xtremerevolution Posted April 24, 2010 Author Report Share Posted April 24, 2010 (edited) L36 injectors are 22lb/hr, which is apparently what my stock injectors were as well. If they're not enough, L67 injectors are very easily obtainable and I would just need to tune. Overkill, yes, but they may be the easiest route to take. But I am starting to think a bit here. I'm hearing from people like in this thread below that you can even run a 4.0" pulley on a top swap with stock L36 injectors. What's going on here? What does a 93% injector duty cycle as reported by the PCM actually mean? http://www.hptuners.com/forum/showthread.php?t=20973 Edit...nevermind. He has his tuning table set to 22, but is using 36lb/hr injectors. Makes sense. And L67 injectors are 36.5lb/hr Edited April 24, 2010 by xtremerevolution Quote Link to comment Share on other sites More sharing options...
RobertISaar Posted April 24, 2010 Report Share Posted April 24, 2010 i could have swore L27 or L36 injectors were 19 lb/hr... looking at the BIN, it shows the 95 L67 as using 29.2lb/hr injectors and a 95 L27 as using 19.5lb/hr... Quote Link to comment Share on other sites More sharing options...
xtremerevolution Posted April 24, 2010 Author Report Share Posted April 24, 2010 (edited) i could have swore L27 or L36 injectors were 19 lb/hr... looking at the BIN, it shows the 95 L67 as using 29.2lb/hr injectors and a 95 L27 as using 19.5lb/hr... Hmm, you could be right. In either case, do you have a better alternative to using L67 injectors? Edit...Danthurs on the bonneville forums (who apparently tunes a lot) thinks the L36 injectors are 22lb-hr. Edited April 24, 2010 by xtremerevolution Quote Link to comment Share on other sites More sharing options...
RobertISaar Posted April 24, 2010 Report Share Posted April 24, 2010 Hmm, you could be right. In either case, do you have a better alternative to using L67 injectors? Edit...Danthurs on the bonneville forums (who apparently tunes a lot) thinks the L36 injectors are 22lb-hr. L36 with 22 lb/hr would make sense... depending on how high you plan on revving the motor, and any other mods you might have planned, anywhere between 22-26 should be fine for N/A... Quote Link to comment Share on other sites More sharing options...
xtremerevolution Posted April 24, 2010 Author Report Share Posted April 24, 2010 (edited) Well the injectors from the L36 that I put in my L27 looked identical, only the new ones weren't starting to corrode and they weren't dirty as hell. So if I'm running a 93% duty cycle on 22lb/hr injectors, is that just because they're listed as 19.5 in the BIN, or do I actually need heavier injectors. Edit...Danthurs says L36 injectors are 22lb/hr and L67 injectors are 32lb/hr....at 45PSI fuel pressure. Now to figure out what my fuel pressure is? Edited April 24, 2010 by xtremerevolution Quote Link to comment Share on other sites More sharing options...
RobertISaar Posted April 24, 2010 Report Share Posted April 24, 2010 didn't know you already put L36 injectors in... hmm... now 26-30 is looking more reasonable... Quote Link to comment Share on other sites More sharing options...
xtremerevolution Posted April 24, 2010 Author Report Share Posted April 24, 2010 didn't know you already put L36 injectors in... hmm... now 26-30 is looking more reasonable... Last I checked, the L27 and L36 injectors were identical. I just put them in from an L36 because I was offered a great deal on new injectors off a crate motor, so I said to hell with it, and bought them. Can't say my car ran any different after putting them in, but at least the engine bay was prettier. Before: After: Quote Link to comment Share on other sites More sharing options...
RobertISaar Posted April 24, 2010 Report Share Posted April 24, 2010 weird... this needs to be gotten to the bottom of... don't suppose there is anything like this for 3800 engines? http://wiki.60degreev6.com/index.php?title=Fuel_injector_ratings Quote Link to comment Share on other sites More sharing options...
xtremerevolution Posted April 24, 2010 Author Report Share Posted April 24, 2010 weird... this needs to be gotten to the bottom of... don't suppose there is anything like this for 3800 engines? http://wiki.60degreev6.com/index.php?title=Fuel_injector_ratings Not that I know of. What do you need? Is it possible that the PCM is calibrated to a lower weight injector even though it has a higher weight injector from the factory? Those ratings are also at 45 psi. Danthurs looked it up and apparently fuel pressure should be at 48-55, with a 3-10psi loss at idle. Quote Link to comment Share on other sites More sharing options...
xtremerevolution Posted April 24, 2010 Author Report Share Posted April 24, 2010 (edited) I think I figured it out. What if my fuel pressure is lower; at say 40psi. Wouldn't that explain why 22lb injectors would be listed in the BIN at 19lb? I did some google searching. Seems like the fuel pressure for a 95 Regal should be around 42-47. Edit...I figured it out. Danthurs is telling me that L36 injectors: 48-55 psi with a flow of 22 pounds. The manual for a 95 Regal shows fuel pressure should be 42-47 psi. That would explain why its stored as 19 pounds in the PCM. Edited April 24, 2010 by xtremerevolution Quote Link to comment Share on other sites More sharing options...
