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It runs great when it starts but does not get fire to the plugs except on about the 10th try with the key or sometimes it will start with the first turn of the key and then not again. Battery is reading 12.8 V and I have tried bypassing the kill switch. When the key is in the on position I can hear the fuel pump pressurizing the system and if an when it starts after I shut it down I hear the 5 or so clicks as usual. It's a real head scratcher so any suggestions would be greatly appreciated.
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how do you know that the plugs are not sparking? -
I attached a spark plug tester between the plug wire and the spark plug and had my wife watch it as I turned it over - every time it turned over and didn't start she said that it didn't light up - when it did start you could watch the spark through the tester light up - check the other 3 cylinders - same resultComment
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pretty easy testing if you can make it stay broke.
you do realize it is a 12v transistor switched ign system.
the loss of two ign coils is stretching the imagination.
the loss of both pulser coils really stretches it.
now the loss of 12V from the main relay not so much a stretch. there is also a 12V+ and - junction blocks.
it can all be tested with a meter but YDIS would be faster.
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Mr. Rodbolt - I had similar thought about the coils and decided to look at the main relay but could not test it with the relay on the boat - unplugged to relay and did a continuity test with no power to the relay and according to the manual the Red/Yellow and the Red wire should have continuity with 12 Volts - during my test without 12 Volts to the relay it had continuity from red wire to one of the Red/Yellow wires and no continuity to the other Red/yellow wires - that kind of made me think the relay my be bad but I am a complete amateurComment
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with "key on" the red/yellow wires to the coils should be constant "hot"
(the ECM grounds the coils to fire)
so start by seeing that you have power at those connections
if you don't, then backtrack to find why notComment
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Mr. Deal when I get back to the lake this weekend I will give it a try - I just ordered the YDIS that Mr. Rodbolt suggested that sounded like a good investment - part swapping can get expensive on these things - thank you for your helpComment
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go to radio shack. buy some jumper leads.
back probe the connectors with paper clips. presto you can now test things in real time.
if you have a digital meter with an Hz function you can test injector anf coil primary function as well.
myself this is where I would bust out my old trusty stevens CD-77.
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No fair telling folks how it works. That is a bad deal. Folks don't want to know how a system works. Folks want to know what is broken.Originally posted by fairdeal View Post
Trouble shooting is infinitely more challenging when the theory of operation is not known.Comment
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What do you do when they will not even try to troubleshoot?Originally posted by boscoe99 View PostComment
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Fellas - I do not mind reading, learning and trying but I am on the low end of the learning curve with these fuel injected "modern" engines. Up until about four months ago I had an old 1985 Mercury that just ran without any major problems for the better part of 30 years - Those old engines were easy - these new modern engines with computers and fuel injection are a different animal. Thank you for all of the tips so farComment
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that EFI system has been around over 20 years. it aint exactly new.
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I accidentally posted this to an old thread and was redirected back to my thread
Last week I thought I had a bad main relay as my 2005 F115 would crank 12 volts to coils no spark and no voltage at fuel injectors - Since then I have replaced the main relay and it appears that it was not the problem - now when I turn the key to the on position the alarm buzzer goes off and continues to sound until I crank the engine - engine cranks freely but no spark at plugs - 12 volts at coils, no voltage at fuel injectors or throttle position sensor . Bought the YDS software and installed and set device to COM 1 and followed instructions - plugged into diagnostic port turned switch to on and software will not communicate with engine. I have a feeling that this may be more than I can handle but would like to try it anyway. I will continue to read the wealth of information on this forum and hopefully learn something along the way. Again all suggestions and jabs appreciated.Comment
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well kinda
the ECM does NOT ground the coil primary to spark. it ungrounds them.
just like a set of points in my old 61 Studebaker.
see it aint hard.
instead of a mechanical set of points we use a transistor switch.
that ign system works identically to the point style system in my old 70 monte carlo.
points close(switch closed) current flows through the coil. points(switch) opens current quits.
now a secondary current is induced as the mag field collapses a secondary voltage is induced.
spark at the plug.
this cwap aint hard but you must do a tad of reading to understand how to use your meter and what you should expect to see.
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Mr, Rodbolt - I agree I am full agreement with you on my need to read and figure out how this works - like I have said I have the service manual and I have read a good bit of the post on this forum but I still cant find a diagram for the ignition switch, kill switch, buzzer and tachometer - I am starting to believe that the problem is in that area - If you know where I might find this diagram for the remote control like the one in the attachment I would be most gratefulComment
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