mercruiser won't fie...HELP!!!

[coroname]

I have a 93' Sea Ray with a 4.3L mercruiser stern drive and can't get it to fire. It will turn over and sounds great, just won't fire up. I changed the distributor cap, ignition sensor, rotor & plugs. If I wiggle the shift interrupt switch with a screwdriver while trying to start it, it then tries to fire, but still does not? HELP PLEASE!I am not getting spark from the coil. When I check wiring from the ignition module the purple and grey have power, but the wht/grn and wht/red don't. Those grn and red wires go to the ignition sensor. Should there be power? Also, I replaced the coil yesterday, but still no spark? However, when we are trying to start it and we use a screwdriver and wiggle the interrupt switch, it sounds like it wants to start? Hgh! This is so frustrating! Last week, when we started this process, it did start for a brief moment, but then cut out - never to start since. My husbands vote it sell the boat, but I say NEVER!! LOL

 

[crazylegs68]

Re: mercruiser won't fie...HELP!!!

you might try to jumper the interrupter switch it may be bad
2?

 

[xltier]

Re: mercruiser won't fie...HELP!!!

I have a 93' Sea Ray with a 4.3L mercruiser stern drive and can't get it to fire. It will turn over and sounds great, just won't fire up. I changed the distributor cap, ignition sensor, rotor & plugs. If I wiggle the shift interrupt switch with a screwdriver while trying to start it, it then tries to fire, but still does not? HELP PLEASE!I am not getting spark from the coil. When I check wiring from the ignition module the purple and grey have power, but the wht/grn and wht/red don't. Those grn and red wires go to the ignition sensor. Should there be power? Also, I replaced the coil yesterday, but still no spark? However, when we are trying to start it and we use a screwdriver and wiggle the interrupt switch, it sounds like it wants to start? Hgh! This is so frustrating! Last week, when we started this process, it did start for a brief moment, but then cut out - never to start since. My husbands vote it sell the boat, but I say NEVER!! LOL

i had that problem and it was a bad connection in the big connector plug.i pushed it in and clamped it.i think that wh/red is suppose to have power.i think there was a diagram on that a while back.maybe try a search.

 

[Don S]

Re: mercruiser won't fie...HELP!!!

you might try to jumper the interrupter switch it may be bad
2?

If you "jumper the interrupter switch" it won't start at all.
Disconnect the white/green wire from the terminal block for the shift interrupt and it might. but don't jumper it.

 

[crazylegs68]

Re: mercruiser won't fie...HELP!!!

If you "jumper the interrupter switch" it won't start at all.
Disconnect the white/green wire from the terminal block for the shift interrupt and it might. but don't jumper it.

my bad got it backward sorry!

 

[coroname]

Re: mercruiser won't fie...HELP!!!

thank you all for you advise.

Rail - what wire did you replace exactly?

 

[Don S]

Re: mercruiser won't fie...HELP!!!

Rail has a Volvo, and you have a Mercruiser. Completely different ignition systems.
If you follow the troubleshooting chart, it will teill you where the problem lies. Don't just start chasing the "This fixed mine" threads. Many don't have the same system you do.

 

[coroname]

Re: mercruiser won't fie...HELP!!!

Don,
We looked over the chart you supplied and this is where we are now,
we have 12 volts to the coil, and 12 volts on the red/wht wire, checked the tack, checked the ignition switch. Could it be a loose wire in the shifter control box?? Or, if it is what we are thinking also, could it be the ignition module? And if it is, does anyone know where we can get one overnighted to us? I need it tomorrow!!!

 

[Don S]

Re: mercruiser won't fie...HELP!!!

Like I said earlier, disconnect the white/green wire from the shift interrupt switch terminal block. If you then have spark, you have a shift interrupt problem. If nothing changes, then follow the chart.
When you follow the chart, don't use what you think you checked and when, DO THE TESTS as described and follow the chart. It'll tell you where the problem is.
As far as getting a part tomorrow? It was 8:16 on the West coast when you posted, so I doubt anyone is going to be open anywhere for you to order it at this hour, even if you could order 24 hours a day, they won't be able to ship that quick. Besides, don't have a clue where you are even located. You might try your local Mercriser dealer in the morning.

 

[coroname]

Re: mercruiser won't fie...HELP!!!

So that I am clear on what you arer saying, you want me to disconnect the wht/grn wire from the shift interrupt switch terminal block, then see if there is spark by trying to start? or how do you want me to see if there is spark?

Also, on the chart you provided, I have a question there too. Where would I find, or what exactly is the spark gap tester that would work in the step on tbe chart that is the biggest box "remove high tension -lead...."? The spark gap tester we have is a thin circular gadget with different widths of square-shaped wire around the outside, we use it to gap the spark plugs. Not really sure how make that go from coil tower to ground??

 

[coroname]

Re: mercruiser won't fie...HELP!!!

Thank you so much, I can't express enough how much we appreciate your help.