RobertISaar Posted April 24, 2010 Report Share Posted April 24, 2010 the flowrate listed in the BIN is always at the full pressure the FPR is intended to provide. if for some reason the FPR can't get the pressure up when at WOT or with the vacuum line to the FPR disconnected, then that will effectively reduce injector size. Quote Link to comment Share on other sites More sharing options...
xtremerevolution Posted April 24, 2010 Author Report Share Posted April 24, 2010 the flowrate listed in the BIN is always at the full pressure the FPR is intended to provide. if for some reason the FPR can't get the pressure up when at WOT or with the vacuum line to the FPR disconnected, then that will effectively reduce injector size. So that explains it. If the full pressure the FPR provides is 42-47, and L36 injectors flow 22lb at 48-55lb, then listing them as 19lb should be valid, right? Everywhere I'm looking states 22lb-hr for L36 injectors, so I have no doubt about that. Seems like I still need heavier injectors. Based on this fuel pressure, L67 injectors should come in at 30lb. Quote Link to comment Share on other sites More sharing options...
RobertISaar Posted April 24, 2010 Report Share Posted April 24, 2010 all this 3800 stuff is foreign to me... all of the MPFI/SFI 660s before 2000 were rated at 43.5PSI, then in 2000, everything went to the 55PSI system. sounds like the 3800s did the same thing, just they did it when going from S1 to S2? according to witchhunter, using L36 injectors at S1 pressure works out pretty well compared to the stockers. running S2 L67 injectors at S1 pressure comes out to ~32.4lb/hr. a little big for your application, but shouldn't be enough to where it would cause idle issues. Quote Link to comment Share on other sites More sharing options...
xtremerevolution Posted April 24, 2010 Author Report Share Posted April 24, 2010 all this 3800 stuff is foreign to me... all of the MPFI/SFI 660s before 2000 were rated at 43.5PSI, then in 2000, everything went to the 55PSI system. sounds like the 3800s did the same thing, just they did it when going from S1 to S2? according to witchhunter, using L36 injectors at S1 pressure works out pretty well compared to the stockers. running S2 L67 injectors at S1 pressure comes out to ~32.4lb/hr. a little big for your application, but shouldn't be enough to where it would cause idle issues. Well then, its quite a learning experience for you huh. Do you think I'd be fine with just the L36 injectors? I peaked at 93.3% injector duty cycle at 5300 rpm, and all my runs were at 1-2 shift points. I don't know how things would change for 2-3 shift points, which might be higher. Quote Link to comment Share on other sites More sharing options...
RobertISaar Posted April 24, 2010 Report Share Posted April 24, 2010 from what you just said, you already are running L36 injectors... right? if so, at S1 pressure, they're more or less the same injectors. if you bumped up the fuel pressure to S2 levels, then that would probably get you to into the 80-85% duty cycle range... theoretically, anyways. it would be a 12.8% increase in flow, so i figured a 93% duty cycle after a ~13% increase in flow would get you in the right range, assuming the engine isn't still pulling after the 5300RPM you experienced already... Quote Link to comment Share on other sites More sharing options...
xtremerevolution Posted April 24, 2010 Author Report Share Posted April 24, 2010 from what you just said, you already are running L36 injectors... right? if so, at S1 pressure, they're more or less the same injectors. if you bumped up the fuel pressure to S2 levels, then that would probably get you to into the 80-85% duty cycle range... theoretically, anyways. it would be a 12.8% increase in flow, so i figured a 93% duty cycle after a ~13% increase in flow would get you in the right range, assuming the engine isn't still pulling after the 5300RPM you experienced already... Danthurs mentioned I'm running a bit lean for an N/A engine. What do you think of that? I'll get on the highway and do a WOT run at the 2-3 shift point and record that. That will let me know where I stand. Quote Link to comment Share on other sites More sharing options...
