Announcement

Collapse
No announcement yet.

2556 Engine stalling bad electronic ignition?-gctid814031

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

    2556 Engine stalling bad electronic ignition?-gctid814031

    I have had numerous posts while rebuilding a 2556 1988 5.7 OMC Cobra. All of last year we could not get this engine to run correctly.

    Between last season and this season I had the quadrajet rebuilt, bought a new 1/4" carb gasket. Installed new risers, had the intake boiled out, had the heads rebuilt, new exhaust manifolds, installed a new Carter fuel pump, changed the one way hose valve for the gas tank, removed the gas tank pickup to make sure it was clean, changed the gas tank hoses and vent, changed, New spark plugs, wires were changed last year, cap and rotor were clean. I installed a brand new electronic shift interrupter switch. I also installed a new electronic ignition which was specifically made for electronic and or old fashioned points ignitions. All of last year it would stall at 2500 rpms and above. This year I pulled the distributor. Was told by a mechanic no wobble looked ok. Reset timing to 3degrees. Now I can get to 3200 - it wont stall however it will not get up to 4200 where it should be WOT. After all of this it still stalls when I lower the idle enough to try to shift and the idle is lumpy. Therefore I decided enough and removed the Electronic ignition plate and reinstalled the original points, set them to exactly 17 degrees. Reset the timing again.

    Finally I am able to get this engine to idle smooth at about 600 rpms or enough to allow me to easily shift. The interrupter switch works as intended. I understand idle has to be under 700 (actually 600) for this OMC shift switch to allow the dog clutches to reengage. Starts well now. It is shifting without stalling now. Next step is to get her in open waters and see if it will hit 4200 RPMs. Too windy today will try this week. Thoughts???

    #2
    yes the idle should be at 600 or lower i have the exact same set up except i have a 1409 edelbrock carb. i also have had lots of trouble with mine after new engine was put in i still have the old petronix distributor but have upgraded the distributor to electronic ignitor ,could not get mine to run right finally found out it was the wrong coil now i use mercruiser coil and runs fine ,max. rpm for me 4100 rpm , 26 mph ,propellor 15.5 x 13 , please keep me informed would like to hear your max. rpm, speed and prop. size.cobras don't like hard shifting wiped out my forward gear had to replace my drive unit costly lesson
    1988 flybridge trophy bayliner 2556 ,mercury 5.7 lit. OMC cobra out drive 76 hrs. on new package,
    located in ketchikan ak,name DOMINION

    Comment


      #3
      could you tell me what your top rpm and speed is and what prop. you are using i have the same set and still trying to fine the correct prop. thanks Dennis
      1988 flybridge trophy bayliner 2556 ,mercury 5.7 lit. OMC cobra out drive 76 hrs. on new package,
      located in ketchikan ak,name DOMINION

      Comment


        #4
        Sorry to hear, sounds like a rough time sorting out your rpm issues. Your 88 will likely be running a mechanical advance system in the distributor (weights/springs), you had it checked for wobble etc. but has the timming advance curve been looked at?
        Dave
        Edmonds, WA
        "THE FIX"
        '93 2556
        Carbureted 383 Vortec-Bravo II 2.0:1 18 1/4x19 P

        The rebuild of my 2556 https://www.baylinerownersclub.org/f...76?view=thread
        Misc. projects thread
        https://www.baylinerownersclub.org/f...56-gctid789773

        Comment


          #5
          everything checks out nobody seems to know what the correct prop would be for the set up for this package even bayliner ,the factory prop was a15.5 x 15 that gave me 3800 rpm put on a 15.5 x 13 now i am at 4100 rpm nothing wrong with the engine just unable to find somebody that has the same set up
          1988 flybridge trophy bayliner 2556 ,mercury 5.7 lit. OMC cobra out drive 76 hrs. on new package,
          located in ketchikan ak,name DOMINION

          Comment


            #6
            What are the progressive and total advance looking like (as in graph form)...... and at what rpm is the system "Full In"?

            .
            Rick E. Gresham, Oregon
            2850 Bounty Sedan Flybridge model
            Twin 280 HP 5.7's w/ Closed Cooling
            Volvo Penta DuoProp Drives
            Kohler 4 CZ Gen Set

            Comment


              #7
              FINALLY!!!! I finally figured out what the issue was with this engine. 2 issues - As stated I switched back to points which made the engine idle a bit better. Therefore I was returning the electronic ignition. Went to put it back in the box and noticed the instructions. In typical male fashion I never read them. Well..... if the distributor rotates counterclockwise the plate is installed in a different location whereby only 1 screw hole line up and you only use the one screw! I removed the points and went back to the electronic plate. - Amazingly it idles perfect at 600 and I can now shift and dock without stalling. Regarding not being able to get to 4000 RPMs+ I spoke to a mechanic last week who explained if the valves are over torqued the engine can not get enough air and therefore will not draw enough fuel. I pulled the rockers - not easy since near everything has to come off to get to them. Then adjusted the vales to 1/4 turn once the tapping went away as my mechanic described being the easiest way to adjust them. I had to back off almost 2 full turns before I could hear the tapping. Reinstalled the rockers and finally Smooth, 4000 + rpms!!! I have the timing set to 3 degrees. If I go to 5 degrees would I get more rpms at the top end??? This engine should hit 4500 but for now I am happy at getting to 4100 after al this time. Thanks everyone for all of your help and suggestions!

              Comment

              Working...
              X