dbtk2 Posted February 9, 2006 Report Share Posted February 9, 2006 So I'm driving the STE down the freeway. I have my scantool hooked up because I wanted to do some testing. So I start watching injector pulse width. Keep in mind that 23 would be maxed out, its usually good to have like 20 or less for your pulse width. So I get on it about halfway and the pulse width is 20. I think "thats not good". So I slow down to about 50 (so I can get a good long run to test it with) and go WOT. The pulse width jumps up to 34! As I leave my foot in it the lowest I saw the pulse width was 27 before I let off at ~105mph. So, who thinks I need bigger injectors? Keep in mind I already have the boost turned way lower than it should be because I figured this was probably the problem. Shawn Quote Link to comment Share on other sites More sharing options...
z284pwr Posted February 10, 2006 Report Share Posted February 10, 2006 Pulse width is generally read as a percentage, anything over 85% is bad. Unless your scanner reads differently? Are you sure you aren't reading the InjBPW section? I have a hard time believing you would be reading it right, my datalogs defintely show a INJ DC and a InjBPW, which is in a millisecond reading, and DC is a percentage. I can believe the BPW would MAYBE be that high, however, i do think new injectors would be a good idea, I have pegged my stock ones over 86% at 23.12 MS according to the Datamaster log, so I'm sure you are doing the same thing, especially over 100+MPH :shock: Quote Link to comment Share on other sites More sharing options...
dbtk2 Posted February 10, 2006 Author Report Share Posted February 10, 2006 I am talking about the MS reading. 23ms is static. Mine never went down even close to 23. The computer will just keep commanding the injectors to be on longer and longer even though they are static at 23, it doesn't know this so it will raise the number higher and higher until the car richens up. Shawn Quote Link to comment Share on other sites More sharing options...
Guest TurboSedan Posted February 10, 2006 Report Share Posted February 10, 2006 datalogging information aside, is it running good? hard staring? Quote Link to comment Share on other sites More sharing options...
skalor Posted February 10, 2006 Report Share Posted February 10, 2006 Stock injectors are almost maxed out on a stock engine with ~11 psi. So, I would definitely look for a set of 30lb or bigger injectors. I would use L67 36lb injectors if you have a set laying around from your dad's car. I think some have different connectors though so check them first. I have a set of 28lb injectors that I've been meaning to put on my car so that I could tune a high octane/high boost or timing chip. Anyways, be careful with running it hard with the injectors going static. My friends SR20DET powered Sentra was maxing out his injectors(370cc) on only ~7.5 psi on a similar turbo as ours and he ended up with a burnt piston. We had 52lb injectors to put in his car, but didn't get to it yet. I miss beating M3s with that car. Quote Link to comment Share on other sites More sharing options...
dbtk2 Posted February 10, 2006 Author Report Share Posted February 10, 2006 datalogging information aside, is it running good? hard staring? Runs great and starts easily. The injectors are in proper working order, just too small. Stock injectors are almost maxed out on a stock engine with ~11 psi. So, I would definitely look for a set of 30lb or bigger injectors. I would use L67 36lb injectors if you have a set laying around from your dad's car. I think some have different connectors though so check them first. I have a set of 28lb injectors that I've been meaning to put on my car so that I could tune a high octane/high boost or timing chip. Anyways, be careful with running it hard with the injectors going static. My friends SR20DET powered Sentra was maxing out his injectors(370cc) on only ~7.5 psi on a similar turbo as ours and he ended up with a burnt piston. We had 52lb injectors to put in his car, but didn't get to it yet. I miss beating M3s with that car. I have the stock 36lb. injectors from my dads GTP lying around, but I don't think it would be a good idea to go to something that big. At least not until I am able to do some tuning. I haven't bought any of the chip tuning stuff I want to get yet, have to pay bills first and see what i have left. I'll probably wait for my tax return. Once I can tune I think I will throw those injectors in there and they should be large enough for basically anything I wantdo....he ran 12.7's with them and I don't want to run any quicker than that and I have a lighter car anyways. I know I really should be careful with it because running with static injectors is never good. Thats one of the reasons why I turned the boost down. Otherwise I'd be running 12psi or so. But the only reason the pulse width is that high is because of how rich the chip wants the engine to run, the 02's are pretty much exactly where I want them right now (slightly lower than I would like but good enough, they are in the 880-890 range, I'd like to see 910 but 880 should be fine) since the computer can't make it run any richer so I'm not really worried. When I sold the Lumina the injectors were running static in that, pulse widths peaked at 27ms and then slowly creeped down to 24ms., but it was running 940 02's so it was fine. With any more mods it would definately need injectors though. Shawn Quote Link to comment Share on other sites More sharing options...
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