Ignition/spark issue with V8 Thunderbolt V in my 2001 Rampage

[2001 Rampage]

Hello! I have read some of your posts and you seem extremely knowledgable and they were helpful. I'm learning as I go. My boat suddenly died while about 3/4 throttle (also after hitting a hard wave...not sure if it's coincidence). I don't have spark. I've replaced the cap and rotor (needed badly), the ign sensor in the distributor, and the coil. I am going down your troubleshooting guide. I have a question...would a faulty/bad tachometer affect the module or keep it from promoting spark? I verified the gray wire going into the module and it's designated as the tach on the a wiring diagram I have. Also...if I disconnect the tach wire from the coil, I have 12 volts at coil with key on and 12 volts coming out of module (white/red, to the ign sensor inside the distributor)...when I connect the tach wire to the coil, it shows about 9 volts at the coil (+) and the same coming from the module..is this normal? If I leave the key on and the gray wire connected to the coil, the coil gets really hot. Sorry if that's confusing.

Also- starting at the beginning of the troubleshooting diagram: checking the tach/ tach wire to be sure it's not grounded. So, I disconnected my gray tach wire from my coil, I disconnected the plug in harness from my module that the gray wire uses to go into the module, and I disconnected the gray wire from my tachometer in the dash. I then tested both ends of the gray wire (the coil end and the tach end) by placing my positive/Red lead from my voltmeter on a 12 volt source (I used the red wire plugged into the ignition switch) and placed my black lead from my voltmeter to the dangling gray wire that was once connected to my tachometer...it showed a completed circuit, 12 Volts. I did this from the coil end as well, same thing. If all those are disconnected, I shouldn't be able to complete the circuit, correct? So, does this mean my tach wire is grounding somewhere between the engine and the dash?

Something interesting also...In the 5th bubble of the troubleshooting guide, I tried to check for spark at the coil by rapidly striking the wht/grn lead from the module against ground...I couldn't get my spark tester to show that the coil was firing. But, because I was curious, I re-connected/swiped the tach wire to the coil, and the spark tester came on pretty bright.

Keep in mind again that I replaced my ign. sensor, coil, cap and rotor. I guess, in truthfulness, I'm looking for something to fix besides the expensive module. I don't want to replace the module and it be something simple like the tachometer, a grounded wire, or some other sensor. Can a faulty ignition switch cause this? Or one of the sensor, like the oil pressure sensor? I don't believe it has a knock sensor (if they are attached to the cap, there is not one). Also, I eliminated the "Run/Off" switch under my throttle by bypassing it.

Thanks for any help. I appreciate it.

 

[greno]

Ok, you say you hit a wave and the engine died and now you have no spark.
Do you have any type of kill switch on your ignition? If so, check the wiring there first.

 

[alldodge]

So, I disconnected my gray tach wire from my coil, I disconnected the plug in harness from my module that the gray wire uses to go into the module, and I disconnected the gray wire from my tachometer in the dash. I then tested both ends of the gray wire (the coil end and the tach end) by placing my positive/Red lead from my voltmeter on a 12 volt source (I used the red wire plugged into the ignition switch) and placed my black lead from my voltmeter to the dangling gray wire that was once connected to my tachometer...it showed a completed circuit, 12 Volts.

There should be no connection for ground from the Gray wire with both ends of the gray wire being disconnected (At the tach, and - side of coil)

 

[achris]

Leave the grey (tacho) wire off the coil and put all the rest back on. Crank the engine and check for spark.

If you have spark, then it's the wire or the tachometer. Reconnect the grey wire at the coil, disconnect it at the back of the tacho. Check for spark. If you have spark replace the tacho. No spark, find where the grey wire is damaged and repair it.

Chris....

 

[2001 Rampage]

Thank you, Chris, I appreciate your help and reply. So, since I can ground a circuit through my gray wire when both ends are disconnected (at the coil and at the tach, also from the module), then it appears the gray whire is broken/grounded somewhere between the engine and the dash...that's what your saying, correct?

Also, I checked for spark with the gray wire off the coil and everything else back on...no spark.

 

[2001 Rampage]

Questions: Can a faulty tachometer cause the no-spark issue? Since it also goes into the module, could the module not be promoting spark because the tach is not working properly? If the tach is disconnected (at the tachometer), will the module still promote spark?

Also, imagine that my tach wire is disconnected from my coil, and the harness that houses the tach wire is disconnected from the module. And my tachometer is disconnected at the tachometer. Now...I can complete/ground a circuit on the loose tach wire at my coil. So now imagine all stays the same, but I pull apart the main wiring harness that connects the engine wires and all to the wire conduit/loom that goes to the front of the boat (this is the main connection/harness that is attached to the rear of the engine). NOW I can't complete a circuit/ground with the loose tach wire at the coil. Would it be correct to assume that my gray tach wire must be broken/grounded somewhere between that main harness and the guages? Or is there a reason that it should still be grounding that I don't know about.

 

[Scott Danforth]

Questions: Can a faulty tachometer cause the no-spark issue? .

yes. hence the reason Chris said disconnect from both end.

 

[2001 Rampage]

yes. hence the reason Chris said disconnect from both end.

Thanks, and I get that. I guess I was simply wondering if the tacho by itself could be the reason for no-spark, rather than a broken/grounded wire...but if the tacho is disconnected, it wouldn't be given a signal to the module, and that itself would cause the module not to promote spark, correct? So by doing that, how can one determine it was the tacho or simply because the tacho wasn't connected. This is so much easier on vehicles. Sorry for my ignorance.

So...I need some more verification...imagine now that I have again disconnected the main wiring harness on the engine that connects the wiring from the dash to the wiring on the engine (the gray tacho wire goes into and out of this harness). Since that eliminates 12 volts from my dash, I connected a wire lead to my positive on my battery at the back of the boat and ran the other end of the wire to my dash. I placed my voltmeter's read lead into the hot/positive wire (that goes to my battery) and placed the black lead from my voltmeter onto the dangling/disconnected gray wire at my tachometer...a circuit is completed, 12 volts. This also tells me that there is a short in the gray wire between the dash and the disconnected engine harness, correct? OR does that gray wire connect to anything along the way? Does anyone know? I was under the assumption that the gray wire from my tach should go through the coduit, through the harness, and to the coil and module only. Is this correct?

Do you hate me yet? Thanks for any help.

 

[nola mike]

If the gray wire is grounded, you won't get spark. If you've disconnected it at the coil and still aren't getting spark, that isn't your problem. The tach doesn't do anything for the ignition system unless it's malfunctioning and grounds out your coil. If your gray wire is disconnected on both ends, you shouldn't get 12v when you connect your ground lead. Could also check resistance of the gray wire with a ground--should be infinite if disconnected.

 

[2001 Rampage]

Thank you! So I found the problem...I tore into the boat to get at all the wire looms from the front of the boat to the back. After having all possible gray tacho wires disconected from every source (the coil, the module, the tach) I still had it showing grounded. I disconnected the main harness at the engine that goes to the dash...still showing ground from wire at tacho in dash. Disconnected harness under dash...no short at tacho, checked that harness. showed short. That narrowed it to the wire conduit that goes to the engine. After removing panels etc...i found where some idiot had screwed a screw through the back of the boat to attach a ladder. It went straight into the wire conduit. Didn't seem to hurt the wires at first (been over a year, maybe two)...hitting that bump was just enough to cause a wearing tacho wire to ground to that screw. UGH! Yes, I was the idiot. It was the smallest nick. That was the problem, boat runs great. Thanks for all you help.

 

[2001 Rampage]

[No message]

 

[stang32]

good find.