SS_bnoon_SS Posted June 17, 2008 Report Share Posted June 17, 2008 OK, I added the 42# injectors a week or so ago and at the end of last week I got a check engine light. Checked it out and it's a random misfire code. I also noticed that at idle, bank 1 is trying to add 3-4 msec of pulse width and it goes higher with increased RPM (loaded or free revving). I checked for air leaks in the intake, didn't find any. Prior to this, all fuel trims were less than 1 and O2's were spot on. I'm thinking I have a bad injector on bank 1 since they were used. I'm thinking of changing the banks with injectors (the 4 from bank 1 to bank 2 and vise versa to test). The problem should move to bank 2 if I'm right. Thoughts? Quote Link to comment Share on other sites More sharing options...
RICE EATER Posted June 17, 2008 Report Share Posted June 17, 2008 no tuning expert here... but very curious to see what you figure out.. im also having the same problem here and there.. i get it if i let the truck idle to long.. or on start up if i dont drive it right away and basily clean it out like a damn carb is loading up..haha when did your light come one.. where you driving it ? or just when it was at idle? Quote Link to comment Share on other sites More sharing options...
SS_bnoon_SS Posted June 17, 2008 Author Report Share Posted June 17, 2008 when did your light come one.. where you driving it ? or just when it was at idle? Came on the other night. It started flashing right after I started it, then stayed on solid. Quote Link to comment Share on other sites More sharing options...
misterp Posted June 17, 2008 Report Share Posted June 17, 2008 ...I'm thinking of changing the banks with injectors (the 4 from bank 1 to bank 2 and vise versa to test). The problem should move to bank 2 if I'm right. ... Yup total PITA but about the only way you will isolate a poor injector. Or, if it's misfiring at idle then a PCM injector test might point to the culprit. Mr. P. Quote Link to comment Share on other sites More sharing options...
chpspecial Posted June 17, 2008 Report Share Posted June 17, 2008 Did all of the injectors seat properly in their bungs? Just a thought Quote Link to comment Share on other sites More sharing options...
SS_bnoon_SS Posted June 17, 2008 Author Report Share Posted June 17, 2008 Yup total PITA but about the only way you will isolate a poor injector. Or, if it's misfiring at idle then a PCM injector test might point to the culprit. Mr. P. Are you talking measuring resistance on each one with a meter? Or something else??? By the way, it's only a PITA when the engine is hot and you have to wait because of fire risk. With a couple times' worth of experience, I can do injectors on these trucks in about 20 minutes or less. Super easy. Did all of the injectors seat properly in their bungs? Just a thought Yup, double and triple checked. When you lube the O-rings with petrolium jelly they seat right in no problem. No fuel leaks on top, no air leaks on bottom. Quote Link to comment Share on other sites More sharing options...
misterp Posted June 17, 2008 Report Share Posted June 17, 2008 (edited) Are you talking measuring resistance on each one with a meter? Or something else??? By the way, it's only a PITA when the engine is hot and you have to wait because of fire risk. With a couple times' worth of experience, I can do injectors on these trucks in about 20 minutes or less. Super easy. Yup, double and triple checked. When you lube the O-rings with petrolium jelly they seat right in no problem. No fuel leaks on top, no air leaks on bottom. When in diagnostic mode, you can command the PCM to perform a running ignition and/or injector drop test. Using EFILive they have a "bi-directional" menu, and you can initiate the injector drop-out test and it will display the resulting RPM while the targeted injector was disabled. So an example output would look like this - CYL - RPM #1 - 650 #2 - 650 #3 - 650 #4 - 650 #5 - 695 #6 - 650 #7 - 650 #8 - 650 and in this illustration the motor has a #5 injector that is dead, because when it was deactivated the motor's RPM did not fall. The same test via ignition coil will also point to failed secondary ignition components too. The only problem with this kind of test is that the injector has to be so far gone as to present an obvious problem at idle, in your case the weak injector might be good enough at idle and not show a big change with the drop-out test, you might have to go ahead and one-at-a-time swap all the odd inectors to the #2 hole to pinpoint the weak one. Mr. P. Edited June 17, 2008 by Mr. P. (see edit history) Quote Link to comment Share on other sites More sharing options...
SS_bnoon_SS Posted June 17, 2008 Author Report Share Posted June 17, 2008 Hummmmmm, not sure if HPT has something like that or not. I guess I get to go ask a question over on their forums. It's not something I've heard of before... Quote Link to comment Share on other sites More sharing options...
dozer Posted June 18, 2008 Report Share Posted June 18, 2008 I think HPTuners has it. Open your scanner go to VCM Controls/ Special. I think thats it where it list #1-#8 with rpm above it. Im to lazy to go conect it and check. Quote Link to comment Share on other sites More sharing options...
SS_bnoon_SS Posted June 21, 2008 Author Report Share Posted June 21, 2008 I think HPTuners has it. Open your scanner go to VCM Controls/ Special. I think thats it where it list #1-#8 with rpm above it. Im to lazy to go conect it and check. Yup, that's where it is. Thanks! Quote Link to comment Share on other sites More sharing options...
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