10, 2013 Share Posted June 10, 2013 Here's a couple more. Check the injectors you're using are actually low impedance and I suspect that you have the FPG on the return line. Quote Link to comment Share on other sites More sharing options...
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