Results 1 to 15 of 41

Thread: 1972 Elcamino 1993 Camaro Z28 LT1 T56 6 speed

Hybrid View

Previous Post Previous Post   Next Post Next Post
  1. #1
    Fuel Injected!
    Join Date
    Jan 2014
    Location
    AZ
    Posts
    93

    1972 Elcamino 1993 Camaro Z28 LT1 T56 6 speed

    Hello to all. been lurking here and there gathering info for my camino. I am on a couple other forums and have been gathering there as well. I have just started tinkering with my ride and have to say this site and the others have been a lot of help. I know the LT1 is kind of outdated but the cool thing is a lot of the tools and tricks have been tried and proofed so it helps a lot. I am not new to wrenching have done it all my life as a hobby. But this is my first injected ride.
    So for a little history: 1972 Elcamino 1993 Camaro Z28 LT1 T56 6 speed. I have gone through the tranny and upgraded to a viper mainshaft brass keys and shifter fork buttons. That spins a gm 12 bolt with disc brake conversion 4.11 gears and a Eaton locker no hop bars and adjustable upper control arms. The computer has been changed out for a 95 ECM. It is easier to get a replacement (at the time I was having trouble there were none to be found in the US) spent 2 years looking and finally on advice from Zac at Speed Scene Wiring we changed. Along with a more readily available supply I also got the benefit of sequential fire injection. I also just recently converted to a Bailey engineering LTCC conversion. Firing NGK TR55's gapped at .060. It's running a BBK 58mm throttle body, K&N Cold air kit picking up on the left front fender. Racetronix in tank fuel pump and dedicated power supply harness. Headman Elite mid length headers with 3 inch collectors dumping into 3 inch 2 chamber Flowmaster Delta force silencers and then 3 inch all the way over the axle to the bumpers all mandrel bent. I have a 2.5 inch crossover to help with the sound a little.
    So I have been slowly getting things sorted and have found some things out as well. I am have been datalogging and have noticed that I am predominately at 108 on the blm readings. After looking here at some threads i found that i may need to scale back my injector values. I am running 45psi at idle and 44 at 2k unloaded of course just setting in the drive. cracking the throttle jumps it to 50psi. So i am figuring that is why I am stuck in the 108's. Also my log graph looks like a seismic even for a 7.9 earthquake. Not sure if it's my logging or if my system is that wacked. Truck runs great be it a little fat but not smoking just smells that way.
    If anyone has a log of a good run with Tunerpro V5 I would like to get a look at it to see if I am seeing it right
    Last edited by beestoys; 01-29-2014 at 07:56 AM.

  2. #2
    LT1 specialist steveo's Avatar
    Join Date
    Aug 2013
    Posts
    4,007
    so just to be clear, you are running 1993 stock injectors with a 1994-1995 harness and ecm?

    this is important; as the stock '93 injectors are 22lb, but the '95 pcm is set up for 24lb injectors by default. add some extra fuel pressure and you're going to be way out to lunch.

    but it should be running lean, not rich!

    the stock injector constant assumes 43.5lbs tops, you're hitting 50lbs. this is max, without any vacuum to the regulator.

    so you adjust for fuel pressure using sqrt(actualpressure/ratedpressure)*injectorsize. that gives you sqrt(50/43.5)*24=25.73

    what is your injector constant right now anyway?

  3. #3
    Fuel Injected!
    Join Date
    Jan 2014
    Location
    AZ
    Posts
    93
    Steveo
    The harness is a custom build by Zac, it incorporates a 95 ECM running the 93 hardware. I have the EGR blocked and no air pump it has the AC circuit still in there but it's not used right now. Also I have no charcoal canister or any emissions equipment for that matter. It is running the knock sensor in the stock location.

    I'll have to check to see what the constant is. I did download the tune that Zac put in for me so I'll see where he has it set. I am new to this so I'll see if i can find it. (man there's a lot of info in the tables and scalars) lol.

    Yes and that 43.5 max is actually what I am running at under normal cruise (actually 44 no load in driveway). So I am figuring that is why the ECM is trying to pull it back all the time. On a side bar changed out the plugs pulled out E3's and they were all dark brown so that confirmed my believing it running rich. I also noted that the pressure gage is not holding line pressure after the pump cycles. I ended replacing the stock pump for this issue as well as a flat spot. So I am thinking i have either popped another check valve or I have a bad injector. We are going to scope it this weekend and see if any of them are leaking. I will also to an infrared check on the primaries to verify all appears to be balanced. I checked it when we first lit off the new ignition system and they were good but I'll double check them.

  4. #4
    Fuel Injected!
    Join Date
    Jan 2014
    Location
    AZ
    Posts
    93
    Steveo
    Looks like it's set at 24.912 so with that I am thinking Zac made a correction for the bigger injectors. I'll get some hard numbers and run them through that formula. This is why I wanted to go down this road. Giving someone a generic idea is good but I have found real world is never generic.
    On the lean note if I have more pressure than factory shouldn't it be running fat hence my BLM's being at 108 which would tell me the system see's that and is trying to pull fuel out?
    Last edited by beestoys; 01-29-2014 at 06:22 PM.

  5. #5
    LT1 specialist steveo's Avatar
    Join Date
    Aug 2013
    Posts
    4,007
    no thats the thing, your injectors are smaller if they're from a 93. i actually screwed my math up above, i did it for 24lb injectors. yours are 22lbs. your injector constant should be closer to 23.58

  6. #6
    Fuel Injected!
    Join Date
    Jan 2014
    Location
    AZ
    Posts
    93
    Ok I see so calculate at 22 I'll run the numbers with that then and see what happens. This thing is violent now I can imagine what it's going too be when it's leaned out some and running stronger.

  7. #7
    RIP EagleMark's Avatar
    Join Date
    Feb 2011
    Location
    North Idaho
    Age
    63
    Posts
    10,477
    The 24.912 is a stock setting for some... Calculating injector flow and setting Injector Off set voltage in calibration is always a better first step in tuning, before tuning! Getting it right should get the BLMs closer but tuning is still in order.

    1990 Chevy Suburban 5.7L Auto ECM 1227747 $42!
    1998 Chevy Silverado 5.7L Vortec 0411 Swap to RoadRunner!
    -= =-

Similar Threads

  1. Can an 0411 operate a 1993 4L60E?
    By dave w in forum OBDII Tuning
    Replies: 16
    Last Post: 10-07-2016, 09:39 AM
  2. Putting a GM TBI system on my 1972 Ford F-250
    By akforceten in forum Fuel Injection Writeups Articles and How to New and Old
    Replies: 20
    Last Post: 10-17-2015, 05:43 PM
  3. '87 Camaro manual 5.7 -- bin to use?
    By brianko in forum GM EFI Systems
    Replies: 15
    Last Post: 11-15-2012, 09:54 PM
  4. 1993 Chevy ½ ton Drag truck
    By 1leg in forum GM EFI Systems
    Replies: 17
    Last Post: 02-25-2012, 11:21 PM
  5. 1993 Corsica 2.2 liter Stalling when cold
    By historystamp in forum Gear Heads
    Replies: 25
    Last Post: 01-20-2012, 12:04 AM

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •