Announcement

Collapse
No announcement yet.

Can These Go Intermittent ????

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

  • Can These Go Intermittent ????

    My guess is yes. Starting this saw is hit or mis, has been for several years. Yesterday it wouldn't start, I checked for spark and there wasn't any. Checked the on / off switch and it was OK, even disconnected it and still no spark. tried a new plug, no spark. This is a solid state ignition module, no points or condenser.
    Late last night I decided to give it a try, it started right up, I cut some wood, it ran fine. I shut it down, pulled the plug grounded the end of it and cranked it over and saw a big blue spark. This morning, no spark. Removed the module, set the air gap, no spark
    My past experience with ss modules since the days of the old GM HEI coils it they either work or they don't. Thoughts...............

    JL.....................


  • #2
    Yes, they do. I've has 100's of dead and "suspect" coils in my days as a small engine service tech. But before you dump it, check your ignition lead and plug spring clip, and the case ground to the coil (look for corrosion on the case between the coil). If the engine is isolated by rubber mounts from the main case (yours isn't), make sure the ground lead bridging the two is in place.

    Comment


    • #3
      Lakeside...... thanks for the info. There is no rust or corrosion. Everything is so oily in there it could never rust. I cleaned everything. Other than the plug wire there is one other wire coming out of the coil and goes to ground. Everything is clean.
      Is there a way to check it with an ohm meter???

      JL................

      Comment


      • #4
        If it's something in the coil or solid state module (most likely over the coil with what your describing) then pay attention to the temperature in which your trying to start the unit in, my guess is once it falls below a certain temp then there is an internal disconnect of some components,,, sometimes it works the other way and heat can cause this, but I think yours would be activated by cooler temps as you said once started you did allot of cutting...

        When something is "hitNmiss" in an ignition system like you describe this is your single biggest cause, temperature... as long as all other things like obvious wiring are checked out... next can be humidity...

        Comment


        • #5
          I was thinking temperature too, but yesterday it was about 50 degrees here through out the day. When I did get it running the temp. hadn't changed. However when it was running as you know everything gets pretty hot and it still ran and had spark after I shut it down. I can try warming it up with a heat gun and see what happens. Humidity I have to question as the module is sealed in molded plastic.

          JL..............

          Comment


          • #6
            Usually electrical components either work or they don't. But just to make things interesting there are always exceptions to the rule.
            I remember when Ford's first generation electronic distributors came out there was an intermittent open in the circuit for the magnetic pickup inside of the distributor. The magnetic pickup coil's purpose was to pick up signals from the spinning reluctor on the distributor shaft in order to signal the the coil and hence trigger the spark.

            Some of the pickup coils would develop an open circuit when hot and render the ignition system dead. Once cooled off the the circuit would once again be reestablished. I remember once checking the ohm reading on one of these coils when in the no-start condition. I think the reading was supposed to be about 900 ohms. I had an open circuit across the pickup coil's leads at this point. I removed the dist. cap, let things cool off while I watched the ohm meter and bingo the tiny wires inside the coil reestablished continuity and all was good again until the next heat induced open occurred again.

            I remember at the time reading about Ford's search for an answer to the random issue with some of these pickup coils. I found out that they traced the problem to the plant in Italy where women were employed to assemble and spool them by hand. Apparently they found out that when some of the women went through their menstrual cycle they emitted more acid through their skin and this ultimately broke down the thin layer of varnish/insulation on the windings and this ultimately lead to random failures in some of these pickup coils.

            I know, more than you need to know, and very strange, but true.
            I tried to find some on line documentation for this, and I'm sure it's out there somewhere but this happened almost 40 years ago now so it would take more digging than I care to commit myself to at the moment.
            Last edited by Willy; 10-21-2014, 05:40 PM.
            Home, down in the valley behind the Red Angus
            Bad Decisions Make Good Stories​

            Location: British Columbia

            Comment


            • #7
              Willy that's crazy - if true that's incredible detective work...

              As far as fords having that trouble you describe so did certain year honda's, I used to take ice with me to diagnose and could at least get people mobile enough to get back to my shop... pick-up - pulsar or trigger coil they called them - think the year was around 91 or so VPT would probably remember.


              Joe could also be the low temp of the night before - makes things disconnect and then takes a certain amount of heat to re-connect again,,, and if the low never gets too low it may never disconnect and even though the days high is not as warm as others it may still start and run just fine... can be tricky that's for sure.

              Comment


              • #8
                Pull the wire to ignition switch. The switch may have oil in it shorting out the coil with the switch in the run position. Sometimes heating the coil in a toaster oven on warm for a few hours will dry them out if they have moisture in them causing the short. There really isn't much else to do after that except find another ignition if you like the saw. Mike

                Comment


                • #9
                  I have to agree, to come to a conclusion like that.
                  But Willy you never told us the rest of the story........ what did they do about it????? Lay all the woman off towards the end of the month?

                  JL.............
                  Originally posted by A.K. Boomer View Post
                  Willy that's crazy - if true that's incredible detective work...

                  As far as fords having that trouble you describe so did certain year honda's, I used to take ice with me to diagnose and could at least get people mobile enough to get back to my shop... pick-up - pulsar or trigger coil they called them - think the year was around 91 or so VPT would probably remember.


