randy 77zt Posted January 19, 2004 Share Posted January 19, 2004 what is max size that can be run with smooth idle?dont want to go too small or too big.want motor to idle in traffic .found new 42 lb injectors on ebay for $279 a set.these are oem ford lightning truck injectors.getting ready for new efi system.car will be used for a work/track car.found theses in both bosch and lucas-any body notice a difference?also some sets of bigger injectors on ebay advertised for a supra.car would get 24 mpg with oem zxt efi.but it quit working correctly and i dont feel like messing with it. Quote Link to comment Share on other sites More sharing options...
Guest Nic-Rebel450CA Posted January 19, 2004 Share Posted January 19, 2004 It has always been my understanding that since the ECU controls the injectors, there really isnt a worry of having too large of injectors. The ECU should regulate the amount of fuel that is sprayed and not spray too much, or too little. I dont see any reason that larger injectors would cause any problems with idle or mileage unless the injector was of poor quality and the ECU wasnt able to regulate the flow well enough. I am sure some fellows with more experience will chime in to confirm or explain otherwise. Quote Link to comment Share on other sites More sharing options...
Xander Posted January 19, 2004 Share Posted January 19, 2004 It has to do with the resolution of the injection computer. Lets say your computer has a resolution of 0.1 ms (like megasquirt). this means that you can only increase or decrease the injector opening times with 0.1 ms. If you engine needs 1 ms of injection at idle than the smallest correction it can make is 10 %. This can make it difficult to tune your idle mixture So you should not go to big with your injectors. Quote Link to comment Share on other sites More sharing options...
Kennysgreen280zt Posted January 19, 2004 Share Posted January 19, 2004 I am running 440cc supra turbo injectors with no problems other than having to make a new fuel rail for them. BTW I have SDS to control them ~Kenny Quote Link to comment Share on other sites More sharing options...
Z-Gad Posted January 19, 2004 Share Posted January 19, 2004 I ran 550cc and had no probs. @ idle either... Quote Link to comment Share on other sites More sharing options...
Doug71zt Posted February 1, 2004 Share Posted February 1, 2004 52 lb/hr in my car with SDS - good idle - lots of fuel. Doug Quote Link to comment Share on other sites More sharing options...
Lockjaw Posted February 6, 2004 Share Posted February 6, 2004 I got 420cc running 56 psi static fuel pressure, with no problems. Quote Link to comment Share on other sites More sharing options...
SleeperZ Posted February 6, 2004 Share Posted February 6, 2004 Actually, the idle problem with big injectors relates to the minimum time the injector can open and close. There is a significant amount of minimum time the injector stays open before you can close it, so a large injector on a small engine may give too much fuel for a smooth idle. So if the above people reported no trouble with 500cc/min+ injectors, chances are you won't have any problems either, as it doesn't have much to do with the ECU. Quote Link to comment Share on other sites More sharing options...
randy 77zt Posted February 7, 2004 Author Share Posted February 7, 2004 lots of injectors for sale on ebay-going to get NEW injectors.after completeing a long project i want it to fire and run with no problems.car is used to commute to work.i have a van that i use for a pick up truck but car gets better gas milage. Quote Link to comment Share on other sites More sharing options...
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