RobertISaar Posted April 24, 2010 Report Share Posted April 24, 2010 12:1 is lean for N/A? the theoretical point for best power is 12.9:1 and i always shoot for 12.5:1 with stuff i tune... going too rich will help cool down the cumbustion chamber, but it kills power and is hell on exhaust valves(just like late timing). Quote Link to comment Share on other sites More sharing options...
tornado_735 Posted April 24, 2010 Report Share Posted April 24, 2010 I'm watching this thread closely. It's quite the learning experience for me too! Quote Link to comment Share on other sites More sharing options...
RobertISaar Posted April 24, 2010 Report Share Posted April 24, 2010 I'm watching this thread closely. It's quite the learning experience for me too! http://www.thirdgen.org/techboard/diy-prom/288763-prom-tuning-guide-book.html most difficult learning curve i've EVER encountered, but there is SO much information it's tough to process... Quote Link to comment Share on other sites More sharing options...
mfewtrail Posted April 24, 2010 Report Share Posted April 24, 2010 L27 injectors = 21.2lbs @ 43.5psi(same as the non-sc S2 3800's) according to this page: http://www.gmtuners.com/flow/index.htm Quote Link to comment Share on other sites More sharing options...
RobertISaar Posted April 24, 2010 Report Share Posted April 24, 2010 L27 injectors = 21.2lbs @ 43.5psi(same as the non-sc S2 3800's) according to this page: http://www.gmtuners.com/flow/index.htm so they are essentially the same injector... just that the S2 has a FPR that bumps up to a higher pressure to get more flow. Quote Link to comment Share on other sites More sharing options...
xtremerevolution Posted April 25, 2010 Author Report Share Posted April 25, 2010 Car threw a code 342 earler today; cam sensor. I'm willing to bet this has something to do with my tune. This better not take me a month to learn how to tune. I can see it taking me a week, but I don't want to spend my summer trying to tune the Regal. Quote Link to comment Share on other sites More sharing options...
RobertISaar Posted April 25, 2010 Report Share Posted April 25, 2010 fun fact that may be related: earlier i was reading a lot of threads on TGO, there was someone getting a lot of false knock and no reasonable explaination... the motor eventually got pulled(i think) and he noticed what was roughly a silver dollar sitting on his crossmember: it was his timing cover. or part of it, actually. his cam cut a hole out of it... makes me wonder if you're getting valvetrain noises messing with the knock sensor... alldata says the only time that code will set is if the engine is running and the cam signal is lost for 5 seconds or more... almost sounds like could have cam walk. it could explain the "knock" as well if it's hitting the timing cover... Quote Link to comment Share on other sites More sharing options...
WrathOfSocrus Posted April 25, 2010 Report Share Posted April 25, 2010 so they are essentially the same injector... just that the S2 has a FPR that bumps up to a higher pressure to get more flow. I'm quite new to the 90 degree scene. My friend just bought an '01 Impala and the motor grenaded a connecting rod. Our replacement motor must be pre '00 because the injectors, engine cover (still says 3800 series II), rear exhaust manifold outlet, alternator bracket and A/C brackets were all different. The newer motor used Multec 2 injectors whereas the replacement motor has the multec 1 injectors like you replaced yours with. I was under the impression that ALL multec 1 injectors used in GM applications were considered running at 43.5 PSI and ALL multec 2 injectors got the 55 PSI FPR. The older FPR has 050 inside an oval and 'MADE IN GERMANY' stamped into it. The newer one has a slightly different top hat shape and no discernable markings. My point is I believe the Multec 1 injectors you are using already were running at the same pressure as the FPR your car left the factory with. It wasn't until they changed injectors that the FPR was changed. Unless someone knows something I don't. In any case I scored a set of Multec 1 injectors. Just for doing an engine swap! Kind of reminds me of a Lender's Bagels commercial. In any event I hope that helps or that someone can explain to me more about these injectors if I am incorrect. Quote Link to comment Share on other sites More sharing options...
xtremerevolution Posted April 25, 2010 Author Report Share Posted April 25, 2010 fun fact that may be related: earlier i was reading a lot of threads on TGO, there was someone getting a lot of false knock and no reasonable explaination... the motor eventually got pulled(i think) and he noticed what was roughly a silver dollar sitting on his crossmember: it was his timing cover. or part of it, actually. his cam cut a hole out of it... makes me wonder if you're getting valvetrain noises messing with the knock sensor... alldata says the only time that code will set is if the engine is running and the cam signal is lost for 5 seconds or more... almost sounds like could have cam walk. it could explain the "knock" as well if it's hitting the timing cover... If I have cam walk on this engine, I swear I'm going to lose it. I do not have the time to drop the engine, pull the timing cover off, and try to fix whatever it is that's allowing that cam to move around in there. How can I further diagnose this to see if it truly is the case? Do you have a link I can look at? Quote Link to comment Share on other sites More sharing options...
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