                  Joe could also be the low temp of the night before - makes things disconnect and then takes a certain amount of heat to re-connect again,,, and if the low never gets too low it may never disconnect and even though the days high is not as warm as others it may still start and run just fine... can be tricky that's for sure.

                  Comment


                  • #10
                    Originally posted by Mike279 View Post
                    Pull the wire to ignition switch. The switch may have oil in it shorting out the coil with the switch in the run position. Sometimes heating the coil in a toaster oven on warm for a few hours will dry them out if they have moisture in them causing the short. There really isn't much else to do after that except find another ignition if you like the saw. Mike
                    I did disconnect the switch and it made no difference.

                    JL.................

                    Comment


                    • #11
                      Originally posted by JoeLee View Post
                      I have to agree, to come to a conclusion like that.
                      But Willy you never told us the rest of the story........ what did they do about it????? Lay all the woman off towards the end of the month?

                      JL.............
                      LOL, I'm not sure, gloves, level winders???
                      I never did hear what was done to change their assembly protocol but I can assure you even I couldn't have made that one up.
                      Home, down in the valley behind the Red Angus
                      Bad Decisions Make Good Stories​

                      Location: British Columbia

                      Comment


                      • #12
                        I went through 5 faulty magnetos a few months ago. Was hell getting the shop to believe me they all died. Took em about a month to finally 'test' them and find that they where indeed all faulty and give me my damn refund. (Trying a 20 year old magneto from another motor on this motor worked fine, Was using exact cross ref for motor but non B&S brand, eventually got them to bring in a genuine B&S magneto for $5 more and its worked fine since)

                        They would last 3 seconds to 3 minutes outta the box and die. Some would even come back to life the next day for another minute or two.

                        Yes, HV components especially do go intermittent.

                        When the magneto on my motorized bike died, it kept sputtering out, randomly being fine.. loss of power, more fine, fine only at wide open throttle/high rpms, etc.

                        Once they arc over internally they randomly can work at times, but the arc causes carbon deposits and usually makes them fail soon after.
                        Play Brutal Nature, Black Moons free to play highly realistic voxel sandbox game.

                        Comment


                        • #13
                          Originally posted by JoeLee View Post
                          My guess is yes. Starting this saw is hit or mis, has been for several years. Yesterday it wouldn't start, I checked for spark and there wasn't any. Checked the on / off switch and it was OK, even disconnected it and still no spark. tried a new plug, no spark. This is a solid state ignition module, no points or condenser.
                          Late last night I decided to give it a try, it started right up, I cut some wood, it ran fine. I shut it down, pulled the plug grounded the end of it and cranked it over and saw a big blue spark. This morning, no spark. Removed the module, set the air gap, no spark
                          My past experience with ss modules since the days of the old GM HEI coils it they either work or they don't. Thoughts...............

                          JL.....................

                          I've always had new B&S engines some "points" others with induction?? coil ignition (no points") and Honda engines none with "points".

                          I've never had a failure although the "point" engines just needed re-adjustment and spark plug clean up every two years or so.

                          If I have a fault such as the OP has, I'd take it into my supplier and he would test there and then and tell me the result. I would not bother re-installing the "old "one as I'd buy a new one and fit it and off I'd go with my engine in a matter of an hour or so.

                          If there was excessive wear at the crank-shaft bearing such that the ignition "gap" was too small I'd either buy a new engine or a new mower and leave the old one with my supplier to use or dispose of it as he willed (just a variation of my shop (and other) "binning" procedure).

                          Comment


                          • #14
                            Originally posted by Black_Moons View Post
                            I went through 5 faulty magnetos a few months ago. Was hell getting the shop to believe me they all died. Took em about a month to finally 'test' them and find that they where indeed all faulty and give me my damn refund. (Trying a 20 year old magneto from another motor on this motor worked fine, Was using exact cross ref for motor but non B&S brand, eventually got them to bring in a genuine B&S magneto for $5 more and its worked fine since)

                            They would last 3 seconds to 3 minutes outta the box and die. Some would even come back to life the next day for another minute or two.

                            Yes, HV components especially do go intermittent.

                            When the magneto on my motorized bike died, it kept sputtering out, randomly being fine.. loss of power, more fine, fine only at wide open throttle/high rpms, etc.

                            Once they arc over internally they randomly can work at times, but the arc causes carbon deposits and usually makes them fail soon after.
                            I've never had a standard magneto go bad, but this solid state magneto has to be a bit different inside since there is no points in the ignition system, were not talking a standard B&S mag with points and cond.

                            I found a replacement for $60, so I'll give it a shot. Anything more than that I probably would have scrapped the saw. I can't believe there are people selling these on ebay for $350 + Hell the saw isn't worth that!!

                            JL.............

                            Comment


                            • #15
                              Had a Citroen (car) that used to bitch on starting at times when cold, restarted fine after engine had run but not consistent start/non start when cold. Replaced coil eventually, problem went.

                              Regards Ian.
                              You might not like what I say,but that doesn't mean I'm wrong.

                              Comment

                              Working...
                              X