Page 1 of 2 12 LastLast
Results 1 to 10 of 15

Thread: Brutally hard start after reflash - COS3

  1. #1
    Junior Member
    Join Date
    May 2008
    Posts
    16

    Default Brutally hard start after reflash - COS3

    One of my personal cars as well as a few other ones I have done with COS3 on a 411 style ls1 pcm seem to have an issue with start up after I write a new file. This will happen EVERY time on my personal car and I will have to fight to keep it running for about 10-20 seconds and then it will "catch" itself and run fine.

    It almost seems as though it wont trigger the fuel pump after a reflash or possibly that it doesn't see an rpm signal right away.

    This issue only happens when we have the custom operating systems loaded.

    Has anyone else had this issue? It gets VERY annoying / trouble some when you are making a lot of tune changes.

    Thanks!

  2. #2
    Joe (Moderator) joecar's Avatar
    Join Date
    Apr 2003
    Posts
    28,403

    Default

    When you install a COS you have to also populate B3647 (RPM vs MAP) because it will contain the data from B3605 (ECT vs MAP).

    Are you sure it does not run the fuel pump...?

    What year/model/vehicle, what PCM, what OS and COS...?

  3. #3
    Junior Member
    Join Date
    May 2008
    Posts
    16

    Default

    Im not positive but I don't think it is because if I let it prime then try it is better but still not good. I am generally doing this by myself so hard to say for sure.

    The B3647 is all populated with real life numbers, here is the info

    It is a 2003 full size truck ecu ( in an engine swap deal)

    VIN: 1GCEK19T13E112090
    Operating system : 04073003

    I am not sure the original operating system as it has had this one on it for quite some time now.

  4. #4
    Joe (Moderator) joecar's Avatar
    Join Date
    Apr 2003
    Posts
    28,403

    Default

    When you flash it, are you doing a full flash or a cal only flash...?

    Also, in the text log do you notice if it completes successfully...?

  5. #5
    Junior Member
    Join Date
    May 2008
    Posts
    16

    Default

    I always just do a cal flash and it says it completes successfully. Like I said I have had this happen on other vehicles with cos3 as well.

  6. #6
    Junior Member
    Join Date
    May 2008
    Posts
    16

    Default

    Did another car today with OS 01270003 and it started up fine after every re-flash.

  7. #7
    Joe (Moderator) joecar's Avatar
    Join Date
    Apr 2003
    Posts
    28,403

    Default

    Quote Originally Posted by tirefryin_s10 View Post
    Did another car today with OS 01270003 and it started up fine after every re-flash.
    Maybe this COS is more compatible with your PCM than the other COS...

  8. #8
    Junior Member
    Join Date
    May 2008
    Posts
    16

    Default

    Quote Originally Posted by joecar View Post
    Maybe this COS is more compatible with your PCM than the other COS...
    No that os was for an older pm (1999) vs mine is a 2003

  9. #9
    Joe (Moderator) joecar's Avatar
    Join Date
    Apr 2003
    Posts
    28,403

    Default

    Hmmm...

  10. #10
    Junior Member
    Join Date
    May 2008
    Posts
    16

    Default

    still no ideas on this ? It will also start poorly if the main power to the car has been un-hooked is it possibly something with the Keep active memory?

Page 1 of 2 12 LastLast

Similar Threads

  1. Hard to start when cold
    By ferocity02 in forum Gen III V8 Specific
    Replies: 0
    Last Post: April 8th, 2014, 05:41 AM
  2. hard to start after reflash
    By andysc3 in forum Custom Operating Systems
    Replies: 21
    Last Post: March 6th, 2013, 11:44 AM
  3. hard re-start
    By amiller406 in forum General (Petrol, Gas, Ethanol)
    Replies: 4
    Last Post: March 29th, 2012, 12:39 AM
  4. Hard to start when hot
    By W_D_R in forum General (Petrol, Gas, Ethanol)
    Replies: 6
    Last Post: March 30th, 2010, 12:26 PM
  5. what is a hard start?
    By mr.prick in forum RoadRunner Real-Time PCM Emulator
    Replies: 8
    Last Post: September 23rd, 2007, 03:02 AM

Posting Permissions

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