My husband is on his way home to help me try again, but he asked me to ask you one question before we start working again.. Could it be a loose wire in the shift control box - where you actually shift the throttle? Reason why is, the boat was working fine all last summer and into the fall. Then I complained because the throttle was gettting hard to shift. I asked him to replace the cables or whatever needed to be replaced. He removed the shift or throttle assembly from the side of the boat and greased them, and also greased the cables at the motor, and said it was corrected. Could he have done something or bumped something that would cause this to happen?

 

[paulrfrancisco]

Re: mercruiser won't fie...HELP!!!

You said in your earlier post that you wiggled the shift interupter and it fired... Now you say it was stiff shifting and this is a classic problem where it will stall when shifting out of foward or out of reverse... due to a bad lower shift cable... My bet its a bad, stickey cable, and once its replaced, and properly adjusted you probably should be good to go...

 

[coroname]

Re: mercruiser won't fie...HELP!!!

Sorry for any confusion, let me clarify.
Last fall it was stiff and hard to shift. Then, it was "greased", then boat wouldn't fire. It did fire when we wiggled a scredriver near the roller in the "V" area on the assembly. But, it then died and so we started this journey... Now we have replaced several parts and tried numerous "tests" and still can not get it to fire or fire and stay running.

 

[searay3]

Re: mercruiser won't fie...HELP!!!

You cannot 'grease' a shift cable on a merc. It causes enough drag to actuate the shift interrupt switch. Only one fix for a stiff cable, replace it. Also, if you have a worn out cable, when replacing, check the other rubber. U-Joint bellows etc.

 

[paulrfrancisco]

Re: mercruiser won't fie...HELP!!!

Also, just for kicks, While cranking it, jiggle the shift/throttle lever.. it may be in a position where the interupter is engaged.. sometimes it may not be completely in the dedent for neutrual...

 

[Don S]

Re: mercruiser won't fie...HELP!!!

Like I said earlier, disconnect the white/green wire from the shift interrupt switch terminal block. If you then have spark, you have a shift interrupt problem.

For the third time, disconnect the white green wire.
It completely eliminates the shift interrupt system, cable and anything else
There is nothing in the shift/throttle control that will cause this. It may have an emergency kill switch, but if that was the problem you wouldn't have power to coil (purple wire) and you said you did.

 

[JustJason]

Re: mercruiser won't fie...HELP!!!

you named your own problem on post 13.
Don't know how obvious i can make that.

 

[coroname]

Re: mercruiser won't fie...HELP!!!

******** FINAL REPORT *******

MANY THANKS FOR ALL THE ADVICE FROM EVERYONE!!!!
As it turns out, it was a long lesson, but relatively inexpensive one to learn. Although many of you may get a chuckle out of the simplicity of it, only one of you came up this advise. The winner and who now has my loyal following is Ed @ sterndrives.com . His advise was as follows:
“A word of caution. Damage, injury or death can result if extreme caution is not taken. Always stay clear of any potentially moving parts. Gas fumes can ignite and cause a fire and/or explosion so make sure you have no gasoline fumes in the boat. Exhaust can kill you. Make sure you have adequate ventilation. Safety comes first.
Here is another trick we use to rule out the possibility of a bad dash harness or tach or lanyard... we simply unplug the main harness from the engine. Then we hook up a jumper lead from the battery positive to the positive pole on the coil (purple wires). This gives you a sure positive source to the ignition.
This next step will cause the engine to crank and possibly start so stay clear of the belts and pulleys.THE COIL JUMPER LEAD will HAve to be removed to turn off the engine if it starts.
Make sure you have water hooked up to a flushett to the drive in case it starts.
We use a jumper wire to jump a positive to the starter solenoid terminal (small yellow with red stripe) to get the engine cranking.
Hopefully one of these items will reveal the problem.
It's almost never the module itself.”

 

[Don S]

Re: mercruiser won't fie...HELP!!!

Then we hook up a jumper lead from the battery positive to the positive pole on the coil (purple wires). This gives you a sure positive source to the ignition

You told us you had power there, remember post #8

Don,
We looked over the chart you supplied and this is where we are now,
we have 12 volts to the coil, and 12 volts on the red/wht wire, checked the tack, checked the ignition switch. Could it be a loose wire in the shifter control box??

If his hot wire worked, it only worked because there really wasn't 12 Volts on the coil where you said there was. It's just that simple.

 

[coroname]

Re: mercruiser won't fie...HELP!!!

Don, Don, Don,
I really feel like you need a beverage, or at least something to loosen you up. Must your negative tone never end??? Of all the people I have chatted with regarding this situation, I swore I never would fill you in on the exact solution to the problem for that very (negative) reason. But, alas I MUST just to prove you wrong.

(everyone else get ready to have a great chuckle on me this Friday!! )

THE MAIN HARNESS WAS NOT PROPERLY PLUGGED IN. AND YES, THERE WAS AND STILL IS 12 VOLTS ON THE COIL WHERE I SAID THERE WAS! Follow THIS chart and you will see, wiggle the main harness off just a touch and check the voltage then, partner!

IT IS JUST THAT SIMPLE!