Announcement

Collapse
No announcement yet.

Starts, Idles OK for 5 Sec, then Floods 8F and $59

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • Starts, Idles OK for 5 Sec, then Floods 8F and $59

    I've been having a problem with a collapsed lifter and this issue popped up over the last year or so that I haven't been driving the car.

    After I started to develop a ticking lifter, I changed to 36# injectors. I previously had 30# in there. I don't recall my thought process at the time, but it seemed like I was running out of fuel up top and thought I'd try switching to 36s.

    Now the car will start up, idle ok for a few seconds (AFR ~15) then it goes off the chart rich (as in barely running). Originally I was running $8F, I tried changing the BPC vs EGR to the correct number based on the new injectors, and it just runs super rich. Changing BPW does nothing, forcing open loop did nothing, and I do have the EGR disabled in the code.

    I also decided I'd give Code59 a try since I was annoyed at $8F and my damn shift light. It also seemed like $59 might have more potential for a manual trans car. Got a 3 bar map, picked one of the 60degree bins to start, and changed BPC. Bottom line the same thing occurs. It starts ok, then goes pig rich.

    36# on a 2.8 seems a bit high, but not unreasonable. I'm having trouble understanding why BPC is having no effect in either code. No error codes are being thrown.

    Anyone have any ideas?

    Sorry if this seems jumbled, trying to throw it together on my lunch break

  • #2
    What do MAP, coolant and air temps read?
    MinusOne - 3100 - 4T60E
    '79 MGB - LZ9 - T5
    http://www.tcemotorsports.com
    http://www.britishcarconversions.com/lx9-conversion

    Comment


    • #3
      it almost sounds like a code gets triggered and causes a default value to be used that is very wrong for the application.
      1995 Monte Carlo LS 3100, 4T60E...for now, future plans include driving it until the wheels fall off!
      Latest nAst1 files here!
      Need a wiring diagram for any GM car or truck from 82-06(and 07-08 cars)? PM me!

      Comment


      • #4
        Finally got back to my car, it's stored at my parent's house for the winter so it's not frequent I get to wrench on it. On a cold start (55-60*) here today.

        Coolant:= 54.5 F or 12.5 C
        MAP:= 28 kPa
        MAT:=110.92 F or 43.85 C


        It ran so rich it was dumping fuel, as in liquid gas coming out the leaking joints near the removable section of my exhaust (obvious exhaust leak).

        Second Run

        Coolant:= 128.75 F or 53.75 C
        MAP:= 25 kPa
        MAT:=108.15 F or 42.31 C

        No SES light indicated.

        Still Struggling on this one.

        Injector Base Pulse Width = 1.2ish

        Changing BPC seems to affect crank fuel, and that's about it. I dropped BPC vs EGR way down to about 75 and the car wouldn't start. Bumped it back up to 110, and it would start, but still managed to run super rich. This is with 36# with a 2.8. 110 still seems low.

        Comment


        • #5
          Ive been using Code59...

          One thing I noticed is that ALL their bins have the BPC at 158. (Like a stock injector truck, vs. one with 90# injectors) and they all seem to run fine.

          What they seem to do is scale the whole VE table down... Not sure why no one ever talks about this, lol, but it's definetly how they tune if you look at the files in the DL section at C59.org

          When I went from 42# to 60# I just pretty much multiplied the VE table by .070 it worked, well, pretty much perfectly. [(42/60) = .70 ] I still have a few issues with 59 that are REAALLY pissin me off though... Almost enough to go with an MS3. might be the 5K stall converter and the cam, not sure.

          I can send you my C59 60# file if you like.
          11.92 @ 122 MPH 3400 91 Cavalier Z24 Intercooled S/C. -totalled-
          10.56 @ 130 MPH 3900 LZ9 87 IROC Z28 Intercooled GT4088 Turbo

          Comment


          • #6
            Mars, thanks for the tip on VE scaling. If you don't mind sending it, your file for C59 would be very helpful.

            What issues are you still having with C59?

            Comment

            Working...
            X